Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles

Abstract

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is primarily a disease of older adults and is occasionally an incidental finding on skin biopsies accompanying epithelial neoplasms and insect bite reactions. In rare instances, however, it produces leukemic infiltrates showing clinical and histopathologic overlap with primary cutaneous B-cell lymphomas including primary cutaneous marginal zone lymphoma (PCMZL). Even less frequently, such findings serve as the initial disease manifestation. We present an exceptional case of a 61-year-old man with no past medical history whose clinical and histopathologic findings raised consideration for PCMZL with abnormal B-cells colonizing germinal center follicles; however, faint CD5 and CD23 co-expression raised the differential diagnosis of CLL/SLL. In light of an ambiguous clinical presentation with widely distributed papules and plaques, peripheral blood flow cytometry was also performed, revealing high count of CLLtype monoclonal B lymphocytosis. Subsequent workup revealed bone marrow involvement and mesenteric lymphadenopathy, supporting the diagnosis of SLL. Follicular colonization by SLL has not been previously reported. Our case underscores the importance of subtle immunophenotypic clues and correlations with clinical and radiologic findings in the workup of B-cell lymphomas presenting in the skin.

Follicular colonization in chronic lymphocytic leukemia/small lymphocytic lymphoma (comment on “Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles”)

“…We previously postulated that at least a subset of CLL/SLL is related to the follicle, most likely the outer mantle zone 4 . All of these findings further highlight the point made by LeBlanc et al 1 namely, the importance of ancillary studies in the accurate diagnosis and classification of lymphoid neoplasms whether in the skin or at other sites.…”

“…In this case report, the authors describe a case of systemic sarcoidosis with cutaneous involvement that demonstrated the rare finding of perineural granulomas on histopathology 1. The clinicopathologic mimicry of this sarcoidosis case to tuberculoid leprosy is particularly remarkable.…”

“…Follicular colonization in chronic lymphocytic leukemia/small lymphocytic lymphoma (comment on "Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles") I read with interest the report of "Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles" from LeBlanc et al 1 The authors indicate that follicular colonization in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has not previously been described.…”

“…We recently read with interest the article titled "Sarcoidosis with cutaneous perineural granulomas and neurological manifestations: A potential mimicker of leprosy." 1…”

“…I read with interest the report of “Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles” from LeBlanc et al 1 The authors indicate that follicular colonization in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has not previously been described. The authors’ point that CLL/SLL can mimic other lymphomas including marginal zone lymphomas is an important one; however, follicular colonization by SLL has been previously described and illustrated 2 .…”