57 year-old woman with a one-year history of an eruption on arms and legs
Her skin lesions, mostly on the arms and legs, are few and scattered. They are erythematous, slightly scaly, ill-defined plaques with irregular borders.
Photomicrographs graphs and interpretations courtesy of Dr. Deon Wolpowitz
Boston University, Department of Dermatology
The specimen exhibits superficial and deep, nodular well-formed collections of epithelioid histiocytes and multinucleated giant cells forming granulomas with sparse to mild lymphocytic rims and a moderate superficial and mid perivascular lymphocytic infiltrate. The histologic differential diagnosis includes sarcoidosis, a foreign body reaction, and infectious etiologies including mycobacterial infections. Polariscopic examination is negative. Fite stain is negative for mycobacteria. PAS stain is negative for fungal organisms.