------------------------------------------------------------------------------ TITLE: ENT APPROACH TO ORBITAL TUMORS SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: 5 November 1991 RESIDENT PHYSICIAN: Lane F. Smith, M.D. FACULTY: Karen H. Calhoun, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------ "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. IMPORTANT ANATOMY A. In General 1. Orbit is a quadrilateral pyramidal cavity composed of seven bones. 2. The posteromedial orbital floor is the weakest portion. 3. There are no lymphatics in the orbit. B. Inferior Orbital Wall 1. Composed of orbital plate of maxilla (largest portion) zygomatic bone anterolaterally and orbital plate of the palatine bone. 2. The orbital floor is separated from the lateral wall by the inferior orbital fissure, no sharp line of demarcation from medial wall. 3. Canal for infraorbital nerve runs here and weakens this portion of orbit. 4. Inf. oblique muscle attaches anteromedially here. C. Medial Orbital Wall 1. Composed of frontal process of maxilla, lacrimal bone, lamina papyracea of ethmoid, and part of lesser wing of sphenoid. 2. Contains the optic foramen (which is not located at the geometric apex of the orbit) and foramina for ant. and post. ethmoid arteries. 3. Anteriorly, lacrimal fossa which contains the lacrimal sac. 4. Distance between post. ethmoid foramen varies from 4mm to 7mm. 5. The optic foramen contains optic n. and ophthalmic artery. 6. The posteromedial orbital floor is the weakest portion of the orbit. D. Lateral Orbital Wall 1. Composed of frontal process of the zygoma, greater wing of sphenoid lateral to optic foramen. 2. Whitnall's tubercle, a bony prominence located just deep to vein and just above midpoint of lat. wall, lateral canthal ligament attaches here. 3. Inf. orbital fissure contains: a. Path of communication between orbit and infratemporal and pterygopalatine fossae. b. Maxillary division of trigeminal n. (V2). c. Infraorbital artery. d. Branches of sphenopalatine ganglion. 4. Superior orbital fissure makes boundary between lateral orbital wall and superior wall. a. Posteriorly communicates with cavernous sinus and middle cranial fossa. b. Transmits: (1) Oculomotor n. (CN III) (2) Trochlear n. (CN IV) (3) Abducens n. (CN VI) (4) Terminal branches of ophthalmic n. (CN V1) (5) Superior ophthalmic vein. E. Superior Orbital Wall 1. Composed of the orbital plate of the frontal bone, with a small contribution from the lessor wing sphenoid. 2. Anterolaterally fossa for lacrimal gland. 3. Medially 5mm deep to rim, the trochlea inserts. F. Orbital Fasciae 1. Periorbita. a. Is the periosteum lining the bony wall and is a continuation of the dura mater from the optic foramen and sup. orbital fissure. b. Superiorly forms superior oblique tendon. c. Inferomedially splits to enclose the lacrimal sac. d. Septa divides orbital fat into lobules. e. Subperiosteal space: surgical plane between orbital walls and periosteum. 2. Orbital septum or palpebral fascia. a. Covers the entrance of the orbit and is a continuation of the periorbita at the rim. b. On upper lid unites with levator aponeurosis. c. On lower lid fuses with tarsus and inf. rectus. d. Attaches to posterior aspect of levator aponeurosis. 3. Bulbar fascia or tenons capsule. a. A fibrous sheath surrounding entire globe except cornea. b. Separates eye from orbital contents. c. Anteriorly perforated by tendons of rectus muscles. d. Surgical space between bulbar fascia and globe is the episcleral space. 4. Muscular fascia. a. Formed by the fibrous sheathes of the extraocular muscles. b. Thickening of this process from the medial and lateral recti forms the medial and lateral canthal tendons. c. Canthal tendons and fascia from medial lat and inf. recti blend together to form a fibrous sling supporting the globe known as the suspensory ligament of Lockwood. G. Orbital Vessels 1. Main blood supply is ophthalmic artery, a branch of internal carotid. 2. The ant. and post. ethmoidal branch of the ophthalmic and exit medial orbital wall through ant. and post. ethmoidal foramina. 3. Lower part of orbit supplied by infraorbital artery, a branch of the IMA which a branch of the ECA. 4. Venous drainage of the orbit is valveless with numerous interconnections leading to easy spread to the cavernous sinus. H. Extraocular Muscles 1. Arise from a common tendinous ring, the annulus of Zin which is at the apex encircles the sup. orbital fissure and optic foramen. 2. As mentioned, muscular fasciae fuses with the bulbar fascia anteriorly. 3. Fasciae and muscles form the muscular cone which separates central from peripheral surgical space. I. Four Surgical Spaces 1. Subperiosteal space; lies between periosteum and bony orbit. 2. Episcleral space; lies between bulbar fascia and globe (sclera). 3. Central surgical space. a. Lies under muscular cone. (See above.) b. Contains: (1) Optic n. (2) CN III (3) CN V (Nasociliary branch.) (4) CN VI (5) Ophthalmic artery and its major branches. (6) Ophthalmic veins. 