Primary skin B-cell lymphoma manifested as a sole large nodular lesion

Primary cutaneous B-cell lymphoma (PCBCL) has only recently been recognized as a distinct clinicopathological entity which is characterized by an expansion of hematopoietic cells in the special microenvironment of the skin with no evidence of extracutaneous disease within the first six months after staging. PCBCLs represent heterogeneous lymphoproliferative conditions comprising 20-25 % of all cutaneous lymphomas.

A Caucasian, sixty five years old female patient with a 4-year history of asymptomatic nodular lesion in the lumbosacral region, firm-elastic to touch and painless, red-purple with smooth surface covered with multiple papules, was referred for the evaluation. Histopathological examination disclosed perivascular lymphocytic infiltrates in the upper part of the dermis, composed of medium-sized lymphocytes with light cytoplasm, especially in deeper dermis margining with fat tissue. Immunohistochemically, the tumor cells were CD20 positive, with a low admixture of CD45RO, CD3 and CD43-positive cells mostly at the periphery of the lesion. The tumor cells exhibited membrane or cytoplasmic expression of immunoglobulins with kappa light chains restriction.

Primary cutaneous marginal-zone B-cell lymphoma (PCMZL). The surgical excision was suggested. The patient is in a complete remission at the 3-year follow-up.

The primary B lymphoma is more frequently present then considered. The numerous lesions previously thought to be pseudolymphomas are genuine B lymphomas with a low grade malignancy. It is necessary to consider this condition in the differential diagnosis (Fig. 5, Ref. 12). Full Text (Free, PDF) www.bmj.sk.