Atypical Chromoblastomycosis Presenting as a Large Lesion of the Hand and Forearm Resembling Lupus Vulgaris: A Clinicopathological Case Report.

Chromoblastomycosis is a chronic implantation mycosis caused by melanized fungi, typically affecting rural male workers following traumatic inoculation with soil or vegetative matter. It most commonly involves the lower limbs and is often diagnosed late because of its indolent course and its resemblance to other chronic verrucous dermatoses. We report the case of a 54-year-old man who presented with a 10-year history of a slowly progressive lesion involving the right hand and distal forearm. The lesion was associated with intermittent pruritus and occasional serous discharge. Clinically, the large plaque over the hand and forearm resembled lupus vulgaris, creating diagnostic difficulty. Histopathology, however, demonstrated characteristic sclerotic bodies, establishing the diagnosis of chromoblastomycosis. The case is notable for the unusual upper-limb involvement, large lesion size, and clinical resemblance to lupus vulgaris. This report highlights the importance of considering chromoblastomycosis in the differential diagnosis of long-standing plaques over exposed upper extremities.