4. Peripheral surgical space. a. Lies outside of muscular cone. b. Contains orbital fat. c. Contains CN IV. J. Lacrimal System 1. Secretory system consists of two major types of glands; basic and reflex secretors. 2. Basic secretors: consists of numerous small goblet cells in conjunctiva, tarsal meibomian glands and accessory lacrimal glands of the subconjunctiva of the upper lid. 3. Reflex secretors consists mainly of the lacrimal gland which is located in the lacrimal fossa in the lateral orbit superiorly and anteriorly. This gland contains two to six excretory ducts. 4. Excretory system. a. Tears from the basic and reflex secretions are pumped by eyelid action medially. b. There is a lacrimal punctum in the upper and lower lid. (The punctum is the opening of the canaliculus.) c. Both the superior and inferior canaliculus have a 2mm vertical component which makes a 90 degree turn to a horizontal component 8mm in length. d. The upper and lower canaliculus join to form a canaliculus which empties into lacrimal sac just post. and sup. to the center of its lateral wall. e. The lacrimal sac empties into the nasolacrimal duct which opens in the inferior nasal meatus. K. Eyelids 1. Anterior lamella: consists of skin and orbicularis muscle. 2. Posterior lamella consist of tarsus and conjunctiva. II. EVALUATION OF ORBITAL TUMORS A. A good history of onset of lesion, diplopia, visual disturbance, loss of visual acuity, pain, photophobia, acute or chronic onset, etc. is necessary. B. Extensive physical examination of the orbital area, periorbital area, paranasal sinuses, visual acuity, and cranial nerves. C. Radiographic studies as indicated. 1. CT scanning is the best radiographic modality for extraocular orbit. 2. Axial and coronal scans of orbit and paranasal sinuses are essential for evaluating extent of the lesion and planning surgery. D. Unilateral Proptosis 1. Graves ophthalmopathy is most common cause in adults, cellulitis (secondary to paranasal sinusitis) in children. 2. Pseudotumor second most common cause in both pediatric and adults. 3. Next most common cause in adults is paranasal sinus tumors. (See table 1.) 4. Often history, physical, plain radiographs and laboratory tests establish the diagnosis in approximately 50% of the patients. With CT scanning the yield is even higher. TABLE 1. ORBITAL TUMORS (most to least frequent causes not including orbital pseudo tumor) Adults Pediatric 1. Paranasal sinus tumors 1. Dermoids and epidermoids 2. Metastases (often breast/lung) 2. Capillary hemangiomas 3. Cavernous hemangiomas 3. Lymphangiomas 4. Lacrimal gland tumors 4. Rhabdomyosarcomas 5. Lymphomas 5. Neurofibrands & optic gliomas 6. Meningiomas 6. Leukemias and lymphomas 7. Dermoids and epidermoids 7. Metastases (often neuroblastomas) E. Initial Laboratory Tests 1. CBC: R/O infection. 2. ESR: R/O inflammatory causes. 3. Thyroid function tests: R/O Grave's Disease. 4. Calicum: R/O hyperparathyroidism and brown tumors. F. Fine Needle Aspiration 1. Very useful when a tumor can be palpated. 2. Should not be used on highly vascular lesions, such as lesions that enhance significantly on CT scanning. (Thus FNA of the orbit should probably only be used after contrast enhanced CT scans have been obtained to R/O vascular lesion.) 3. FNA mostly useful for more anterior lesions although some posterior tumors adjacent to bony walls may be reached via a radiographically-guided needle (fluoroscopy or ultrasound). G. Biopsy 1. Used wherever other modalities (CT, FNA, etc.) have failed to yield a diagnosis and prior to any radical orbital surgery. 2. Radical orbital surgery differed until permanent sections are back. Pretreat biopsies must always be performed prior to radical surgery. 3. If the lesion involves paranasal sinuses, biopsy transnasally or through a paranasal sinus approach (endoscopically, etc.) is usually easier and preferable to biopsy through the orbit. 4. If lesion is small and easily accessible excisional biopsy is preferred to incisional biopsy. H. In general a good history, physical, laboratory tests and plain fibrous should make the diagnoses in 50% of patients. III. RADIOGRAPHIC EXAMINATION OF THE ORBIT A. Plain films: Caldwell, Waters, lateral, optic foramen SMV. B. CT Scan 1. Best single radiographic modality for evaluating orbital neoplasms. 2. Can sometimes characterize tissue type of neoplastic process. 3. Can delineate extent of neoplastic process and bony destruction. 4. Optic n. sheath meningioma from optic n. glioma. Glioma causes fusiform enlargement isodense with nerve, whereas meningioma cylindrically hyperdense giving "railroad track" sign on optic n. 5. Neurofibromas often assoc. with congenital absence of greater and lesser sphenoid wings, CT shows hemogenous mass of moderate density. 6. Cavernous hemangiomas show up well with contrast as well defined mass in superolateral muscle cone without apical nerve or muscle involvement. 