Intriguing Nodules Mimicking as Leprosy: An Interesting Case Report

The differential diagnosis of disseminated infiltrated cutaneous nodules includes a plethora of disorders ranging from the more frequently encountered infective and granulomatous conditions to the obscure ones with proliferative and malignant origin. Histiocytosis can be divided into those involving dendritic cells and those involving the macrophage–monocyte lineage. Sinus histiocytosis with massive lymphadenopathy (Rosai–Dorfman disease) is a rare benign disease of unknown etiology. It is imperative to distinguish this from lymphoma and other types of histiocytosis because of the vast differences in management strategies and prognosis. We hereby report an elderly woman who presented with erythematous infiltrated nodules, previously diagnosed and treated unsuccessfully as leprosy. However, her clinical examination revealed cervical and axillary lymphadenopathy which led us to the final diagnosis of Rosai–Dorfman disease on the basis of emperipolesis with lymphohemophagocytosis on histopathology with positive staining for CD 68, S100, and negative CD 1a staining on immunohistochemistry.