摘要目的:总结5例CRTC1::TRIM11融合皮肤肿瘤（CTCT）患者的临床及组织病理特征和分子检测结果。方法:本研究为病例系列研究。回顾性分析2024年1月至2025年6月于中国医学科学院皮肤病医院病理科会诊的5例CTCT患者的临床及病理资料和分子检测结果。结果:CTCT患者5例，女3例，男2例，发病年龄12 ~ 72岁，病程2个月至4年。皮损表现均为无症状结节，长径11 ~ 18 mm，中位长径11 mm，仅1例伴有溃疡；3例皮损位于上肢，1例位于下肢，1例位于面部。5例患者均无淋巴结及其他系统受累。组织病理表现：病变位于真皮或皮下，由上皮样或梭形细胞构成结节状或小巢状，巢间为纤维性基质，肿瘤细胞的胞质透明或偏嗜酸性，轻至中度异形；1例见灶状坏死。病理诊断易被误诊为透明细胞肉瘤或黑色素瘤等恶性肿瘤。免疫组化染色：肿瘤SRY相关HMG盒转录因子10（SOX10）和三结构域蛋白11（TRIM11）5例均为弥漫阳性，S100钙结合蛋白（S100）4例呈弥漫阳性。人黑色素瘤黑素体蛋白抗体45（HMB-45）、黑素细胞抗原A（Melan-A）为阴性或灶状阳性。热点区域的核分裂象为（2 ~ 12）/10个高倍视野，增殖指数Ki-67均不超过10%。5例均通过分离探针的荧光原位杂交检测发现CRTC1基因断裂。2例行RNA测序证实CRTC1::TRIM11融合。3例通过荧光原位杂交技术排除EWSR1基因断裂，3例排除黑色素瘤基因相关异常。5例患者均手术切除肿瘤，随访6 ~ 9个月，均未发生复发或转移。结论:CTCT常表现为无症状结节，具有特征性的组织学表现，免疫组化检测中SOX10、S100、TRIM11常为弥漫阳性，CRTC1基因断裂，分子检测证实CRTC1::TRIM11融合可明确诊断。本病生物学行为偏惰性，手术切除后仍需密切随诊。

abstractsObjective:To summarize the clinical features, histopathological characteristics, and molecular findings of 5 cases of CRTC1::TRIM11 cutaneous tumors (CTCT) .Methods:A case series study was conducted. Clinical data, histopathological findings, and molecular test results were collected from 5 patients with CTCT who underwent a pathological consultation at the Hospital for Skin Diseases, Chinese Academy of Medical Sciences, between January 2024 and June 2025, and were retrospectively analyzed.Results:Of the 5 patients, there were 3 females and 2 males, with ages at onset ranging from 12 to 72 years and disease durations ranging from 2 months to 4 years. All lesions presented as asymptomatic nodules, with maximum diameters ranging from 11 to 18 mm (median, 11 mm) ; ulceration was observed in only 1 case. Lesions were located on the upper extremities in 3 cases, on the lower extremity in 1 case, and on the face in 1 case. None of the 5 patients had lymph node involvement or systemic diseases. Histopathological examination revealed dermal or subcutaneous nodule-like or nest-like structures composed of epithelioid or spindle cells with intervening bands of fibrous tissue; tumor cells exhibited clear or slightly eosinophilic cytoplasm with mild to moderate nuclear atypia; focal necrosis was seen in only 1 case. The entity was prone to be misdiagnosed as malignant tumors such as clear cell sarcoma or melanoma due to its overlapping histopathological features. Immunohistochemically, the tumor cells were diffusely positive for SRY-related HMG box transcription factor 10 (SOX10) and tripartite motif-containing protein 11 (TRIM11) in all 5 cases, diffusely positive for S100 protein in 4 cases, and either negative or focally positive for human melanoma black 45 (HMB-45) and melanoma antigen A (Melan-A). The mitotic count in hotspot areas ranged from 2 to 12 mitoses per 10 high-power fields, and the Ki-67 proliferation index was less than 10% in all cases. Fluorescence in situ hybridization (FISH) with break-apart probes revealed CRTC1 gene break-apart in all 5 cases, and RNA sequencing confirmed CRTC1::TRIM11 fusion in 2 cases. Additionally, EWSR1 gene break-apart was excluded by FISH in 3 cases, and melanoma-associated genetic alterations were also excluded in 3 cases. All the 5 patients underwent surgical excision, and no recurrence or metastasis was observed during a follow-up period of 6 to 9 months. Conclusions:CTCT typically presents as asymptomatic cutaneous nodules with characteristic histopathological features, immunohistochemical study usually shows diffuse positivity for SOX10, TRIM11, and S100, and the detection of CRTC1 gene break-apart and molecular confirmation of CRTC1::TRIM11 fusion could confirm the diagnosis. CTCT often exhibit a relatively indolent biological behavior; however, close follow-up after surgical excision is recommended.