Abstract:
Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of TFE3-rearranged perivascular epithelioid cell tumor (PEComa). Methods: Eight cases of PEComa with TFE3 rearrangement diagnosed in the First Affiliated Hospital of Air Force Medical University from January 2014 to July 2022 were collected. Three were consultation cases and 5 were collected from our hospital; 7 cases were resection specimens and 1 case was a needle biopsy specimen. Routine histolopathological analysis, immunohistochemical staining, fluorescence in situ hybridization (FISH) and the next-generation sequencing were performed. Clinical data were collected and the prognosis was assessed. Results: The 8 patients consisted of 5 females and 3 males with a median age of 45 years (ranged from 25 to 65 years). The tumor location included 1 uterus, 1 liver, 1 urachus, 2 kidneys, 1 abdominal cavity, 1 colon, and 1 retroperitoneum (3 subsequent recurrences in the abdominal cavity, pelvis and ovary, and abdominal cavity, respectively). Morphologically, the tumor cells were uniform and epithelioid with translucent or eosinophilic cytoplasm. They were arranged in nests or sheets, most of which were separated by thin-walled blood vessels. There were no papillary structures, and no overt smooth muscle or fat components. Atypical features were seen in 3 cases, with bizarre nuclei and tumor giant cells. Large areas of necrosis were visible, and mitosis was common (up to 28/50 HPF). Melanin deposition was present in 3 cases. Immunohistochemical staining showed diffuse and strong positivity for TFE3 in 8/8 cases and for HMB45 in 6/8 cases; focal positivity for Cathepsin K and Melan-A in 6/8 cases and for SMA in 2/8 of cases. All cases were negative for CKpan, PAX8 and Desmin. TFE3 gene break-apart was detected by FISH in all 8 cases, 4 of which underwent next-generation sequencing, and it revealed that 2 cases presented with SFPQ::TFE3 fusion, 1 case with ASPSCR1::TFE3 fusion, and 1 case with no chimeric fusion. Seven cases were followed up for 4-94 months. All cases were alive; 4 cases were disease-free, 2 cases showed recurrence, and 1 case had metastasis at initial diagnosis. Conclusions: TFE3-rearranged PEComa has unique histomorphological, immunohistochemical and molecular characteristics. The biological behavior is aggressive, which could lead to recurrence and metastasis, and warrants close clinical follow-up.
目的: 探讨TFE3重排的血管周上皮样细胞肿瘤(perivascular epithelioid cell tumor,PEComa)的临床病理特征、免疫表型、分子遗传学特征及预后。 方法: 收集空军军医大学第一附属医院2014年1月至2022年7月诊断的8例TFE3重排的PEComa,3例为会诊病例,5例为本院标本,其中7例为手术切除标本,1例为穿刺活检标本。对其进行常规组织学分析、免疫组织化学染色、荧光原位杂交(FISH)及二代测序检测,并进行预后随访。 结果: 8例患者中,5例为女性,3例为男性,年龄25~65岁(中位年龄45岁)。发病部位:子宫1例,肝脏1例,脐尿管1例,肾脏2例,腹腔1例,结肠1例,腹膜后1例(后3次复发,部位分别为腹腔、盆腔和卵巢、腹腔)。组织形态学:肿瘤细胞呈上皮样,大小形态较一致,胞质透亮或嗜酸,巢片状排列,大部分区域由纤细的薄壁血管分隔形成巢泡状,未见乳头状结构,无明显的平滑肌及脂肪成分;3例细胞异型性显著,可见奇异形核及瘤巨细胞并伴有大片坏死,核分裂象多见(最多约28个/50 HPF)。3例可见黑色素颗粒沉着。免疫组织化学染色结果:所有病例均弥漫一致强阳性表达TFE3,8例均表达HMB45(2例灶状阳性),6例(6/8)表达Cathepsin K和Melan A,2例(2/8)表达平滑肌肌动蛋白(均为灶状阳性),所有病例均不表达广谱细胞角蛋白、PAX8和结蛋白。8例FISH均检测到TFE3基因断裂,其中4例进行了二代测序,显示2例具有SFPQ::TFE3融合,1例具有ASPSCR1::TFE3融合,另1例未检出。7例随访到有效信息,随访时间4~94个月,4例无病生存,2例复发,1例初诊时已出现转移,所有患者均未死亡。 结论: TFE3重排的PEComa具有独特的组织形态学特征、免疫表型及分子特征,具有侵袭性的生物学行为,个别病例表现出高度恶性的生物学行为,可出现复发和转移,应提示临床进行密切随访。.