Track

Case Reports

Abstract

An 84-year-old female with complex medical history presented with extensive fixed pink plaques on her trunk and extremities. Dermatopathology revealed a superficial to deep dermal sheet-like infiltrate of medium to large abnormal lymphoid cells, exhibiting a contradictory immunophenotypic profile. The lesional cells stained positive for T-cell markers CD3 and CD5 but were negative for CD4 and CD8. These cells were negative for B-cell markers CD19 and PAX5 but were unexpectedly positive for CD20. This immunophenotypic profile raised the differential of both a T-cell and a B-cell neoplasm. Two weeks after initial biopsy, the patient presented with sepsis, acute renal failure, and shock. Her physical exam was now notable for red indurated plaques and tumors that had drastically progressed to involve her face and more body surface area. Re-biopsy revealed an expanded abnormal lymphocytic infiltrate involving the entire dermis and extending to the subcutaneous tissue, with an immunophenotypic profile identical to the initial biopsy. T-cell receptor (TCR) gamma gene rearrangement was positive, confirming T-cell origin, and flow cytometry showed evidence of systemic involvement by the neoplastic cells. The patient received doxorubicin but unfortunately passed away two weeks after admission due to complications of sepsis. This rare case highlights the unusual occurrence of B-cell marker CD20 expression, which has been reported in 18% of primary cutaneous peripheral T- cell lymphomas, NOS, often associated with an aggressive clinical course. Rituximab has been administered as a chemotherapeutic agent in few cases with aberrant expression of CD20.