7. Lymphangiomas rarely enhance with contrast and are usually outside the muscular cone. 8. Dermoids and teratomas may appear anywhere in the orbit as circumscribed variegated lesions with punctate calcification. 9. Embryonal rhabdomyosarcomas, fibrohistiocystomas and lymphomas show up as average density lesions with moderate enhancement. Lymphomas are usually outside of the muscular cone. 10. Malignant tumors tend to be poorly defined with destructive bony changes. C. Ultrasound 1. Good for solid vs. cystic lesions, hemangiomas and orbital hemorrhage. 2. Modality of choice for intraocular evaluation when opacification of the lens is present and precludes direct inspection of the posterior globe. 3. Can clearly distinguish neoplastic invasion from inflammation. 4. A good adjunct to CT scan. D. Angiography 1. Good for evaluation of vascular masses. 2. Useful for suprasellar masses. 3. Useful for preoperative embolization of vascular tumor (eg. prior to removal of meningioma). E. MRI 1. Superior to CT scan in demonstration intracranial extension of mass lesions. 2. Contraindicated in the evaluation of orbits suspected to harbor metallic foreign bodies. IV. PEDIATRIC ORBITAL TUMORS A. Often requires a multidisciplinary approach involving the pediatrician, ophthalmologist, oculoplastic surgeon, otolaryngologist, neurosurgeon and oncologist. B. Congenital Developmental Cysts 1. Dermoid and epidermoid cysts. a. Present in preschool children as painless, elevated modules seen along the superotemporal orbital rim (can be deep or superonasally). b. Posterior cysts can cause proptosis. c. If cyst wall contains adnexal structures (eg. hair, sweat glands, etc.), called dermoid; if not, epidermoid cyst. d. Can rarely cause local bony erosion due to pressure. e. CT scan show low-density lucent lesion. f. Treatment is complete cyst removal (surgical technique discussed later). 2. Teratoma a. A congenital rapidly growing tumor present at birth. b. Present with dramatic exophthalmos. c. By definition contain all 3 germ layers. d. Benign tumor but can be massive and extend intracranially. e. Treatment requires combined neurosurgical and orbital approach performed soon after birth. Attempt to spare the globe. C. Vascular Tumors 1. Capillary hemangiomas. (See grand rounds 1989 Vascular Tumors by Lane Smith.) a. Reddish to bluish appearance usually present at birth or shortly thereafter. b. Usually involve upper eyelids. c. Can grow rapidly and occlude eye causing amblyopia in as short a time as two weeks. d. Usually these lesions will spontaneously involute by age 18 to 36 months. e. If causing amblyopia, severe cosmetic deformity, or frequent bleeding can use intralesional steroid injections or surgery for treatment. 2. Lymphangioma a. Appear in preschool years. b. Soft bluish masses usually in the superonasal quadrant. c. Treatment requires complete surgical removal with sparing of vital structures. D. Rhabdomyosarcoma 1. Most common childhood primary malignancy of the orbit. 2. Presents with rapidly evolving exophthalmos in young children (ages 5-10). 3. Most commonly involves superior orbit. 4. CT shows poorly defined homogenous mass. 5. An incisional biopsy through an anterior approach is used for diagnosis. 6. Treatment consists of combination radiotherapy and chemotherapy. 7. Exenteration is reserved for rare radioresistant and recurrent tumor. E. Glioma 1. Present in preschool children with loss of vision proptosis, papilledema, optic atrophy and strabismus. 2. 25-50% have systemic neurofibromatosis. 3. CT scan shows fusiform enlargement of the optic nerve. 4. Treatment varies from watchful waiting (if vision good, etc.) to removal of orbital contents. F. Fibro-osseus Tumors 1. A group of lesions characterized by replacement of normal bony architecture with tissue composed of varying amounts of collagen fibroblasts and osteoid and giant cells in differing patterns. 2. Fibrous dysplasia. a. Most frequent of the fibro-osseous tumors. Two types exist polyostotic and monostotic fibrous dysphasia. b. Occurs almost exclusively in children during the first two decades of life. c. Polyostotic fibrous dysplasia (Albright's Syndrome). (1) Multiple bone involvement. (2) Abnormal skin pigmentation. (3) Precocious puberty. (4) Usually spares the orbit. d. Monostotic fibrous dysplasia. (1) Occurs most often in face. (2) Frequently involves the orbit (3) Often involves maxilla, sphenoid or frontal bone. e. Radiographic appearance shows a sclerotic lesion with ground glass appearance. f. Biopsy necessary to confirm the diagnosis. g. These often grow rapidly in early life and then stabilize after puberty. h. Conservative surgical excision or sculpting of lesion for lesions causing symptoms. i. Radiation therapy contraindicated. 3. Ossifying fibroma. a. Similar to fibrous dysplasia but characterized by a more aggressive growth pattern. b. Radiographic appearance more demarcated from normal bone than fibrous dysplasia. c. Complete surgical excision is treatment of. Because of the sharp demarcation from normal bone this is easier to do than with ossifying fibroma. 