具有血管周上皮样细胞分化的肿瘤15例临床病理分析

目的探讨具有血管周上皮样细胞分化的肿瘤(perivascular epithelioid cell tumor,PEComa)临床病理特征及免疫表型。方法对15例PEComa行EnVision两步法免疫组化及特殊染色,并分析其临床表现、病理学特征和免疫组化特点。结果 15例PEComa中13例为女性,且术后无复发。肿瘤可发生在身体任何部位,以肝脏和肾脏最多见,有包膜,多为实性,可有出血。特征性组织学改变是肿瘤细胞围绕血管生长。PAS染色显示该肿瘤细胞中有糖原物质沉积,弹力纤维染色显示该肿瘤中的血管壁缺乏弹力层。免疫组化显示所有PEComa病例均明显表达HMB-45、Melan-A、SMA,Ki-67阳性率低。结论 PEComa是一组具有恶性潜能的肿瘤,多发于女性,来源于血管周上皮样细胞。大部分肿瘤呈良性过程,生物学分级极低,预后良好;极少部分病例可发生转移,预后不佳。免疫组化检测对其组织来源、生物学行为具有提示意义,并可辅助诊断。     

肺良性血管周上皮样细胞肿瘤9例临床病理观察

目的 探讨肺良性血管周上皮样细胞肿瘤(perivascular epithelioid cell tumor,PEComa)的临床病理特征、诊断及鉴别诊断.方法 回顾性分析9例肺PEComa的临床及影像学资料,总结其组织病理学形态、免疫组化特征及患者预后,并复习相关文献.结果 9例肺PEComa中男性5例,女性4例,4...     

胃TFE3阳性富含色素的血管周上皮样细胞肿瘤1例

胃血管周上皮样细胞肿瘤(PEComa)是一种罕见发生于胃的具有血管周上皮样细胞特征的间叶性肿瘤。本文报道1例发生于胃体上部前壁黏膜下PEComa。内镜下行黏膜下肿物挖除术, 术后病理组织形态表现为富含色素的上皮样肿瘤细胞被含小血管网的间质分隔成巢状。免疫组织化学HMB45、结蛋白、TFE3阳性。最终诊断:胃TFE3阳性富含色素的PEComa。通过分析本例肿瘤临床病理特征, 对胃肠道PEComa临床病理特征、免疫组织化学及分子检测进行回顾性分析, 以提高病理医师对胃肠道PEComa的认识。     

胃肠道TFE3阳性血管周上皮样细胞肿瘤2例临床病理学特征

目的探讨发生在胃肠道, 转录因子E3基因(TFE3)阳性血管周上皮样细胞肿瘤(PEComa)的病理学特征及生物学行为。方法收集2例发生于肠道的恶性PEComa, 并复习相关文献。结果肿瘤浸润肠壁全层, 呈巢片状生长, 均见灶性坏死。肿瘤细胞上皮样, 异型性明显, 核分裂象易见。2例肿瘤细胞均表达黑色素细胞标志物HMB45, 并且伴肌源性标志物表达缺失, 如平滑肌肌动蛋白和结蛋白, 2例免疫组织化学均显示TFE3核阳性, 其中1例行TFE3(Xp11.2)基因断裂探针荧光原位杂交检测, 结果示TFE3基因断裂。结论胃肠道原发, 特别是TFE3阳性的PEComa较为少见, 且临床病理特征有别于一般的PEComa, 需与多种疾病鉴别, 应熟悉其临床病理特征, 避免误诊。     

原发性皮肤血管周细胞肿瘤:皮肤独特的透明细胞病变

血管周细胞肿瘤（PEComa）定义为组织学和免疫组化上由独特的血管周上皮样细胞组成的间叶性肿瘤，该肿瘤常发生于后腹膜、腹腔脏器和盆腔，而发生于躯体软组织和皮肤者非常罕见。作者报道了10例原发于皮肤的PEComa，女性8例，男性2例，年龄15～81岁（平均52岁）。临床表现为无痛性、缓慢生长的真皮结节或斑块，无1例病人有结节性硬化综合症表现。     

