Atypical clinical presentation of primary and secondary cutaneous follicle center lymphoma (FCL) on the head characterized by macular lesions.

Abstract

Primary cutaneous follicle center lymphoma (pcFCL) usually presents with reddish nodules, plaques, and tumors on the head and neck or the back. We sought to describe a peculiar clinical presentation of pcFCL and secondary cutaneous follicle center lymphoma (FCL). We report a series of 13 patients (7 male and 6 female; median age 58 years, mean age 58.2 years, age range 26-83 years) with either pcFCL (11 patients) or secondary cutaneous FCL (2 patients) presenting with lesions on the head deviating from the classic clinical manifestations characterized by plaques and tumors. All patients presented clinically with diffuse, ill-defined, partly hypochromic, partly erythematous macules or with inconspicuous lesions located predominantly on the scalp and forehead. Dimension ranged between 4 to 5 cm² and greater than 30 cm². The initial diagnosis was never cutaneous lymphoma, and all patients received various diagnoses including rosacea, alopecia, erysipelas, discoid lupus erythematosus, angiosarcoma, Borrelia infection, or sarcoidosis. Histologic examination confirmed the diagnosis of FCL in all patients. Small number of cases and retrospective study design are limitations. This clinical presentation of both pcFCL and secondary cutaneous FCL is unusual and represents a pitfall in the clinical diagnosis. Dermatologists should be aware of this clinical variant of FCL to establish a timely diagnosis and treat patients properly.