4. Osteomas. a. Uncommon benign tumors of bone. b. Radiologically well-circumscribed extremely dense masses. c. Surgical excision is the treatment of choice. 5. Giant-cell lesions. Include giant-cell reparative granuloma, true giant-cell tumor (rarely occurs in children) and "brown" tumor of hyperparathyroidism. G. Metastatic Orbital Tumors. 1. In pediatric age group most common mets are neuroblastoma, Ewing's Sarcoma, leukemia, medulloblastoma and Wilm's Tumor. 2. Neuroblastoma. a. Presents with ecchymotic bilateral or unilateral proptosis. b. Metastases are usually to lateral orbit with bony destruction of lateral orbital wall. 3. Ewing's Sarcoma presents with abrupt hemorrhagic exophthalmos usually in second decade. V. TUMORS OF THE PARANASAL SINUSES, NASAL CAVITY AND NASOPHARYNX INVOLVING THE ORBIT A. Paranasal sinus tumors (cancer, tumors and mucoceoles) frequently extend to involve the orbit. 1. The route of spread is not thought to be secondary to lymphatics as there is no lymphatic drainage of the orbit. 2. Direct extension through the preformed pathways through anterior and posterior ethmoid foramina. 3. Tumors from the nasal cavity can extend into the orbit via the nasal lacrimal duct. 4. The infraorbital canal and inferior orbital fissure sense as a direct route for cancer invasion from the maxillary liners. 5. Dehiscence of the lamina papracea or lateral wall of sphenoid sinus allow spread from these areas to orbit. 6. The frontoethmoid, maxilloethmoid, and zygomaticomaxillary suture lines are also potential routes of spread from paranasal sinuses to orbit. 7. Periosteum of orbit forms a barrier to tumor spread. Benign tumors tend to push it aside, malignant tumors invade it. B. Carcinomas of the paranasal sinus are extremely lethal and rare, comprising only 0.2% to 0.8% of all carcinomas. These are the most common tumors to secondarily invade the orbit. Maxillary sinus is most common sinus origin to invade the orbit. C. 40-60% of all sinus carcinomas eventually cause enough orbital involvement to necessitate orbital exenteration. D. In 70% of tumors involving the orbit bone destruction is present on CT scan. E. Clinical Manifestations 1. The majority of cases are detected late, as early on patient are often asymptomatic. 2. Symptoms of orbital extension include ocular pain, visual alteration, diplopia, and photophobia. 3. Physical findings of orbital invasion include increased intraocular pressure, epiphora, ptosis, proptosis, ophthalmoplegia and optic atrophy. TABLE 2. NONOSSEOUS TUMORS ORIGINATING IN THE SINUS, NOSE AND OROPHARYNX THAT EXTEND SECONDARILY INTO THE ORBIT Mucocele primary or secondary to tumor Squamous cell carcinoma Inverting papilloma Mucoepidermoid carcinoma Adenocarcinoma Adenoidcystic carcinoma Malignant mixed tumor Angiofibroma Lymphoepithelioma Esthesioneuroblastoma Cholesteatoma Ameloblastoma Melanoma of the sinus F. Radiographic Studies: CT scan best study. (See aforementioned section on CT scanning and other radiologic studies.) G. Biopsy of Mass Invading Orbit (See previous section.) 1. As mentioned earlier, biopsy is best obtained transnasally when possible. 2. Biopsy should be deferred until after neurosurgical consultation when radiographic studies show communication with cranial cavity, CSF leak is present or pulsation of mass. 3. If the lesion is highly vascular biopsy should be deferred or performed in the OR. 4. In general, it is best to wait until after the CT scan and possibly other radiographic studies prior to biopsy. H. Benign Neoplasms Invading Orbit 1. Generally do not invade orbital periosteum. 2. True violation of orbital fat or muscular cone infrequent. 3. Tend to push orbital contents aside and cause optic compression. 4. Tend not to have bony invasion although bony evasion via compression can occur. 5. Include: a. Inverting papilloma. b. Osteomas. c. Other osseous lesions. (1) Fibrous dysplasia. (2) Giant-cell granuloma. (3) Ossifying fibroma. d. Juvenile angiofibromas. e. Neuroectodermoid tumors. (1) Meningiomas. (2) Schwannomas. (3) Neurofibromas. f. Ameloblastoma. g. Cholesteatomas. I. Treatment of Benign Lesions Invading the Orbit 1. in general, attempt to spare orbital contents with excision. Orbital exenteration is indicated with a persistently recurring benign lesion that threatens to invade cranial cavity or when lesion threatens to attain unresectability or cause blindness. 2. Tumor may dissected from the periorbita if the periorbita elevates easily from the bony orbit during resection. If the periosteum has been penetrated the tumor may be resected with a cuff of fat and if needed a rectus muscle. 3. Inverting papillomas are usually treated aggressively with a lateral rhinotomy-medial maxillectomy approach which permits excision of lateral nasal wall, ethmoid labyrinth and lamina papyracea. 