Perivascular epithelioid cell tumor (PEComa) of the uterus: an outcome-based clinicopathologic analysis of 41 reported cases

The uterus and retroperitoneum have emerged as the most frequently reported anatomic sites of origin of perivascular epithelioid cell tumors (PEComas), a poorly defined neoplasm that is characterized by varying amounts of spindle and epithelioid cells with clear to eosinophilic cytoplasm that display immunoreactivity for melanocytic markers, most frequently HMB-45. Published reports on 41 previously reported uterine PEComas are reviewed in this report. Of these 41 cases, 31 originating in the corpus and for which there was adequate follow-up information (or clinical malignancy) were categorized into 2 groups: (1) a malignant group that was comprised of cases associated with patient death of disease and/or clinical malignancy as evidenced by local and/or distant extension outside of the uterus (n=13, group 1) and (2) a "nonmalignant" group of cases in which neither of the above features were present (n=18, group 2). Groups 1 and 2 did not significantly differ regarding duration of follow-up (25 mo vs. 24.3 mo, respectively, P=0.9) or patient age (45.61 y vs. 43.46 y, respectively, P=0.7). Five of the group 1 patients experienced distant (extra-abdominal) metastases. The group 1 tumors were significantly larger than the group 2 tumors (averages 9.6 cm vs. 4.67 cm respectively, P=0.04); however, there were no size thresholds that, in of themselves, reliably classified 75% or more of the cases in both groups. Coagulative necrosis was highly associated with group 1, being present in 82% of cases as compared with only 11.8% of group 2 cases (P=0.0002). Eighty-eight percent of the group 2 cases had a mitotic rate of 1/10 HPF and/or coagulative necrosis are features that, if present, raise the definite potential for aggressive behavior.     

Perivascular epithelioid cell tumor of the uterus: a case report

A case of a perivascular epithelioid cell tumor (PEComa) arising in the uterus of a 35-year-old woman is presented. Imaging studies revealed a 5 cm well circumscribed mass in the uterine fundus. The tumor was composed of clear to faintly eosinophilic, epithelioid and spindled cells. Immunohistochemically, most tumour cells were strongly positive for HMB-45, smooth muscle actin and desmine, but negative for epithelial markers, S-100 Protein and neuroendocrine markers. Reevaluation of the patient for signs of tuberous sclerosis complex after the diagnosis gave negative results. At the most recent follow-up 4 months later there was no evidence of recurrence.     

子宫血管周上皮样细胞肿瘤临床病理观察

目的研究子宫血管周上皮样细胞肿瘤的病理学特征、诊断、鉴别诊断和生物学行为。方法对5例子宫血管周上皮样细胞肿瘤进行常规组织学和免疫组织化学（SP法）染色和观察,对患者进行随访,并复习相关文献。结果光镜下5例肿瘤均由透明或嗜酸细胞巢或宽窄不等的细胞索组成,间质有丰富的小血管和程度不等的透明变。免疫组织化学染色示5例瘤细胞均黑色素细胞标记阳性和程度不等的结蛋白和平滑肌肌动蛋白（SMA）阳性,CK和CD10阴性。5例患者现均存活。结论子宫血管周上皮样细胞肿瘤具有较特征性的组织病理及免疫组织化学特点,HMB45阳性对诊断有重要作用。该肿瘤分良性、恶性潜能不能确定和恶性三类,应与透明细胞癌和上皮样平滑肌肿瘤区别。     

Perivascular epithelioid cell tumor of the uterus: immunohistochemical, ultrastructural and molecular study