子宫血管周上皮样细胞肿瘤2例报道及文献复习

子宫血管周上皮样细胞肿瘤（perivascular epithelioid cell tumor,PEComa）是一种少见的肿瘤,有其特有的镜下特点和免疫组化特征。现收集2例子宫PEComa病例,并结合文献探讨其诊断和鉴别诊断,以提高对该病的认识。     

硬化型上皮样血管肌脂肪瘤

作者报道了2例罕见的上皮样血管肌脂肪瘤（AML），具有显著的硬化间质。2例中年女性患者，无结节性硬化症临床病史。例1发生在肾皮质，直径2cm，例2为肾旁腹膜后肿瘤，直径13cm。2个肿瘤由片状或巢状多角形上皮样或短梭形细胞组成，一致的圆形至卵圆形核，胞质嗜酸性，其间伴有束状透明变性的硬化性间质。例2肿瘤内有小区域看似成熟的脂肪细胞。免疫组化显示2例上皮样肿瘤细胞actin和desmin广泛阳性，MART-1阳性，2例硬化性间质束内有散在HMB-45阳性的细胞。而上皮样肿瘤细胞HMB-45实质上是阴性。作为上皮样血管肌脂肪瘤的亚型或硬化性血管周上皮样细胞肿瘤。作者报道的2例临床病理和免疫组化特征是相似的。     

肠道血管周上皮样细胞肿瘤三例临床病理学特征分析

目的:探讨肠道血管周上皮样细胞肿瘤（PEComa）的临床病理学特征。方法:收集3例肠道PEComa病例的资料,光镜下观察HE、免疫组织化学和特殊染色切片,应用荧光原位杂交（FISH）法检测TFE3基因断裂重组情况,复习相关文献并进行分析总结。结果:肿瘤主要位于肠道黏膜下层和肌层,界限较清,细胞呈上皮样或胖梭形,2例排列...     

子宫血管周上皮样细胞肿瘤3例临床病理分析

目的探讨子宫血管周上皮样细胞肿瘤(perivascular epithelioid cell tumor,PEComa)的临床病理特征、诊断及鉴别诊断等。方法采用免疫组化EnVision两步法对3例子宫PEComa进行检测,并复习相关文献。结果3例肿瘤由梭形细胞和上皮样细胞构成,胞质透明至嗜酸性,间质血管丰富,其中1例肿瘤细胞异型性显著,并见出血、坏死。免疫表型:3例HMB-45阳性,2例SMA、Caldesmon阳性,Melan-A、TFE-3、desmin、CD10、CD117和S-100蛋白均阴性,Ki-67增殖指数5%~30%。随访4~55个月,患者均存活。结论子宫PEComa是一种少见的间叶源性肿瘤,结合组织学形态及免疫表型可辅助诊断。     

硬化型血管周细胞肿瘤:一种好发于腹膜后的特殊亚型的血管周细胞肿瘤

血管周细胞肿瘤（PEComa）是一类显示血管周上皮样分化的相关的间叶性肿瘤，可发生于肠系膜、网膜、胃肠道、子宫、软组织等。作者报道了一种伴有广泛间质透明变性的特殊亚型的PEComa，该组病例共13例，均为女性，年龄34～73岁，平均49岁，其中77％（10例）发生于50～60岁。大体上肿瘤大小4．5cm～28cm，平均9．5cm，其中6例大于10cm。     

Primary perivascular epithelioid cell tumor in the rectum: A case report and review of the literature

Perivascular epithelioid cell tumor (PEComa) is a rare collection of tumors arising in a wide array of anatomic locations. It is characterized by the presence of a peculiar population of myomelanocytic marker-positive perivascular epithelioid cells, and is commonly detected in the uterus. The colorectal area is an uncommon site for primary PEComa. In this study, we describe a 17-year-old patient presenting with a rectal polyp. Histologically, the tumor consisted of sheets of round to polygonal epithelioid cells with clear and granular cytoplasm, and a prominent capillary network. Some of the tumor cells were positive for Fontana-Masson staining. Immunohistochemically, the tumor cells were positive for HMB-45, and were negative for cytokeratin, vimentin, S-100 protein, actin, desmin, EMA, CD34, and c-kit. After finding melanosomes or premelanosomes at the ultrastructural level, the diagnosis of PEComa was made. Although PEComa arising within the intestinal tract is unusual and clinically unexpected, PEComa should be considered in the differential diagnosis of rectal polypoid lesions.     

