Primary Cutaneous Spindle Cell B-Cell Follicle Center Lymphoma Presenting as Long-Standing Plaque of Cicatricial Alopecia: A Case Report With a Comprehensive Review of the Literature.

Primary cutaneous spindle B-cell lymphoma is an uncommon subtype of cutaneous lymphoma characterized by a distinct spindled cytology of neoplastic B cells. Despite sharing clinical, histopathological, and phenotypical similarities with primary cutaneous follicle center lymphoma, an indolent form of B-cell lymphoma, it also exhibits certain features akin to primary cutaneous diffuse large B-cell lymphoma. Notably, in rare instances, a more aggressive clinical course has been observed. This report details a rare case of primary cutaneous spindle cell B-cell follicle center lymphoma, manifested as a prolonged solitary plaque of cicatricial alopecia. In addition, we provide a comprehensive review of existing cases documented in the literature.