4. Osteomas. a. Often originate near the frontoethmoid suture. b. Can be approach via a coronal or Lynch incision. c. Lesion can be excused via an osteotomy. d. The floor of the frontal sinus is usually excised, frontal sinus obliteration is usually not needed, rather an indwelling stent is placed to create an epithelialized path into the frontal sinus. 5. Angiofibromas usually managed through a transpalatal approach when small and a lateral rhinotomy approach when larger. J. Malignant Lesions Invading the orbit 1. Proptosis, invasion through the orbital periosteum muscular cone and bony walls are common. 2. Squamous cell carcinomas are by far the most common. 90% of all sinus carcinomas are squamous cell. 3. Concommitant involvement of the maxillary and ethmoid sinuses are rare except in advanced tumors. 4. Pain occurs secondary to neural (perineural) involvement and is much more common in malignant than benign lesions. The development of trismus indicates involvement of the pterygoid fossa. 5. Includes: a. Squamous cell carcinoma. b. Mucoepidermoid carcinoma. c. Adenocarcinoma (important to rule out metastases if this tumor is found). d. Adenoid cystic carcinoma. e. Osteosarcoma. f. Esthesioneuroblastoma (also called olfactory neuroblastoma). g. Leiomyosarcoma. h. Malignant melanoma. VI. TREATMENT OF PARANASAL SINUS TUMORS, NASAL CAVITY, NASOPHARYNGEAL, AND OTHER TUMORS INVADING THE ORBIT A. Combination of radical surgery and radiation therapy, sometimes with chemotherapy, provides the best cure rates. B. Even with combination therapy, prognosis with orbital involvement is extremely poor with 5 year survivals ranging from 10-40%. (Worse for ethmoid and sphenoid sinus involvement, better prognosis for maxillary sinus involvement.) C. Lymphoma, rhabdomyosarcoma and plasmocytoma are usually managed with non-surgical treatment such as chemo- and radiation therapy. D. Maxillary sinus tumors with orbital invasion require radical maxillectomy and orbital exenteration. E. Malignant tumors of the superior sinuses require craniofacial resection with simultaneous orbital exenteration. The usual approach involves a coronal incision with craniotomy resection of the skull base and transfacial approach either through a rhinotomy or Weber-Ferguson incision. F. Orbital Exenteration 1. Gross invasion of the orbit as evidenced by proptosis, limitation of motion or tumor in the orbital fat or muscular cone indicates the need for orbital exenteration. 2. Perineural invasion of the optic nerve or involvement of orbital apex also is a clear indication for orbital exenteration. 3. If there is a question as to whether these structures are involved frozen section diagnosis can help with the resection. 4. A smooth elevation of the orbital periosteum indicates the orbital contents can be saved. 5. Controversy exists when there has been pre- operative radiotherapy and now there is no evidence of orbital involvement. Again, pre-operative CT scans and frozen section can guide one in these situations. 6. Previously tumor involvement of the posterior ethmoid cells (with or without orbital involvement) has been considered an absolute indication for orbital exenteration. This is now under debate. Some authors say the orbit can be spared when surgery is guided by frozen section diagnosis. 7. If only the orbital periosteum is invaded the eye can be saved and floor of orbit reconstructed with temporalis muscle sling and/or split thickness skin graft. G. En Bloc Ethmoidectomy with Medial Maxillectomy (Surgical Procedure) 1. Subperiosteal elevation of medial orbital contents and lacrimal sac, then retract globe and lacrimal sac laterally. 2. Perform a Caldwell Luc procedure with extensive removal of the anterior of the maxillary sinus. 3. Next an osteotomy separating the adjacent nasal bone from the nasal process of the maxilla is performed. Then five major bony cuts are performed. 4. An osteotome is introduced through the previously opened maxillary sinus along the inferior medial aspect of the sinus and a cut is made into the inferior meatus of the nose. (From anterior tip of inferior turbinate to posterior limits of inf turbinate. This cut ends just anterior to pterygoid plate.) 5. The next cut is made from floor of medial max. sinus parallel and just behind the nasolacrimal duct up to superior lacrimal fossa. 6. The third cut is made along the frontoethmoid suture-line beginning in the lacrimal fossa and extending to just post. to ant. ethmoid artery. 7. The fourth ant. extends just medial infraorbital nerve, along the orbital floor diagonally to meet the third cut near the ethmoid arteries. 8. The final cut is made from the posterior aspect of the floor of nose up to the posterior tip of the superior turbinate. Any final attachment of bone is then gently fractured with a to and fro rocking motion. 9. The nasal bone is returned to its normal position and the medial canthal ligament is sutured to the adjacent periosteum. The cavity is lined with split thickness skin graft. 