Ibrahim Elsayed, Dai Julia, Lenskaya Volha, Torres-Cabala Carlos A, Cho Woo Cheal
Department of Anatomical Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX; and.
Department of Dermatology, The University of Texas MD Anderson Cancer Center, Houston, TX.
Am J Dermatopathol. 2025 Jun 17;47(8):634-637. doi: 10.1097/DAD.0000000000002999.
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous T-cell lymphoma with adipotropism characterized by infiltration of CD8 + T cells exhibiting a cytotoxic and αβ phenotype. Although SPTCL is typically indolent, distinguishing it from more aggressive cutaneous lymphomas such as primary cutaneous γδ T-cell lymphoma is critical for accurate prognosis. We present a case of SPTCL in a 26-year-old Asian woman with a history of hemophagocytic lymphohistiocytosis, who presented with nonulcerated, erythematous patches and hyperpigmented nodules on her extremities and trunk persisting for 5 months. Biopsy specimens revealed an atypical lymphoid infiltrate with prominent adipotropism, predominantly comprising atypical medium-sized lymphocytes rimming the adipocytes. Immunophenotypically, the lesional lymphocytes were CD3+/CD4-/CD8+/CD7+ T cells expressing TIA1, granzyme B, and TCR βF1, while lacking CD30 and Epstein-Barr virus-encoded small RNA expression. Intriguingly, there was a markedly increased density of T cells expressing TCR δ, some surrounding adipocytes and appearing neoplastic. CD123 failed to reveal aggregates of plasmacytoid dendritic cells. Molecular analysis revealed monoclonal TCR β and γ gene rearrangements. Despite the elevated γδ T-cell population (20%-50% of the T cells), the overall clinical, histopathologic, and molecular findings, along with the absence of rapid disease progression, supported a diagnosis of SPTCL. Although increased densities of reactive γδ T-cells or γδ T-cell phenotypes in neoplastic cells are observed in various benign and malignant dermatologic conditions, the literature on this phenomenon-particularly in SPTCL-remains scarce. Our case highlights the importance of recognizing an increased γδ T-cell population in SPTCL to prevent misdiagnosis as a more aggressive lymphoma such as primary cutaneous γδ T-cell lymphoma, underscoring the need for thorough clinicopathologic correlation.
皮下脂膜炎样T细胞淋巴瘤（SPTCL）是一种罕见的原发性皮肤T细胞淋巴瘤，具有亲脂性，其特征为CD8 + T细胞浸润，表现出细胞毒性和αβ表型。尽管SPTCL通常呈惰性，但将其与更具侵袭性的皮肤淋巴瘤（如原发性皮肤γδ T细胞淋巴瘤）区分开来对于准确判断预后至关重要。我们报告一例26岁亚洲女性的SPTCL病例，该患者有噬血细胞性淋巴组织细胞增生症病史，其四肢和躯干出现非溃疡性红斑斑块和色素沉着结节，持续5个月。活检标本显示非典型淋巴样浸润，具有明显的亲脂性，主要由围绕脂肪细胞排列的非典型中等大小淋巴细胞组成。免疫表型分析显示，病变淋巴细胞为CD3 + /CD4 - /CD8 + /CD7 + T细胞，表达TIA1、颗粒酶B和TCR βF1，同时缺乏CD30和爱泼斯坦-巴尔病毒编码的小RNA表达。有趣的是，表达TCR δ的T细胞密度显著增加，一些围绕脂肪细胞且看似呈肿瘤性。CD123未显示浆细胞样树突状细胞聚集。分子分析显示单克隆TCR β和γ基因重排。尽管γδ T细胞群体升高（占T细胞的20% - 50%）但总体临床、组织病理学和分子学结果，以及疾病未快速进展，支持SPTCL的诊断。尽管在各种良性和恶性皮肤病中均观察到反应性γδ T细胞密度增加或肿瘤细胞中出现γδ T细胞表型，但关于这一现象的文献，尤其是在SPTCL中的文献仍然很少。我们的病例强调了认识到SPTCL中γδ T细胞群体增加对于防止误诊为更具侵袭性的淋巴瘤（如原发性皮肤γδ T细胞淋巴瘤）的重要性，强调了进行全面临床病理相关性分析的必要性。
