Granulomatous Dermatitis With Dense Plasma Cells: A Diagnostic Clue for Cutaneous Leishmaniasis.

Overview

Cutaneous leishmaniasis presents with variable clinical and histopathological features, often complicating diagnosis. Acute lesions with high parasite burden are typically easier to identify, but chronic lesions with low organism load can be more challenging, particularly when leishmaniasis is not clinically suspected. Although granulomatous and lymphoplasmacytic infiltrates are well documented, our study underscores the diagnostic relevance of a plasma cell-rich, loosely organized granulomatous pattern. Observed in both Old and New World infections, this pattern may serve as a key histologic clue when organisms are sparse and confirmatory testing is limited or delayed. Recognizing it can prompt appropriate ancillary testing, guide treatment decisions, and reduce diagnostic delays, especially in low parasite burden cases or in settings where leishmaniasis is not routinely considered.