Malignant perivascular epithelioid cell tumor of the kidney with rare pulmonary and ileum metastases

Aims: To report one case of malignant perivascular epithelioid cell tumor (PEComa) of the kidney with rare pulmonary and ileum metastases and analyze its clinicopathological features. Methods: We analyzed the clinicopathological features of one case of malignant PEComa of the kidney with pulmonary and ileum metastases. Immunohistochemistry staining was performed. Results: The patient was a 48-year-old man with a renal mass approximately 14 cm × 11 cm × 8 cm in size. Microscopically, the tumor was mainly composed of polygonal epithelioid cells with dense eosinophilic cytoplasm and round nuclei with small nucleoli. Focal tumor cells showed pleomorphism with multinucleated giant cells and prominent nucleoli. The tumor cells nests were surrounded by thick-walled irregular blood vessels. Focal fat cells were found within the tumor. Hemorrhage and coagulative necrosis were also present. The tumor cells were positive for vimentin, HMB45, and Melan-A, and focally positive for SMA and S-100 protein. After 5 years and 5.6 years of nephrectomy, the tumor metastasized to the right lung and ileum, respectively. Conclusion: We first reported one case of malignant PEComa of the kidney with pulmonary and ileum metastases. Metastatic PEComa of the lung and ileum should differentiate from primary carcinoma, metastatic carcinoma, malignant melanoma, and gastrointestinal stromal tumor.     

Malignant perivascular epithelioid cell tumor of the colon: report of a case with molecular analysis

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm, and malignant cases are extremely rare. A case of malignant PEComa arising in the colon is described herein. The patient was a 43-year-old Japanese woman without a history of tuberous sclerosis complex. The tumor occurred in the abdominal cavity attached to the serosal side of the descending colon. Histologically, the tumor consisted of sheets or closely packed nests of epithelioid cells with clear or eosinophilic cytoplasms. The tumor cells were positive for HMB-45 but negative for S-100 protein and cytokeratins by immunohistochemical staining. Ki-67 labeling index was 2.9%. Peritoneal dissemination of tumor occurred at 20 months and the patient died of tumor at 38 months after the initial operation. This was considered to be a case of malignant PEComa, based on the histological and clinical features. Tumor cells showed overexpression of cyclin D1 but lacked the loss of heterozygosity of the TSC1 and TSC2 genes. The result suggests that the overexpression of cyclin D1 may play an important role in the tumorigenesis of PEComa. Because PEComas can behave in an aggressive manner, careful follow up is warranted.     

Perivascular epithelioid cell tumor (PEComa) of the pancreas: Immunoelectron microscopy and review of the literature

A perivascular epithelioid tumor (PEComa) is a rare tumor probably arising from the perivascular epithelioid cells. Only three cases of pancreatic PEComa have been reported in the English-language literature. The present report describes an extremely rare case of pancreatic PEComa. A 47-year-old Japanese woman complained of lower abdominal pain and a well-demarcated solid tumor was found in the pancreatic head. There was no history of tuberous sclerosis complexes. Pylorus-preserving pancreaticoduodenectomy was thus performed. There was a well-demarcated, solid tumor measuring 17 mm in the pancreatic head. The tumor was composed of a diffuse proliferation of epithelioid tumor cells with many blood vessels but no adipose tissue. The tumor cells expressed HMB45 and α-smooth muscle actin. Ultrastructurally, the tumor cells possessed many membrane-bound granules that were positive for HMB45 on immunoelectron microscopy. The results of immunoelectron microscopy show that some PEComas possess not only typical melanosomes or premelanosomes but also aberrant melanosomes.     