10. Modifications on this technique can be made to include the cribriform plate, frontal sinus, orbit and nose of the orbital floor. H. Reconstruction of the Orbit 1. Can frequently be accomplished by simple placement of a split thickness skin graft in a sling to hold orbital contents in place when only floor of orbit has been removed. Some authors state that if periorbital periosteum intact no reconstruction necessary. 2. If eyelids and conjunctiva are spared after orbital exenteration, these can be sutured to residual tissue to form a new shallower socket. 3. Large defects can be repaired with temporalis, galeal, pericranial, myocutaneous and free flaps. VII. SKIN CANCER AND THE ORBIT A. Skin cancers such as squamous cell carcinoma, basel cell carcinoma or malignant melanoma if allowed to progress untreated can involve the orbit. B. Basal cell most common to encroach on orbit. C. Pathologic diagnosis important prior to any radical surgery as many of these tumors can be treated with combination therapy and thereby preserve orbital contents and function. D. Most often these lesions involve the medial canthus. E. Conley states the most important feature of management of these cancers is identification of free margins via Moh's technique or intraoperative frozen section. F. The globe can usually be saved although some of the supportive structures and appendages may have to be resected. G. Reconstruction is usually with local flaps and/or skin grafts. VIII. LACRIMAL FOSSA TUMORS AND THEIR MANAGEMENT A. The superolaterally located lacrimal gland is the sole epithelial structure in the orbit. (See aforementioned anatomy.) 1. The entire gland can usually be sacrificed with no need for artificial tears. B. Tumors here account for 10-15% al all primary orbital tumors and are equally divided between nonepithelial and epithelial disorders. 1. Nonepithelial lesions (in order of frequency). a. Pseudotumor. b. Benign lymphoid hyperplasia. c. Lymphoma. d. Sarcoid. e. Sjogrens. 2. Epithelial tumors (in order of frequency). a. Pleomorphic adenoma. b. Adenoid cystic carcinoma. c. Adenocarcinoma. d. Undifferentiated carcinoma. e. Mucoepidermoid carcinoma. f. Metastases. g. Squamous cell carcinoma. C. Signs and symptoms of lacrimal fossa tumors. (Note: often history and onset can lead to fairly accurate diagnosis.) 1. Benign mixed tumor. a. Slow, painless growth over 1 to 2 years. b. Minimally symptomatic. c. CT scan shows smooth rounded mass with no bone evasions. 2. Pseudotumor. a. Painless mass presenting over course of a few weeks to 1-3 months sometimes faster. b. Not erythematous, tender or signs of systemic infection (ie. no fevers). c. Should regress to 50% of size with 2 week trial of antibiotic. 3. Carcinomas. a. Painful (sometimes painless) fairly rapid growth. b. CT scan shows irregular margins with bony evasion or invasion. 4. Infections (eg. acute dacryoadenitis). a. Painful inflamed, erythematous. b. Progress over to days to weeks. c. Responds to antibiotics. D. Diagnosis 1. Suspected infections such as acute dacryoadenitis respond to antibiotics and need no further work-up (other than possibly CT scans and cultures). 2. Pseudotumors respond dramatically to trial of steroids; no histologic diagnosis needed. 3. All other lesions require histologic diagnoses. a. Fine needle aspiration. b. Benign mixed tumors require complete excisional biopsy. If a previous incisional biopsy has been performed, the lesion and the surgical tract with a cuff of normal tissue must be excised. c. Carcinomas can undergo an incisional biopsy with permanent sections prior to orbital exenteration or other radical surgery. E. Treatment 1. Pseudotumor: steroids. 2. Infections: antibiotics. 3. Benign mixed tumors. a. Noninvasive lacrimal fossa mass lesions are excised in total without preliminary biopsy with the expectation of a benign mixed tumor. b. The periosteum of the lacrimal fossa the main body of the gland and the conjunctiva around the excretory ducts in the palpebral lobe are removed in bloc. c. If a previous incisional biopsy has been made, the entire biopsy tract with a generous cuff of adjacent tissue is included in the resection. 4. Low-grade mucoepidermoid carcinoma: wide excision of the gland, adjacent periosteum and levator muscle. 5. Epithelial malignancies. a. Require orbital exenteration including upper lid and lateral orbital wall. b. Extradural removal of the anterolateral orbital roof is necessary. c. Defect may be repaired with skin graft and/or a temporalis muscle/pericranial flap. d. Radiation therapy and chemotherapy may be useful adjuncts to primary surgical therapy. e. Prognosis is extremely poor 8-25% 5 year survival. IX. SURGICAL APPROACHES TO PRIMARY ORBITAL TUMORS A. Lateral Orbital Tumors 1. Most location for primary orbital tumors. 2. Most common lesion located here is cystic lesions of which dermoid cyst was most common. (80% of these lesions.) 3. Most often these cystic lesions are located antero- laterally. 