CD1+S100+ – Friday Pop Quiz 01/22
A 24 month-old infant presents with red-brown, crusted papules with petechiae in a seborrheic distribution. A biopsy is done to confirm a diagnosis. Which histologic picture is most likely?
A. CD1-, S100- cells with reniform nuclei
B. Foamy histiocytes with Touton giant cells
C. CD1+, S100+ cells with reniform nuclei
D. Mixed cellular infiltrate in a “ball and claw� …
A 24 month-old infant presents with red-brown, crusted papules with petechiae in a seborrheic distribution. A biopsy is done to confirm a diagnosis. Which histologic picture is most likely?
A. CD1-, S100- cells with reniform nuclei
B. Foamy histiocytes with Touton giant cells
C. CD1+, S100+ cells with reniform nuclei
D. Mixed cellular infiltrate in a “ball and claw� … 
What is the diagnosis:
A. Alopecia areata
B. Trichotillomania
C. Androgenetic alopecia
D. Tinea capitis
E. Temporal triangular alopecia
To find out the correct answer and read the explanation, click here.
Brought to you by our brand partner Derm In-Review. A product of SanovaWorks.
… 
Histologically, this lesion shows plump, polygonal cells arranged in nests and fascicles with granular cytoplasm. Which immunohistochemical stain would be positive?
A. CD31
B. Synaptophysin
C. Factor XIIIa
D. S-100
E. CD34
To find out the correct answer and read the explanation, click here.
Brought to you by our brand partner Derm In-Review. A product of SanovaWorks.
… 
The pathology of this lesion demonstrates reticulate strands of the epidermis with clefting between the strands and the stroma. What is the diagnosis?
A. Eccrine syringofibroadenoma
B. Fibroepithelioma of Pinkus
C. Squamous cell carcinoma
D. Reticulate seborrheic keratosis
E. Tumor of the follicular infundibulim
To find out the correct answer and read the explanation, click her … 
This 48 year old woman tells you these lesions began as "acne bumps" on her legs. A biopsy reveals ulceration and a mixed inflammatory infiltrate, including neutrophils. A tissue culture for infectious organisms is negative. What is the most likely underlying systemic condition in this patient?
A. Celiac disease
B. Ovarian cancer
C. Chronic pancreatitis
D. IgA monoclonal gammopathy … 