Single-Fraction Radiation Therapy for Localized Cutaneous T-Cell Lymphoma.

PURPOSE: Mycosis fungoides is the most common type of cutaneous T-cell lymphoma (CTCL). Single-fraction radiation therapy has been used as a skin-targeted therapy to treat localized CTCL lesions. The objective of this study was to investigate the treatment outcomes associated with single-fraction radiation therapy for CTCL. METHODS AND MATERIALS: We retrospectively studied the outcomes among patients with CTCL treated with single-fraction radiation therapy at our institution between October 2013 and August 2022. Clinical response (complete response [CR], partial response [PR], or no response [NR]) and retreatment response were evaluated. RESULTS: A total of 242 lesions from 46 patients were analyzed, for an average of 5.3 lesions treated per patient. The majority of lesions presented with a plaque morphology (n = 145, 60.0%). All lesions were treated to a dose of 8 Gy in 1 fraction. Median follow-up was 24.6 months (range, 1-88 months). Of the 242 lesions, 36 (14.8%) had an initial PR or NR; all were retreated with the same regimen to the same site at a median interval of 8 weeks. Eighteen of the retreated lesions (50.0%) went on to have a CR. Thus, the overall CR rate for CTCL lesions was 92.6%. No recurrences were noted in the treated areas after achieving CR. CONCLUSIONS: Single-fraction radiation therapy to a dose of 8 Gy in 1 fraction to localized areas provided a high rate of complete and durable responses in the affected sites.

A Systematic Approach to the Cutaneous Lymphoid Infiltrates: A Clinical, Morphologic, and Immunophenotypic Evaluation.

CONTEXT.­: The evaluation of cutaneous lymphoid infiltrates, both neoplastic and inflammatory, occurs very frequently in routine dermatopathologic examination and consultation practices. The "tough" cutaneous lymphoid infiltrate is feared by many pathologists; skin biopsies are relatively small, whereas diagnostic possibilities are relatively broad. It is true that cutaneous lymphomas can be difficult to diagnose and that in many circumstances multiple biopsies are required to establish a correct diagnostic interpretation. As a reminder, one should understand that low-grade cutaneous lymphomas are indolent disorders that usually linger for decades and that therapy does not result in disease cure. It is also important to remember that in most circumstances, those patients will die from another process that is completely unrelated to a diagnosis of skin lymphoma (even in the absence of specific therapy). OBJECTIVE.­: To use a clinicopathologic, immunophenotypic, and molecular approach in the evaluation of common lymphocytic infiltrates. DATA SOURCES.­: An in-depth analysis of updated literature in the field of cutaneous lymphomas was done, with particular emphasis on updated terminology from the most recent World Health Organization classification of skin and hematologic tumors. CONCLUSIONS.­: A diagnosis of cutaneous lymphoid infiltrates can be adequately approached using a systematic scheme following the proposed ABCDE system. Overall, cutaneous T- and B-cell lymphomas are rare and "reactive" infiltrates are more common. Evaluation of lymphoid proliferations should start with a good sense of knowledge of the clinical presentation of the lesions, the clinical differential considerations, and a conscientious and appropriate use of immunohistochemistry and molecular tools.