Abstract

Leukemias may present with variable cutaneous manifestations, including leukemia cutis. They may also present with non-specific reactive cutaneous lesions including neutrophilic dermatoses, reactive erythema, vasculitis, panniculitis, urticaria, and erythema multiforme, among others. Monocytic leukemias in particular have been reported in association with cutaneous myeloid sarcoma, vasculitis, Sweet’s syndrome and cutis verticis gyrata. We present the case of a 72-year-old female who presented with an acute pruritic eruption on the trunk and upper and lower extremities. On examination, there were scattered pink to violaceous eroded and crusted papules on the trunk, upper extremities, and left thigh. Clinical impression was pityriasis lichenoides et varioliformis acuta (PLEVA). Notably, patient also described history of B-symptoms including chronic fatigue. Punch biopsies of an early and late lesion were taken, demonstrating superficial and deep perivascular, periadnexal inflammation with vacuolar interface dermatitis, neutrophilic crust, dermal erythrocytes, and cytophagic histiocytosis. Presence of cytophagic histiocytosis prompted further work-up for associated malignancy. Flow cytometry detected a population of myeloblasts (2%) and an expanded population of CD33+ monocytic cells (53%). A diagnosis of acute myeloid leukemia with monocytic differentiation was made. Our patient’s clinical lesions and histological findings mimicked PLEVA aside from presence of macrophages containing erythrocytes, lymphocytes, and karyorrhectic debris, known as ‘bean-bag’ cells. While previously reported in association with viral exanthems or subcutaneous lymphomas of primarily T-cell and rarely B-cell lineage, our case describes cytophagic histiocytosis in cutaneous lesions associated with a leukemia of myeloid lineage. We posit that presence of cytophagic histiocytosis should prompt work up for a broad differential including underlying myeloid malignancy.

Financial Disclosure:
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