CD30+ T cell enriched primary cutaneous CD4+ small/medium sized pleomorphic T cell lymphoma: A distinct variant of indolent CD4+ T cell lymphoproliferative disease.

Primary cutaneous CD4+ small/medium sized pleomorphic T-cell lymphoma (SMPTCL) is unique among the peripheral T-cell lymphomas because of its indolent nature, typically presenting as a solitary nodule or plaque in the head and neck area of middle-aged and older adults. Recent studies have suggested a follicular helper cell origin for these lesions.

MATERIALS AND METHODS: A retrospective review was conducted on all cases of SMPTCL diagnosed between 2008 and 2017. The goal of our study was to better categorize the clinical, pathologic and molecular features of cases of SMPTCL showing a significant degree of CD30 neoplastic large cell infiltration.

RESULTS: Fifteen patients (10 male, 5 female) were encountered (age 33-86years at presentation). All lesions were solitary and the head and neck region was the most common area of involvement (7 cases). Surgical excision alone was performed in 6 cases and was supplemented with radiation in 5 cases. Disease recurrence did not occur. Spontaneous regression following biopsy was reported and two patients had a history compatible with lymphomatoid papulosis. All cases showed pathologic features characteristic of SMPTCL. Additionally, there were many larger CD30+ T-cells occupying 15-30% of the infiltrate. Monoclonality was demonstrated in 5 of 10 cases in which clonality studies were performed.

CONCLUSION: CD30 positivity amidst large neoplastic T-cells is not uncommon in SMPTCL. The extent of CD30 positivity in SMPTCL needs to be defined further along with its association with other forms of CD30+ lymphoproliferative disease including its potential categorization as a form of endogenous CD30+ lymphoproliferative disease.