Mantle cell lymphoma with skin involvement: Case report of a rare manifestation in a patient with initial diagnosis of chronic lymphocytic leukemia

Mantle cell lymphoma is a rare subtype of B-cell non-Hodgkin's lymphoma, which mainly affects males. It has a variable clinical presentation, with a course ranging from indolent cases that do not require treatment for years to very aggressive cases. Skin involvement is a rare event. Although most patients have disease in stage III or IV at diagnosis, they generally present with good functional status. In immunohistochemistry, CD5 is commonly expressed, a feature it shares with chronic lymphocytic leukemia. Cyclin D1 and SOX11 expression are present in almost all cases. Treatment depends on multiple factors such as age, frailty, comorbidities, disease stage, symptoms and morphological characteristics. We present the case of a male patient initially diagnosed with chronic lymphocytic leukemia who was started on treatment with ibrutinib. A biopsy of the right earlobe was subsequently performed, which documented secondary skin involvement due to a classic histological variant of mantle cell lymphoma. The patient was treated with chemotherapy between March and July 2022, with positron emission tomography at the end of the proposed cycles with complete metabolic response, so maintenance treatment with rituximab was performed and subsequently consolidated with an autologous bone marrow transplant. To date, the patient is in remission of the disease.