15例具有血管周上皮样细胞分化的肿瘤临床病理分析

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阳性率不高。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。     

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.     

Malignant perivascular epithelioid tumor of the vagina: Report of a rare case with brief review of literature

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors with immunohistochemical co‐expression of melanocytic and myoid markers. Vaginal PEComas have been described in only nine cases so far. We describe the case of a 65‐year‐old female with a large growth in the left lateral vaginal wall. Biopsy imprint smears showed dispersed tumor cells with anisonucleosis, multinucleation, and bizarre forms, suggestive of a malignant tumor. Histopathology, however, showed perivascular arrangement of clear epithelioid cells, focal necrosis, intracellular brown pigment in few cells, and mitotic activity at 2 to 3 per 50 high power fields. Immunohistochemical positivity for vimentin, HMB‐45, S‐100 protein, desmin, and MyoD1 assisted in rendering a final pathological diagnosis of malignant PEComa of the vagina. Further work‐up revealed metastatic deposits in liver and retroperitoneal lymph nodes. PEComa arising in vagina is an unusual phenomenon with the malignant variant being an extremely rare tumor. Awareness of the characteristic morphology and utilization of a panel of immunohistochemical stains are mandatory to be able to make a precise diagnosis and appropriate prognostication.     

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 retroperitoneum

Perivascular epithelioid cell tumors (PEComas) are a rare type of mesenchymal neoplasms characterized by a proliferation of perivascular cells with an epithelioid phenotype and expression of myo-melanocytic markers. The majority of PEComas seem to be benign and usually their prognosis is good. Malignant cases are extremely rare, exhibiting a malignant course with local recurrences and distant metastases. We herein report a case of a malignant PEComa arising in the retroperitoneum. The patient was a 55-year-old woman experiencing abdominal discomfort for approximately one month. Ultrasound and computer tomography (CT) scans of the abdomen revealed a solid mass arising from the retroperitoneum. Microscopically, the tumor was composed of epithelioid cells mixed with spindled cells. The nucleus had significant atypia, and the mitoses were obvious. The focal intravascular tumor embolus was visible. Immunohistochemically, the epithelioid tumor cells were positive for HMB45 and Melan-A, and the spindled tumor celLs were positive for SMA and desmin. Seven months after a surgical resection, an ultrasound revealed liver metastases. In conclusion, the malignant PEComas of the retroperitoneum is a very rare neoplasm with unique morphological and immunohistochemical characteristics. It should be differentiated from other epithelioid cell tumors of the retroperitoneum.     

Malignant clear-cell myomelanocytic tumor of broad ligament—a case report

Clear-cell myomelanocytic tumors (CCMT) of the perivascular epithelioid cell tumor (PEComa) family have been recently reported. We report a case involving a 12-year-old girl. The tumor (9 × 7.5 × 7 cm) was a firm, tan–gray mass with heavily dark pigmentation, massive hemorrhage, and necrosis, and was located in the right broad ligament attached to the right ovary. Histologically, the tumor was composed of polygonal cells exhibiting diffuse hemorrhage, multifocal necroses, and vascular invasion. Most of the tumor cells contained melanin pigments with Fontana–Masson positivity and ultrastructurally suspicious, membrane-bound premelanosomes. Immunohistochemical staining was positive against HMB-45 and focally positive for smooth muscle actin. The tumor recurred in the form of multiple conglomerated masses of the right iliac fossa, with the greatest measuring up to 3.8 cm in dimension, within 1 year. Most CCMT are believed to originate from falciform ligament/ligamentum teres. To the best of our knowledge, this is the second report of a CCMT arising in the broad ligament with typical morphology and contributory ancillary results. Further study for proper subclassification of the PEComa family should be validated, not by anatomic site but by clinical behavior.     

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.     

Pancreatic perivascular epithelioid cell tumor (PEComa)

Neoplasms with perivascular épithelioid-cell differentiation (PEComas) are rare tumors with a distinctive immunoreactivity for melanocytic markers. They have been described in various organs. We report an intrapancreatic PEComa discovered in a 46-year-old woman during a workup for diarrhea. CT scan showed a 1.7cm nodule in the body of the pancreas with slight-contrast enhancement at arterial time and isodense at portal time. The aspect was suggestive of an endocrine tumor despite negative somatostatin-receptor scintigraphy. Enucleation was performed. Pathologic evaluation showed a well-circumscribed intrapancreatic tumor consisting of a population of clear to eosinophilic spindle cells and a less abundant population of epithelioid cells arranged around blood vessels. Tumor cells expressed vimentin, HMB45 and actin and only focally S-100 protein, KL1, CD117 and CD34. These features were consistent with a PEComa. Pancreatic PEComas are rare, but should be included in the differential diagnostic of pancreatic clear cells tumors or pancreatic spindle- and epithelioid-cells tumors.     

Renal angiomyolipoma with predominant muscular epithelioid components. 2 cases

We report two cases of pararenal angiomyolipomas, in two middle-aged women without tuberous sclerosis. Both tumors were made of muscular epithelioid cells without atypia, some of which were stained by HMB-45 antibody. The fibrous stroma contained numerous thick-walled blood vessels but no adipose component. The ultrastructural examination revealed that muscular epithelioid cells contained myofilaments and melanosomas. Because of their immunohistochemical and ultrastructural profiles, both tumors may be included in the family of lesions composed of perivascular epithelioid cells (PEC). This tumor type is considered as a particular variant of angiomyolipoma with predominant muscular epithelioid component. The immunohistochemical expression of progesterone and estrogen receptors by both tumors may suggest their hormonodependent character.