Primary cutaneous follicle center lymphoma with diffuse CD30 expression: A report of 4 cases of a rare variant

Background CD30 is expressed in aggressive and Epstein–Barr virus–associated forms of B-cell non-Hodgkin lymphomas, but is rarely expressed by the majority of tumor cells in primary cutaneous B-cell lymphomas (CBCLs). The expression of CD30 in CBCLs may be at risk for misinterpretation as an unequivocal indicator of a highly aggressive form of the disease. Objective We report 4 cases of low malignant primary cutaneous follicle center lymphoma (PCFCL) with diffuse and strong expression of CD30 by the majority of neoplastic cells. Results The patients included 3 men and 1 woman with tumors on the scalp (3 patients) and chest wall (1 patient). The histologic examinations revealed a mixed, diffuse, and follicular growth pattern with CD20+ , bcl-6+ , and bcl-2− tumor cells. Seventy percent to 90% of the tumor cells expressed CD30. Clonal rearrangement of immunoglobulin heavy chain genes was found in 1 of 4 cases. None of the 3 cases yielded positivity for Epstein–Barr virus RNA. Limitations The study is limited by the small number of patients. Conclusions This rare variant of CD30+ PCFCL needs be distinguished from CD30+ aggressive B-cell lymphomas. CD30 in this variant of CBCLs may serve as a therapeutic target for anti-CD30 antibody–based strategies.