Occurence of Cutaneous Marginal Zone B-Cell Lymphoma Post Breast Cancer Chemotherapy: A Case Report

Primary cutaneous marginal zone B-cell lymphomas (PCMZLs) are classified as low-grade as they run an indolent course. They are histologically characterized through non-epidermotropic nodular or diffuse infiltrates consisting of small or medium heterogeneous atypical lymphoid cells. In the past few years, chemotherapy has increased the survival rate of breast cancer patients. However, the adverse effects of treatment, such as leukemia, have also been shown to emerge gradually. Additionally, cases of occurrence of non-Hodgkin lymphoma (NHL) post chemotherapy have also been reported. A 48-year-old female patient was presented with a violaceous nodule on her left thigh. Around 15 months ago, she completed breast cancer chemotherapy. Eight months later, a skin lesion appeared. Histological findings revealed dense and nodular lymphocyte infiltration. Immunohistochemical staining was positive for CD20 and BCL2. Clinical and histological examination of the lesions confirmed PCMZL. After systemic evaluation, lymphoma was found to be limited to the skin, and thus, she underwent complete excision of the lesion. At the first month follow-up, there was a recurrent lesion on the right wrist, which was excised successfully. However, recurrences occurred again in the calf and forearm in the following five and two months, respectively. These lesions were also confirmed with PCMZL using biopsy. We assume that this case is related to chemotherapy as it was presented and recurred abruptly post chemotherapy. Additionally, there are several reported cases of NHL post breast cancer chemotherapy. However, this is the first case report of PCMZL associated with chemotherapy.