Primary Cutaneous T-cell Lymphoma With Aberrant CD-20 Expression

May 2015 | Volume 14 | Issue 5 | Case Reports | 515 | Copyright © May 2015

Chante Karimkhani BA,a Cristina McLaughlin MD,b and Christopher Smith MDc

aColumbia University College of Physicians and Surgeons, New York, NY
bUniPath LLC, Denver, CO
cFlatirons Dermatology, Broomfield, CO

Abstract
IMPORTANCE: Primary cutaneous T-cell lymphoma with aberrant expression of cluster of differentiation (CD) 20 is an exceedingly rare manifestation of cutaneous T-cell lymphoma that is easily misdiagnosed as B-cell lymphoma. The significance and prognostic implications of T-cell neoplasms demonstrating the classic CD20 B-cell marker have yet to be elucidated.
OBSERVATIONS: We present a case of primary cutaneous T-cell lymphoma with aberrant CD20 expression in a 97-year-old male who presented with a 2-year history of pruritic plaques and nodules covering his body. Nodule biopsy demonstrated a dense, atypical dermal T-lymphocytic infiltrate consisting of predominantly large cells exhibiting classic T-cell markers (CD4 and CD3) along with aberrant expression of the B-cell marker CD20 (expressed in late pro-B to mature B cells).
CONCLUSIONS: The patient was tentatively diagnosed with primary cutaneous CD30-negative large T-cell lymphoma with aberrant CD20 co-expression, pending workup to exclude systemic lymphoma with cutaneous involvement. He unfortunately passed away 4 days after the initial dermatologic presentation.
RELEVANCE: The prognostic implications of CD20-positive T-cell lymphoma require further exploration, along with the potential role of CD20 antibody in treatment of this rare malignancy.

J Drugs Dermatol. 2015;14(5):515-516.

CASE REPORT

Primary cutaneous T-cell lymphoma with aberrant expression of cluster of differentiation (CD) 20 is an exceedingly rare manifestation of cutaneous T-cell lymphoma that is easily misdiagnosed as B-cell lymphoma.1,2,3 Additionally, while cutaneous B-cell lymphomas are associated with a favorable prognosis, the significance and prognostic implications of Tcell neoplasms demonstrating the classic CD20 B-cell marker have yet to be elucidated.4 One leading hypothesis postulates that the neoplasm may arise from malignant transformation of a small subset of normal resident CD20+ T cells (3% of circulating T cells), while others speculate that CD20 expression by T cells is truly an aberrant finding of T-cell activation.5,6