4. Frequently inflammatory masses can mask as tumors. B. Lateral Orbitotomy via Temporal Fossa 1. Because majority of orbital soft tissue is temporal to optic nerve most primary tumors are accessible by lateral orbitotomy. 2. Especially good for hemangiomas and dermoid/epidermoid lesions. 3. This approach is safe (endangers no important orbital structure). 4. Procedure. a. A 3 to 3.5cm incision carried straight back from lateral canthus toward superior attachment of ear. The incision can be extended up into the brow (wright incision) or can be S-shaped over brow and temporal region. b. Undermine just above temporalis fascia. c. An incision made through temporalis fascia to orbital rim through periosteum and carried superiorly and inferiorly along orbital rim. A straight line incision in the direction of the skin incision is carried posteriorly to the position edge of the zygoma. d. These superior and inferior flaps are then elevated with a periosteal elevator and retracted to expose lateral orbital wall. e. Elevate the lateral canthal tendon from Whitmalls tubercle. f. A Stryker saw is used to make incisions that are parallel and slightly converging with lines of the inferior and superior orbital margins. g. This segment of bone is then cut-fractured (usually 12mm posterior to rim). A further 10-12mm of bone can be removed with drill or rongeurs until the anterior wall of middle cranial fossa is reached. (Thereby exposing the entire post-lateral orbit.) h. Place traction suture around lat. rectus and rotate globe. i. Incise periorbita parallel to lateral rectus over palpable tumor. j. Remove tumor if not adherent to globe, optic nerve or extraocular muscles. k. Reapproximate periorbita attach lat. canthal tendon (via suture passed through drill hole in that area). Stabilize rim with 28 gauge wires or plates. l. Place drain in peripheral surgical space and apply a light pressure dressing over temporal fossa and lids. C. Surgical Approaches for Lacrimal Gland Masses 1. The lateral orbitotomy approach. a. Will give access to most lacrimal fossa masses. b. The superior osteotomy is placed more superiorly; 1cm above the frontozygomatic suture. c. If frontal sinus is extensively pneumatized, the superior osteotomy may enter its lateral portion. An otolaryngologist may need remove frontal sinus mucosa and perform sinus obliteration if frontal sinus is diseased. 2. Biopsy of lacrimal fossa mass direct approach. a. Brow incision can be used. b. Dissect down directly orbicularis muscle and orbital septum staying in extraperiosteal plane. c. Good for incisional biopsy. Not real useful for excisional biopsy. Use lateral orbitotomy. D. Medial Orbital Tumors 1. Primary orbital tumors are infrequently located nasal to the optic nerve. Less than 30% of orbital tumors occur nasal to the optic nerve. 2. The most frequent diseases in this region are due to direct extension from the paranasal sinuses. a. Infections. b. Mucoceoles. c. Carcinomas. d. Benign neoplasms. 3. Of primary orbital tumors that do occur nasal to optic nerve; peripheral nerve tumors such as meningiomas and gliomas are common. 4. Symptoms usually occur earlier than lateral orbital tumors because less room to grow which causes early displacement of the globe. 5. The majority of tumors in the nasal orbit are medial to the extraocular muscles. E. Surgical Access to Medial Orbital Tumors and Medial Orbitotomy 1. The majority of these tumors can be removed through a Lynch incision (since they lie medial to the muscular cone). a. When needed an external ethmoidectomy and/or removal of the orbital floor medial to the infraorbital nerve can also be performed through the Lynch incision. b. The medial and inferomedial spaces can be connected by dividing the medial canthal tendon, mobilizing the lacrimal sac and dividing it at the junction with the proximal duct. c. Medial rectus muscle traction aids in globe rotation thereby exposing entire medial orbit. d. This can be performed in combination with the medial maxillectomy. (See previously mentioned surgical procedure.) e. Reattach tendon, fracture middle turbinate laterally if the medial orbital wall has been resected and stabilize nasal pack for 5 days. 2. Dual surgical approach. a. Used for large tumors or when tumors are located in the central surgical cone. b. Perform lateral orbitotomy to allow temporal displacement of globe. c. Perform external ethmoidectomy and/or removal of the orbital floor via Lynch excision or medial maxillectomy using lateral rhinotomy or Weber Ferguson incision. d. Divide medial canthal tendon, mobilize lacrimal sac laterally and place medial rectus traction suture. e. Remove tumor with margins. f. Collapse ethmoid space by outfracturing the middle turbinate, stabilize with intranasal pack for 5 days. g. Reattach canthal tendon, perform a dacryocystorhinostomy. F. Inferior Orbitotomy 1. For tumors limited to anterior aspect of orbital floor (most commonly lymphomas and mets). 2. First perform a lateral canthotomy. 