Primary cutaneous diffuse large B‑cell lymphoma of the scalp: A case report and brief review of the literature

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of extranodal lymphoid neoplasms confined to the skin at diagnosis. Primary cutaneous diffuse large B‑cell lymphoma, not otherwise specified (PCDLBCL‑NOS), is a rare and aggressive subtype, and the involvement of the scalp is exceptionally uncommon. The present study describes the case of a 45‑year‑old female patient with PCDLBCL‑NOS presenting with atypical alopecic scalp lesions. The patient presented with a 4‑month history of localized scalp hair loss associated with mild erythema and pruritus, without systemic symptoms. A histopathological examination of a punch biopsy revealed a dense dermal and perifollicular infiltrate of atypical large lymphoid cells. Immunohistochemistry demonstrated positivity for CD20, CD10, CD79a and BCL‑2, with negativity for CD3 and MUM1. Comprehensive imaging revealed no extracutaneous disease, and a diagnosis of stage IA(E) PCDLBCL‑NOS was established. The patient was treated with six cycles of R‑CHOP chemotherapy, achieving complete clinical and radiological remission at the 6‑month follow‑up. Subsequently, the patient developed pancytopenia and was diagnosed with B‑cell acute lymphoblastic leukemia. Despite the initiation of HYPER‑CVAD chemotherapy, her course was complicated by severe neutropenic sepsis; thus, the patient succumbed. In addition, a review of the literature identified only five previously reported cases of scalp PCDLBCL, all occurring in male patients. The case described herein highlights an unusual clinical presentation, underscores the importance of considering lymphoma in the differential diagnosis of atypical alopecic scalp lesions, and illustrates both the potential for initial therapeutic response and the risk of severe hematologic complications.