Primary Cutaneous Anaplastic Large-Cell Lymphoma With Aberrant CD20 Expression: Case Report and Review of the Literature

Abstract

Cutaneous CD20 + T-cell lymphomas are exceedingly rare. Differentiating cases of T-cell lymphoma with aberrant expression of the B-cell marker CD20 from B-cell lymphoma may be associated with misdiagnosis or delays in diagnosis. We report, to the authors' knowledge, the first case of CD20 + primary cutaneous anaplastic large-cell lymphoma and review the literature to characterize published cases of CD20 + cutaneous T-cell lymphoma (n = 40). There is no accepted explanation for this phenomenon; however, it is suspected that these cases may be due to neoplastic transformation of CD20 + T cells or that CD20 may represent a T-cell activation marker. Expression of CD20 may have clinical significance in prognostication and consideration of treatment options with anti-CD20 therapies such as rituximab.

A Rare Case of Primary Cutaneous Gamma-Delta T-cell Lymphoma with Aberrant B-cell Marker Expression

“…Aberrant B-cell marker expression has been rarely described in some T-cell lymphomas, including hepatosplenic T-cell lymphoma, primary cutaneous CD4 + small/medium T-cell lymphoproliferative disorder, systemic and extranodal NK/T-cell lymphomas, adult T-cell leukemia/lymphoma, angioimmunoblastic T-cell lymphoma, mycosis fungoides, cutaneous peripheral T-cell lymphoma not otherwise specified, and cutaneous and systemic anaplastic large-cell lymphoma. 7–10,12 In addition, rare instances of γδ T-cell lymphomas with aberrant B-cell marker expression have been reported, however, to the best of our knowledge not with a proper diagnosis of PCGDTL. 10–12,15 Our case lacked CD20 expression.…”

“…7–10,12 In addition, rare instances of γδ T-cell lymphomas with aberrant B-cell marker expression have been reported, however, to the best of our knowledge not with a proper diagnosis of PCGDTL. 10–12,15 Our case lacked CD20 expression.…”

“…11 Finally, although driver mutations have been described, translocations are extraordinarily rare. 12,18 Understanding the entire immunophenotypic spectrum of the disease can be very helpful, including the aberrant B-cell markers described in this unusual case presentation.…”