3. Retract lower lid inferiorly and incise the conjunctiva in the inferior fornix directly over the orbital rim. 4. Place traction in bulbar conjunctiva and rotate the globe superiorly. 5. Place malleable under globe for protection. 6. A subconjunctival mass may be exposed through orbital fat, otherwise dissect in subperiosteal plane to reach mass. 7. The conjunctiva is reapposed with 6-10 chromic. 8. Reattach lateral canthal tendon and close skin. G. Transantral Decompression 1. Can be used to reach large or posterior orbital floor tumors. 2. Can decompress orbit in unresectable disease to reduce pain or prolong lesion. 3. Incise periorbital directly over the mass. 4. By combining this with other midface exposures, extensive benign skull base neoplasms may be resected without sacrifice of vision. H. Superior Orbitotomy 1. Used to biopsy anterosuperior orbital tumor, lacrimal sac tumors (see aforementioned section) and excise smaller tumors. 2. Mobilize lacrimal sac from its fossa, mobilize the trochlea. 3. Bipolar cautery of supraorbital vessels. 4. Identify and protect supraorbital neurovascular bundle at notch. 5. Incise periosteum over mass. 6. Control orbital roof bleeders with bone wax. 7. Bluntly separate levator palpebral superior rectus and oblique until lesion exposed. 8. Dissect mass free if not adherent to other structures. If other structures involved send incisional biopsy. 9. This procedure can be combined with medial or lateral orbitotomy. I. Transfrontal or Transcranial Approach to Orbital Tumor 1. This approach is mandatory for lesions which involve both intraorbital and intracranial compartments. 2. Also used for tumors at the orbital apex in the central surgical cone and optic canal which cannot be reached by medial or lateral orbitotomy approaches. a. The posterior 15mm of the lateral orbital wall encompasses the superior fissure and cannot be removed with a lateral orbitotomy. b. Meningiomas, neurofibromas, schwannomas, and tumors of the optic nerve are often best treated with this approach. 3. A bicoronal flap is raised. 4. The posterior table of the frontal bone is removed and dura is reflected superiorly. 5. The mucosa of the frontal sinus is removed and frontal duct is obliterated (optional). 6. The orbital roof and periorbita are then opened. 7. The frontal nerve and artery, trochlear nerve and levator superior rectus complex are retracted medially or laterally (depending on location of the tumor). 8. The periorbita is closed. 9. Alloplastic materials, fascia lata or temporalis/pericranial flaps are placed over the orbit to prevent pulsating exophthalmos. J. Orbital Exenteration 1. Can remove entire contents of the orbit with or without the eyelids. 2. Usually performed for malignant orbital tumors. a. Sclerosing basal cell carcinoma. b. Squamous cell carcinoma. c. Choroidal melanoma, extrascleral spread. d. Sarcomas. e. Lacrimal gland carcinomas. 3. Procedure. a. 360 degree incision around the orbit 2-3mm outside the rim through the skin and subcutaneous tissues down to the periosteum. b. Elevate the periosteum. c. Release the medial and lateral canthal tendons and trochlea. d. Remove the lacrimal sac after dividing the nasolacrimal duct, ablate by cautery. e. At the level of the superior orbital fissure/optic canal using a large pair of mayo scissors to divide the orbital contents from the apex. f. Hemostasis achieved with monopolar cautery and pressure. g. Orbit is inspected for tumor extension, remove the sinus or orbital bones if required. h. If lids to be retained, the initial incision is made at the gray line, resecting tissue posterior to the orbicularis oculi muscle. i. Continue dissection posteriorly until periorbita reached, dissection completed as mentioned. j. Defect is filled with vaseline gauze or antibiotic soaked material, 8-14 weeks required before granulation process is completed with epithelialization of the orbit. k. Can also line the orbit with a split thickness skin graft. l. Refer for prosthesis fitting when healed. ------------------------------------------------------------------------------ BIBLIOGRAPHY 1. Sessions RB, Larson DL. En bloc ethmoidectomy and medial maxillectomy. Arch Otolaryngol 103:195-202, 1977. 2. Kennerdell JS, Maroon JC, Malton ML. Surgical approaches to orbital tumors. Clinics in Plastic Surgery vol. 15, No. 2, April 1988:273-81. 3. Stasior OG. Evaluation of the lacrimal System for Cosmetic Surgeons. Arch Otolaryngol 1982;108:495-97. 4. Byers RM, Berkeley RG, et. al. Combined therapeutic approach to malignant lacrimal gland tumors. Am Journ of Ophthamology vol. 79, No. 1:53-55. 5. Leone CR. Surgical approach to the medial retrobulbar space. Am Jour of Ophthamology vol. 96, No.1:1-5, 1983. 6. Conley J. The risk to the orbit in head and neck cancer. Laryngoscope 95; May 1985:515-23. 7. Osguthorpe JD, Saunders RA, et. al. Evaluation of and access to posterior orbital tumors. Laryngoscope 93;June 1983:766-71. 8. 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