BCSC Plastics Flashcards
Are capillary hemangiomas in children benign or malignant?
Benign, but may cause mass effect
When do capillary hemangiomas usually present?
birth to first few weeks of life, enlarging over first 6-12 months
What percent of capillary hemangiomas resolve within the first 4-5 years of life?
75%
Is CVS a risk factor for capillary hemangioma?
Yes
How can MRI be used to distinguish capillary hemangiomas from other vascular malformations?
MRI will show fine vascular channels and high blood flow
What part of the orbit do capillary hemangiomas have a propensity for?
superonasal quadrant
What are the major complications of capillary hemangiomas?
Amblyopia, strabismus, and anisometropia
What are possible treatments for capillary hemangiomas?
topical or systemic beta blockers, steroids, surgical excision
What is the most common benign neoplasm of the orbit in adults?
Cavernous hemangioma
What is the histology of the cavernous hemangioma?
The lesions are encapsulated and composed of large cavernous spaces containing RBCs. The walls contain smooth muscle
Are arteriography and venography useful in evaluation of cavernous hemangiomas?
No, there is little communication with the systemic circulation
What is the management of cavernous hemangioma?
Surgical excision after imaging if there is compromise of ocular function
Are hemangioperictyomas common?
No
What is the histology of the hemangiopericytoma?
Plump pericytes surround a rich capillary network
When do lymphatic malformations (lymphangiomas) generally present?
Within the first decade of life in the orbit
What is the histology of the lymphatic malformation?
They generally contain both lymphatic and venous components and are characterized by large, serum-filled channels that are lined by flat endothelial cells
Are lymphatic malformations technically neoplasms?
No, because their endothelial cells do not proliferate
What are the features of lymphatic malformations on MRI?
multiple grape-like cystic lesions with fluid-fluid layering of the serum and red blood cells
How can a venous malformation be diagnosed?
With demonstration of engorgement on spiral CT during a Valsalva maneuver (decreasing venous return)
What is the management oforbital venous malformations?
Conservative, with surgical excision only if there is vision-threatening compressive optic neuropathy; embolization with coils may also be employed
What are arteriovenous fistulas?
acquired lesions caused by abnormal direct communication between an artery and a vein
What are the possible causes of an AV fistula?
Trauma or degeneration
What are the 2 forms of AV fistula?
Carotid cavernous fistula (typically occurs after a basal skull fracture) and Spontaneous Dural Cavernous Fistula (degenerative process in older pts with HTN and atherosclerosis)
Do carotid cavernous fistulas have high blood flow?
Yes
What are findings associated with carotid cavernous fistula?
Tortuous epibulbar vessels, audible bruit, pulsatile proptosis
How does a carotid cavernous fistula cause damage?
Bypass of the capillary network results in ocular ischemia; Direct passage of blood into the venous system results in venous outflow obstruction –> increased IOP, choroidal effusions, blood in Schlemm canal, nongranulomatous iritis, increased cavernous sinus pressure leading to CN III, IV, and VI palsies
How do Dural Cavernous Fistulas occur?
small meningeal arterial branches communicate with venous drainage
How does chronic red eye occur in Dural Cavernous Fistula?
Arterialization of the conjunctival vessels
How is embolization of AV fistulas usually accomplished?
endovascular transarterial route
What are the types of neural tumors of the orbit?
optic nerve gliomas, neurofibromas, meningiomas, and schwannomas
Are optic nerve gliomas benign or malignant?
They are benign in the first decade of life, but can be malignant if onset is in the adult male
What is the prognosis for malignant optic nerve gliomas?
Very poor – usually death within 6-12 months even with treatment
What percent of optic nerve gliomas are associated with neurofibromatosis?
50%
What are the clinical findings of optic nerve glioma?
gradual, painless, unilateral axial proptosis associated with loss of vision and an afferent pupillary defect
What is the gross pathology of the optic nerve glioma?
