Cutaneous involvement by a mantle cell lymphoma

Ana G. Lopes, Department of Dermatology and Venereology, Hospital de Braga, Braga, Portugal Teresa Pereira, Department of Dermatology and Venereology, Hospital de Braga, Braga, Portugal André Coelho, Department of Pathology, Centro Hospitalar Universitário de Santo António, Porto, Portugal Maria J. Guimarães, Department of Dermatology and Venereology, Hospital de Braga, Braga, Portugal Catarina Cerqueira, Service of Dermatology and Venereology, Hospital de Braga, Braga, Portugal Joana Gomes, Service of Dermatology and Venereology, Hospital de Braga, Braga, Portugal Celeste Brito, Service of Dermatology and Venereology, Hospital de Braga, Braga, Portugal

We describe the case of a 73-year-old female patient with priors of a mantle cell lymphoma (MCL), diagnosed 9 months ago, treated with chemotherapy, and currently with maintenance rituximab therapy, and a total knee replacement on the left leg 1 year ago. The patient presented to the Dermatology Department with patches on the left leg, with 3 months of evolution.

On examination, the patient presented infiltrated, confluent erythematous-violaceous patches and plaques, on the anterior surface of the left knee and leg, along the arthroplasty scar. No complaints associated. Blood work showed anaemia, neutropenia and an elevation of lactate dehydrogenase (LDH). A skin biopsy revealed occupation of the skin by a diffuse lymphoid proliferation, with intermediate-sized cells, with scarce cytoplasm, hyperchromatic nuclei and irregular borders. At immunohistochemistry, the cells were a cluster of differentiation (CD) 20+, CD5+, B-cell lymphoma 2 (Bcl-2) +, cyclin D1+ and CD3−. These findings are compatible with cutaneous involvement by MCL. The patient underwent radiotherapy on the left leg with regression of the lesions and is currently under chemotherapy. Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma (NHL). Cutaneous involvement is rare, secondary and means lymphoma dissemination. This case is also interesting for the site of skin involvement on a scar of knee replacement surgery.