Primary cutaneous follicle center lymphoma of the breast: Management of an exceedingly rare malignancy.

Primary cutaneous follicle center lymphoma (PCFCL) is defined as a low-grade B-cell non- Hodgkins lymphoma, which primarily occurs and remains confined to the skin, without evidence of extracutaneous or systemic involvement at the time of diagnosis. PCFCL affecting the breast skin is an exceedingly rare entity with only two cases reported in the English literature. We present a case of PCFCL affecting the periareolar breast skin and review the relevant literature. Our patient was a 64-year-old female who presented with an erythematous plaque in the periareolar region of the left breast. The diagnosis of PCFCL was confirmed by a biopsy performed with a seven-month delay, as the tumor had been initially misdiagnosed as a benign lesion. The patient was successfully treated with local radiation therapy. PCFCL is an indolent lymphoma associated with an excellent prognosis. For localized lesions, skin-directed therapies mainly consisting of radiation therapy or complete surgical excision are curative therapeutic approaches, while systemic chemotherapy should be reserved for patients with extensive disease. This case highlights the need to consider PCFCL as an important differential diagnosis in patients presenting with non-resolving erythematous breast skin lesions. A timely biopsy should be obtained to avoid delays in the initiation of appropriate treatment.