Smooth, fusiform intradural lesion
Where do optic nerve gliomas in patients with NF usually proliferate?
the subarachnoid space
What are the findings of optic nerve glioma on CT or MRI?
fusiform enlargement of the optic nerve with sterotypical kinking of the nerve
What are the possible treatment options for optic nerve glioma?
Observation only, surgical excision, radiation therapy, radiation therapy
Of what are neurofibromas composed?
proliferating Schwann cells within nerve sheaths with occasional axons, endoneural fibroblasts, and mucin
What are the two types of neurofibromas?
PlexiformNeurofibromas and Discrete Neurofibromas
Which type of neurofibroma (plexiform or discrete) is easier to excise surgically?
Discrete
In which form of neurofibromatosis do plexiform neurofibromas usually occur?
NF 1
What is the inheritance of NF 1?
autosomal dominant with incomplete penetrance
What are the clinical findings in NF 1?
Plexiform neurofibromas of the lateral aspect of the upper eyelid (S-shaped contour of lid), pulsating proptosis, optic nerve glioma
What are meningiomas?
Invasive tumors arising from the arachnoid villi
What are the findings of meningioma on neuroimaging?
diffuse tubular enlgargement of the optic nerve with contrast enhancement. On CT, calcification may be seen within the meningioma referred to as tram-tracking
What is the most common primary orbital malignancy of childhood?
Rhabdomyosarcoma
What is the average age of onset of rhabdomyosarcoma?
8-10 yrs
What is the common clinical picture of rhabdomyosarcoma?
child with sudden onset, rapidly-progressive unilateral proptosis with discoloration of the eyelids; ptosis and strabismus may also be present
From what do rhabdomyosarcomas arise?
Undifferentiated pluripotential mesenchymal elements of the orbital soft tissues (not from the extraocular muscles)
What are the 4 categories of rhabdomyosarcoma?
Embryonal, Alveolar, Pleomorphic, Botryoid
What is the common management of rhabdomyosarcoma?
Biopsy via anterior orbitotomy, surgical excision if there is a pseudocapsule, chemo and radiation, possible exenteration
What is the most common form of rhabdomyosarcoma?
Embryonal (80%)
Which form of rhabdomyosarcoma has the worst prognosis?
Alveolar, 10-year survival rate 10%
Which form of rhabdomyosarcoma has the best prognosis?
Pleomorphic, 97% survival rate
What portion of orbital tumors are lymphoproliferative neoplasms?
20%
What is the most common type of orbital lymphoproliferative disease?
Malignant non-Hodgkin B-cell lymphoma
What percent of orbital lymphomas are MALT lesions?
40%-50%
What percent of patients with orbital MALT will develop systemic disease at 10 years?
50%
What is the classic clinical presentation of a lymphoproliferative lesion?
Gradually progressive painless mass
What is the classic clinical appearance of a lymphoproliferative lesion?
Salmon patch underneath the conjunctiva or located anteriorly in the orbit
What type of biopsy is preferred for lymphoproliferative lesions?
Open biopsy
What percent of orbital lymphoproliferative lesions have on diagnosis or will have associated systemic disease within 5 years?
50%
What is the treatment of choice for localized orbital lymphoproliferative lesions?
Radiation, with a dose of 2000 to 3000 cGy
What is the most common presentation of Langerhans cell hystiocytosis in the orbit?
A lytic lesion of the superotemporal orbit with associated orbital inflammation (which may be confused initially for infectious orbital cellulitis)
What are the 4 types of adult xanthogranuloma of the orbit (in order of frequency)?
1) Necrobiotic xanthogranuloma (NBX), 2) Adult-onset asthma with periocular xanthogranuloma (AAPOX), 3) Erdheim-Chester disease (ECD), 4) Adult-onset xanthogranuloma (AOX)
What do most lacrimal gland masses represent?
Non-specific inflammation of the lacrimal gland (dacryoadenitis)
What is a common dichotomy of lacrimal gland tumors?
Epithelial origin vs. non-epithelial origin
What is the most common epithelial tumor of the lacrimal gland?
The pleomorphic adenoma (benign mixed tumor)
What is the common clinical presentation of a pleomorphic adenoma of the lacrimal gland?
