Primary cutaneous T-cell lymphomas other than mycosis fungoides and Sézary syndrome. Part I: Clinical and histologic features and diagnosis

Abstract

Primary cutaneous T-cell lymphomas (CTCLs) are defined as lymphomas with a T-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation. CTCLs other than mycosis fungoides and Sézary syndrome (SS) account for approximately one third of CTCLs and encompass a heterogenous group of non-Hodgkin lymphomas, ranging from indolent lymphoproliferative disorders to aggressive malignancies with a poor prognosis. The spectrum of CTCLs continues to broaden as new provisional entities are classified. Given the morphologic and histologic overlap among CTCLs and other diagnoses, a thorough clinical history, physical evaluation, and clinicopathologic correlation are essential in the work up and diagnosis of these rare entities. This article will summarize the epidemiologic, clinical, pathologic, and diagnostic features of CTCLs other than mycosis fungoides and SS.

Keywords: CD30(+) lymphoproliferative disorders; Sézary syndrome; T-cell lymphoma; adult T-cell leukemia; adult T-cell lymphoma; angioimmunoblastic T-cell lymphoma; cutaneous T-cell lymphoma; cytotoxic primary cutaneous anaplastic large cell lymphoma; extranodal NK/T-cell lymphoma; lymphomatoid papulosis; mycosis fungoides; nasal type; not otherwise specified; peripheral T-cell lymphoma; primary cutaneous CD4(+) small/medium T-cell lymphoproliferative disorder; primary cutaneous CD8(+) aggressive epidermotropic cytotoxic T-cell lymphoma; primary cutaneous acral CD8(+) T-cell lymphoma; primary cutaneous gamma-delta T-cell lymphoma; subcutaneous panniculitis-like T-cell lymphoma.