Primary cutaneous small- to medium-sized CD4 pleomorphic T-cell lymphoma: A retrospective case series and review of the provisional cutaneous lymphoma category

Background and Objective: Primary cutaneous small- to medium-sized CD4+ pleomorphic T-cell lymphoma(PCSM-TCL) is a rare and provisional subcategory of cutaneous T-cell lymphoma, associated with afavorable prognosis. We present five cases of PCSM-TCL and review the literature to address questionssurrounding its diagnosis and treatment.Methods: A retrospective review was conducted of 353 patients with non-mycosis fungoides cutaneouslymphomas evaluated at the M.D. Anderson Cancer Center Cutaneous Lymphoma Clinic over 10 years.A retrospective search of the English literature using PubMed was conducted to identify additional cases.Results: Only five patients had a diagnosis of PCSM-TCL. Three patients had unique multifocal presentationsthat responded well to topical therapy or excision. One patient with localized disease initiallytreated with radiation therapy had an aggressive relapse requiring systemic therapy. One patient had anisolated nodule that fully resolved with excision. The review of the English literature found 232 additionalcases. The presentation of PCSM-TCL was heterogeneous and included solitary/localized papules, nodules,plaques, and tumors. Multiple differential diagnoses were considered and PCSM-TCL diagnosis was basedon histopathologic features and clinical correlation. Treatment of solitary/localized lesions included excisionor radiation therapy. Multifocal lesions were uncommon and associated with an aggressive course requiringsystemic chemotherapy.Conclusions: The heterogeneous presentation, variable histologic overlap with other lymphoproliferativedisorders, and uncertain prognosis of PCSM-TCL creates diagnostic and management dilemmas forclinicians. For treatment, a distinction should be made between indolent and aggressive subtypes. Furtherinvestigation is needed to determine if PCSM-TCL is indeed a distinct lymphoma category and, additionally,if aggressive subtypes should remain part of the same diagnostic category.