Granulomatous dermatitis co-existing with cutaneous B cell lymphoma: Case report of an intriguing association

Abstract

A Granulomatous lesion in the skin is a common finding and cutaneous lymphoma, although less common, is not a rare entity. However few case reports exist of cutaneous granulomatous lesion harboring a lymphoma. We present a case of a 72-year-old male, with no known co morbidities presenting with painless erythematous papules and nodules over the forehead, trunk and limbs since 10 days. The skin biopsy from the lesion showed few granulomas along with giant cells and a diffuse monomorphic population of lymphoid cells in the dermis reaching up to the subcutaneous fat. The atypical morphology was further worked up with extensive panel of immunohistochemistry markers which favored the diagnosis of low-grade cutaneous B cell lymphoma. Patient was worked up for systemic lymphoma and PET CT revealed multiple enlarged homogenously enhancing lymph nodes. A cervical lymph node confirmed a nodal B-cell lymphoma. We present this case for its rarity and how evaluation of skin biopsy in this case provided useful clues towards diagnosis of a systemic lymphoma.