Perivascular epithelioid cell tumor (PEComa) of the liver: a case report and review of the literature

Perivascular epithelioid cell tumor (PEComa) is rare entity and has been described only recently. By immunohistochemistry and genetics it belongs to the family of tumours which comprises angiomyolipoma, clear cell "sugar" tumor of lung, lymphangioleiomyomatosis and clear cell myomelanotic tumor of ligamentum falciforme/teres hepatis. We describe an unusual case of hepatic PEComa arising in a 55-year-old woman with previous history of glioblastoma. Histologically the tumor grew in expansive way, and was composed of clear and eosinophilic epithelioid cels, without vascular or lipomatous component characteristic of angiomyolipoma. There was mild nuclear pleomorphism, sporadic mitotic activity and haemorrhage without necrosis. On immunohistochemistry, the tumor was HMB-45+50, Melan-A and smooth muscle actin positive. Tyrosinase, S-100 protein, cytokeratin coctail, EMA, vimentin, muscle specific actin, CD10, TTF-1, hepatocyte, desmin and cyclin D1 were negative. Sporadic nuclear p53 positivity was seen. The main differential diagnosis of hepatic PEComa includes clear cell variant of liver cell adenoma and hepatocellular carcinoma, metastases of various clear cell carcinomas and metastasis of malignant melanoma. In respect of uncertain biologic potential of PEComa, long term follow up is indicated.     

Sclerosing variant of perivascular epithelioid cell tumor in the female genital organs

Perivascular epithelioid cell tumor (PEComas), other than angiomyolipoma, clear cell 'sugar' tumor of the lung, and lymphangioleiomyomatosis, is an uncommon mesenchymal neoplasm that arises in the soft tissue and visceral organs. We report herein two cases of sclerosing PEComa; a distinctive variant of PEComa, which is characterized by extensive stromal hyalinization, occurring in the uterus and broad ligament. The patients were 34- and 51-year-old females with no family history of tuberous sclerosis complex. Macroscopically, the tumors had white to gray cut surfaces and were microscopically composed of predominantly spindle- to polygon-shaped cells with clear to slightly eosinophilic cytoplasm and pleomorphic nuclei focally arranged in a perivascular pattern, accompanied by marked stromal hyalinization. These tumor cells were immunohistochemically positive for HMB45 and α-smooth muscle actin. Although this variant of PEComa is very rare, this entity should be considered as a potential primary neoplasm of the female genital organs.     

Malignant perivascular epithelioid cell tumor involving the prostate

Perivascular epithelioid cell tumor (PEComa) is a neoplasm chiefly composed of HMB-45-positive epithelioid cells with clear-to-granular cytoplasm and a perivascular distribution. We describe such a tumor involving the prostate and seminal vesicle in a 46-year-old man. The tumor had characteristic histologic features of PEComa. Immunohistochemically, the tumor cells were positive for HMB-45 but negative for epithelial markers, Melan-A, and S100 protein. The tumor behaved in a malignant fashion, and the patient died of the disease 4 years after diagnosis.     

Expression of CD44 and CD29 by PEComa cells suggests their possible origin of mesenchymal stem cells

Background: Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. The perivascular epithelioid cell (PEC) co-expresses melanocytic and muscle markers. Since no normal counterpart to the PEC has ever been identified in any normal tissue, the cell origin of these tumors is still uncertain. Although, several hypotheses have recently been advanced to explain the histogenesis of PEComa, it remains unclear. Methods: The aim of this study was to discuss whether differential expression of stem cell-associated proteins could be used to aid in determining the histogenesis of PEComa. For this purpose, we detected the immunoexpression of 5 kinds of stem cell markers on PEComas, including CD29, CD44, CD133, ALDH1, and nestin. In addition to observed histopathologic morphology, we also performed PEComa relevant clinical diagnostic markers (HMB-45, SMA, melan-A, Desmin, Ki-67, S-100 and TFE3) to identify whether they belonged to PEComas. Results: Our study included 13 PEComa samples, and we obtained positive immunoexpression results as follows: CD29 (13/13), CD44 (8/13), ALDH1 (10/13), nestin (1/13), and CD133 (0/13). Conclusions: Since CD44 and CD29 are surface proteins associated with MSCs, these results suggest that PEComa might arise from MSCs. However, whether MSCs are the origin of PEComa needs to be further explored in the future.