Patient in the 4th or 5th decade of life presenting with slowly progressive, painless downward displacement of the globe with axial proptosis
Should a suspected pleomorphic adenoma of the lacrimal gland be biopsied?
No, it should be completely excised surgically maintaining an intact pseudocapsule
What is the most common malignant tumor of the lacrimal gland?
The adenoid cystic carcinoma (cylindroma)
What percent of patients with orbital neuroblastoma survive?
90% if diagnosed before age 1, 10% if diagnosed after age 1
What is the most common type of leukemia to metastasize to the orbit?
Acute lymphoblastic leukemia
What are the two most common metastases to the orbit?
Breast and lung tumors
What is the most common orbital metastasis in women?
Breast carcinoma
What is the most common orbital metastasis in men?
Bronchogenic carcinoma
What part of the face do Le Fort fractures involve?
the maxilla
What is a Le Fort I fracture?
a low transverse maxillary fracture above the teeth with no orbital involvement
What is a Le Fort II fracture?
a pyramidal fracture involving the nasal, lacrimal, and maxillary bones, as well as the medial orbital floor
What is a Le Fort III fracture?
craniofacial disjunction with involvement of the orbital floor and medial and lateral orbital walls
What is craniofacial disjunction?
A condition in which the entire facial skeleton is completely detached from the base of the skull and suspended only by soft tissues
What are the sites of fracture in a tripod fracture of the zygomaticomaxillary complex (ZMC)?
the lateral orbital rim, inferior orbital rim, zygomatic arch, lateral wall of the maxillary sinus
Are orbital roof fractures more common in adults or children?
Children. Since the frontal bone has not pneumatized yet in children, frontal trauma is more likely to extend to the orbital roof in children, whereas in adults, the frontal sinus acts as a crumple zone and dissipates energy of frontal impacts
What is another name for a direct medial orbital fracture?
A naso-orbital-ethmoidal fracture
What are the common clinical characteristics of a nas-orbital-themoidal fracture?
Depressed bridge fo the nose and traumatic telecanthus
What is an indirect medial orbital fracture?
A fracture of the medial orbit resulting from a blowout fracture of the orbital floor
What are the common physicial sings of an orbital floor fracture?
Eyelid edema and ecchymosis; diplopia with limitation of upgaze, downgaze, or both; enophthalmos and ptosis of the globe; hypoesthesia in the distribution of the infraorbital nerve; orbital and eyelid emphysema
What is an exception to initial observation of an orbital floor fracture?
Inferior rectus trapping beneath a trapdoor fracture (IR in maxillary sinus on CT) in pediatric patients
In which situations is surgery advisable in the case of an orbital floor fracture?
1) Diplopia with limitation of upgaze and/or downgaze within 30 degrees of primary position with positive forced ductions 7-10 days after injury and with radiologic confirmation; 2) Enophthalmos that exceeds 2mm and is cosmetically unacceptable to the patient; 3) Large fractures involving at least half of the orbital floor, particularly when associated with large medial wall fractures (determined by CT)
Can MRI be safely performed with a BB in the orbit?
Yes
Should BBs be removed from the orbit when found?
Usually, they are best left in place
What are the 5 surgical spaces within the orbit?
1) subperiorbital (subperiosteal) space (a potential space); 2) extraconal space (outside the muscle cone, between the cone and the periorbita); 3) episcleral (sub-Tenon) space (between Tenon capsule and globe); 4) intraconal space (inside muscle cone); 5) subarachnoid space (between optic nerve and nerve sheath)
Which type of orbitotomy incision provides the best cosmetic result when attempting to access the supraorbital rim?
An upper eyelid crease incision (rather than an incision directly over the superior orbital rim)
What approach is now usually used to perform an orbital decompression?
Transconjunctival incision with lateral cnatholysis to disinsert and evert the lower eyelid for exposure of the inferior and lateral orbital rims. This incision can be extended superonasally with a transcaruncular approach to access the medial orbital wall for bone removal and decompression