Pathology-Eye w:some Nose & Ear Flashcards
What is the difference between lepromatous and tuberculoid leprosy?
Lepromatous: poor helper cell response. Schwann cell invasion causes demyelination in a “sock and glove” distribution. Tuberculoid: cell-mediated helper cell response forming granulomas. Asymmetric, dry, scaly lesions.
A patient presents to the clinic with deformities in both hands and loss of sensation in his feet. Biopsy of the foot lesion is shown below. What type of leprosy does this patient have?
Note the presence of many organisms packed in foamy macrophages (Lepra cells). This is indicative of lepromatous leprosy because the many cells indicate a weak Th1 immune response as opposed to the strong cell-mediated secretion of Il-2 and IF-gamma w/absence of lepra cells in tuberculoid leprosy.
Most common peripheral nerve tumor. Common causes.
Schwannoma. Can be caused by nerve compression or mutation of NF2 gene on chromosome 22 that causes loss of merlin (cells will hyper proliferate w/loss of merlin).
A 62 year old male presents with right-sided hearing loss, instability, vertigo and persistent ringing in his ears. Biopsy of his ear is shown below. What is your diagnosis?
Note the hypercellular (Antoni A in left image) and hypocellular (Antoni B in right image) areas. Also notice the Verocay bodies (palisading of spindle cells in the Antoni A area). This patient has an acoustic Schwannoma.
A 31 year old female presents with protruding eyeballs (protosis) and dry eye. She also has corneal clouding. Physical exam reveals edematous shins. What is your diagnosis?
She has Grave’s disease. In this disease muscle bodies accumulate extracellular matrix, proteins and fibrosis, causing them to swell up. Note that tendons are spared.
How does the orbit get infected?
Ethmoidal sinusitis extends to the orbit and cause orbital cellulitis. Mucormycosis (rapidly progressing fungal infection in DKA or immunosuppression).
A patient presents with enlarged eyelids from a blocked sebaceous gland. It got better with ward compress. What is your diagnosis?
Chalazion
Chronic inflammation at the eyelid margin
Blephatitis
What are common neoplasms seen in the eyelid?
1) Basal cell carcinoma on the lower eye lid from UV exposure #2) Sebaceous carcinoma #3) Squamous cell carcinoma.
What is the worst case scenario for this patient?
This patient has a uveal nevus on the iris. Atypical nevi can develop into melanomas, note that optic melanomas lack the radial growth phase that dermatologic melanomas have.
Common chronic diseases that present with uveitis.
Juvenile rheumatoid arthritis, pneumocystis jerivicii, sarcoid and sympathetic opthalmia.
A 22 year old male had a traumatic eye injury. Two weeks later he complains of bilateral floating spots, uveitis and photophobia. Biopsy of the uninjured eye is shown below. What is your diagnosis?
Sympathetic opthalmia. This is caused by retinal antigens in the injured eye initiating a delayed hypersensitivity reaction to both eyes. Note the granulomatous inflammation.
What is the most common source of intra-ocular neoplasm?
Metastasis. The most common primary neoplasm is melanoma.
When do you decide if you want to biopsy and treat the lesion seen below?
If it’s diameter grows, NOT DEPTH. Benign nevi are common in 10% of the population and very few progress to melanoma. If the intra-ocular spot grows, it is likely melanoma.
A patient presents to the clinic complaining of weight gain. You exam his stomach and note that he has ascites. Labs reveal liver failure and imaging reveals a tumor in the liver. What eye lesion could have caused this?
Uveal melanomas spread hematogenously, not through the lymphatics like dermatologic melanomas do. The first place they usually spread to is the liver and can have very late metastasis decades later.
A patient presents with difficulty seeing in one eye. Further exam reveals melanoma in the uvea. Biopsy reveals elongated neural-looking cells. What is your diagnosis?
Spindle cell melanoma. Epitheliod melanomas have cells with lots of cytoplasm, prominent cherry-red nucleoli and sheet-like congregation of cells.
Which patient with uveal melanoma has the better prognosis?
The bottom one. The top is spindle cell melanoma and the bottom is epitheliod melanoma. Epitheliod melanoma is worse.
Would you rather have a uveal melanoma on the iris or in the uvea?
Iris. Melanomas in the choroid or ciliary body tend to be more aggressive.
What conditions are associated with uveal melanoma?
Monosomy 3, Trisomy 8 and Vasculogenic Mimicry (PAS +, vascular channels surrounding the melanoma shown below)
How do you treat uveal melanoma?
Enucleation or radiation. You must treat quickly because hematogenous spread is fatal.
A patient presents to the clinic with vision problems. Physical exam findings are shown below. Histologically, where in the eye does this patient have problems?
In the nerve fiber layer. This is where arteriolosclerosis affects the retinal blood vessels. Note that the vessel is thinner, not as red and is compressing the vein in the fundoscopic exam.
What type of tissue damage can be caused in the retina from hypertension?
Cotton wool spots. Small infarcts and degeneration in the superficial nerve fiber layer.
What happens in the preproliferative phase of diabetic retinopathy?
1st, the basement membrane of retinal vessels thickens, causing decreased perfusion and macular edema. VEGF-induced angiogenesis of abnormal vessels in retina follows. The nerve fiber and ganglion layer will degenerate as seen below.
What happens in the proliferative phase of diabetic retinopathy?
Abundant new vessels sprout in the back of the retina
A 77 year old woman presents with blurred central vision. What are risk factors for this condition?
Risk factors for macular degeneration are: old age, female, obesity, smoking & CFH (complement factor H)
What is pathological progression of macular degeneration?
Blood vessels in the choroid proliferate and go through the Bruch membrane, affecting the retinal pigment epithelium (RPE). Disturbance of the macula causes atrophy of overlying photoreceptors in retina and blindness.
Most common primary intra-ocular tumor in kids (age 5 or younger)? What is its origin?
Retinoblastoma (note leukokoria in left eye). 40% of these are caused by mutation of one RB allele. Mutation prevents RB from regulating the G1-S phase stop and cells replicate very rapidly.
A mother brings her 3 year old boy in because of an abnormal appearance to his left eye. They eye is taken out and shown below. What would you expect the histology of this tumor to look like?
Retinoblastoma is a small round blue cell tumor. Retinoblastoma tends to grow around blood vessels, however, the tumor proliferates so quickly that cells further from blood vessels are necrotic. Cells also form Flexner-Wintersteiner rosettes (blue cells around a cleared space).
