Orbit Volume 2 Flashcards
What is the most common cause of proptosis in adults?
TAO
What condition is associated with “salmon-colored” mass of the conjunctival cul-de-sac?
Lymphoma
What condition is associated with vascular congestion over the insertion of the rectus muscles?
TAO
What condition is associated with “corkscrew” conjunctival vessels?
AVM
What condition is associated with an “S-shaped” eyelid?
NF Type I (plexiform neurofibroma)
What condition is associated with black-crusted lesions of the nasopharynx?
Phycomycoses
What rectus muscle is most commonly affected by TAO?
Inferior rectus muscle
What are the two most common ocular exam findings of TAO?
Lid retraction and upper lid lag on down gaze
What condition is associated with tortuous, dilated epibulbar vessels that stop short of the limbus?
Carotid cavernous fistula
What are the causes of the 3 types of congenital anophthalmia?
Primary-> failure of optic vesicle to form Secondary–> Anterior neural tube defect. Consecutive -> Secondary degeneration of the optic vesicle
What causes congenital microphthalmos with orbital cyst?
Failure of choroidal fissure to close in utero
What is craniosynostosis?
Premature closure of one or more sutures of the bones of the skull (results in variety of skeletal deformities)
What is the most common cause of preseptal cellulitis in children?
Sinusitis
What is the most common type of organism causing preseptal and orbital cellulitis in children?
Gram-positive cocci
What is the most common organism of preseptal cellulitis resulting from trauma?
S. aureus
What condition is associated with non-septate, large branching hyphae that stain with H&E on biopsy of orbital infection?
Phycomycoses
What condition is associated with positive methylamine-silver nitrate stain showing branching hyphae of uniform width on biopsy of orbital infection
Think aspergillosis
What is the typical order of surgery in a patient with TAO and proptosis, ptosis, and strabismus?
Orbital decompression, strabismus surgery, then eyelid repair
What condition is associated with noncaseating collections of epithelioid histiocytes in a granulomatous pattern?
Sarcoidosis
What is the most common site of ocular involvement of sarcoidosis?
Lacrimal gland
What is the most common benign orbital tumor of adults?
Cavernous hemangioma (most common in middle-aged women)
What is the most common site of capillary hemangiomas?
Superonasal quadrant of the orbit and medial upper eyelid
What condition is associated with multiple, grape-like cystic lesions with fluid layering of serum and RBCs seen on MRI of orbital mass?
Lymphangioma
What is the treatment of choice of lymphangioma?
Deferment of surgery unless vision is affected
What type of AV fistula is associated with trauma?
Carotid cavernous fistula
What type of AV fistula is typically seen in older patients with HTN and atherosclerosis?
Dural cavernous fistula
What is the most cranial nerve affected by cavernous sinus thrombosis?
CN VI (due to vulnerable location within the middle of the cavernous sinus)
What condition is associated with diffuse enlargement of extraocular muscles and enlarged superior ophthalmic vein on CT scan of patient with proptosis and pain?
Dural cavernous fistula
What condition is associated with proptosis that increases when patient’s head is dependent or after Valsalava maneuver?
Orbital varix
What is the primary type of cell associated with a neurofibroma?
Schwann cells
What is the most common location of orbital meningioma?
Optic nerve sheath
What condition is associated with orbital mass associated with “tram-tracking” on plain film x-ray?
Optic nerve sheath meningioma
What condition is associated with orbital mass with biphasic pattern of nuclear palisading and myxoid areas?
Schwannoma
What is the most common primary orbital malignancy of childhood?
Rhabdomyosarcoma (average age of onset between 8-10 years)
What is the most common type of rhabdomyosarcoma?
Embryonal (typically associated with superonasal quadrant of orbit)
What is the treatment of choice for patients with localized ocular adenexal lymphoproliferative disease?
Radiation
What condition is associated with patient with lytic bone lesions and recurrent ocular inflammation?
Histiocytosis
What is the most common epithelial tumor of the lacrimal gland?
Pleomorphic adenoma
What is the most common malignant tumor of the lacrimal gland?
Adenoid cystic carcinoma
What is the most common epithelial tumor secondarily invading the orbit?
Squamous cell carcinoma
What type of leukemia is most likely to metastasize to the orbit?
ALL
What is the most malignant form of rhabdomyosarcoma?
Alveolar
What is the most common primary source of orbital metastasis in women?
Breast cancer
What is the most common source of orbital metastasis in men?
Bronchogenic carcinoma
What type of rhabdomyosarcoma has the best prognosis?
Pleomorphic
What is the most common orbital neoplasm?
Fibrous histiocytoma
Following extraocular muscles, what is the most common site of metastatic tumor to the orbit?
Bone marrow of the sphenoid bone
