(VIRTUAL) THE MISLEADING SYPHILIS: TWO CASES MASQUERADING AS LYMPHOMAS

Track
Case Reports
Abstract

Syphilis, known for its notorious mimicry in both clinical and histopathological presentations, is often mistaken for various types of cutaneous lymphoma. We present two cases where secondary syphilis was misinterpreted as primary cutaneous marginal zone lymphoma (MZL) and CD8-positive cytotoxic cutaneous lymphoma. Herein, a 52-year-old female presented with generalized erythematous plaques for three months. Biopsy revealed a dense dermal perivascular lymphocytic infiltrate with numerous plasma cells, composed of a mixed population of CD3+T-cells and CD20+ B-cells with a subset of B-cells being positive for BCL2 and BCL6. Kappa and lambda by in situ hybridization showed a predominance of kappa-positive plasma cells, and the diagnostic suspicion for primary cutaneous MZL was rendered. Subsequent spirochete immunohistochemical study highlighted numerous spirochetes, followed by positive RPR (rapid plasma reagin) and a negative flow cytometry result confirming the reactive nature of the dermal infiltrate. Second case, a 60-year-old male presented with severe gastritis and esophageal candidiasis followed by disseminated eruption clinically suspicious for drug eruption after antifungal therapy. Biopsy revealed interface changes and a perivascular lymphocytic infiltrate composed of focally cytologically atypical CD3+, CD8+, TCRbetaF1+ T-cells with retained CD7 expression and immunoreactivity for TIA-1 and granzyme B. Further bone marrow biopsy and flow cytometry were unremarkable. Additional spirochete immunohistochemical study highlighted numerous spirochetes, confirming a diagnosis of syphilis with reactive CD8-positive cytotoxic lymphoid infiltrate. These cases underscore the importance of maintaining a high index of suspicion for syphilis when initially diagnosing cutaneous lymphoproliferative disorders to avoid misdiagnosis and unnecessary invasive procedures.

Published in: ASDP 61st Annual Meeting

Publisher: The American Society of Dermatopathology
Date of Conference: November 4-10, 2024