A case of perivascular epithelioid cell tumor of the uterus is reported, occurring in a 32-year-old woman. The tumor (8.0 cm in dimension) showed exophytic growth from the outer half of the myometrium. Histopathologically, the tumor was composed of thick blood vessels and perivascular epithelioid cells. The neoplastic cells were strongly immunoreactive for HMB45 antigen, CD117 (c-kit), vimentin and the progesterone receptor, but completely negative for S-100 protein, smooth muscle actin, desmin, CD34, the estrogen receptor and p16. The Ki-67 labeling index was low (1.25%). Ultrastructurally, the neoplastic cells had numerous premelanosomes with some glycogen deposits. Single-stranded DNA conformational polymorphism of p53 and methylation-specific polymerase chain reaction of p16 revealed negative results. Definite melanosomes on electron microscopic analysis and coexpression of HMB45 antigen and stem cell factor receptor (CD117) may provide the clue to understanding perivascular epithelioid cell tumor because angiomyolipoma also coexpresses HMB45 antigen and CD117.     

非特殊性血管周上皮样细胞肿瘤31例的病理学观察

目的 探讨非特殊性血管周上皮样细胞肿瘤(PEComa-NOS)的临床病理学特征,评价恶性血管周上皮样细胞肿瘤(PEComa)的诊断标准.方法 回顾性复习31例PEComa-NOS的临床表现、影像学资料、光镜形态和免疫学表型,分析预后资料.2例为空芯针穿刺活检标本,2例为剖腹探查活检标本,其余27例为手术切除标本.结果 ...     

Angiolymphoid hyperplasia with eosinophilia (epithelioid hemangioma) of the lung: a clinicopathologic and immunohistochemical study of two cases

Two cases of primary angiolymphoid hyperplasia with eosinophilia (epithelioid hemangioma) (ALHE/EH) of the lung are described. Both patients are white, a 60-year-old man and a 27-year-old woman. One patient had a long-standing history of asthma, and the other had symptomatology related to the pulmonary mass. Wedge resections were performed in both cases, and both lesions shared similar histopathologic changes, mainly the presence of a tumor mass with a marked presence of eosinophils in the background, lymphoid hyperplasia, and marked proliferations of small-caliber vessels. Immunohistochemical studies using leukocyte common antigen, L-26, and UCHL-1 nicely stained the lymphoid component of the lesion, and CD31 clearly outlined the vascular component of the process. Clinical follow-up demonstrated that the woman died of status asthmaticus, and the man was alive and well 1 year after surgical resection of the lesion. Both cases highlight the ubiquitous distribution of ALHE/EH and underscore the importance of keeping these lesions in the differential diagnosis of vascular and lymphoid lesions of the lung.     

4例胃肠道血管周上皮样细胞肿瘤临床病理学分析

目的 探讨胃肠道血管周上皮样细胞肿瘤(perivasculaRepithelioid cell tumor,PEComa)的临床及病理学特点.方法 回顾性复习4例胃肠道原发血管周上皮样细胞肿瘤的病理切片及临床资料,选取典型蜡块做相关的免疫组化染色,抗体包括黑色素相关抗原HMB45、melan-A、肌源性标记抗原SMA、desmin,以及vimentin、CgA、CK、S-100、CD117、CD34.结果 4例PEComas中男性3例,女性1例,年龄分别为36、38、42及45岁.其中2例位于升结肠,1例位于降结肠,1例位于乙状结肠.肿瘤大小4.5～10 cm,境界清楚,切面灰白色,质地均匀,局部可见出血.镜检:肿瘤细胞呈上皮样排列,细胞质丰富,透亮或嗜酸性颗粒状,细胞核空泡状,有明显的核仁,间质富于毛细血管、血窦以及厚壁血管.细胞异型性小,个别病例局部可见轻～中度异型性,分裂象0～3个/10 HPF.免疫组化结果 :肿瘤弥漫表达HMB45(4/4),弥漫或片状表达vimentin(4/4)、SMA(4/4)以及desmin(3/4).CgA、Syn、CK、S-100、CD117、CD10及CD34均阴性.4例患者行局部肠管及肿瘤切除,术后随访8、15、32及36个月均无复发和肿瘤转移.结论 胃肠道PEComa少见,为低度恶性潜能肿瘤,形态类似于软组织和其他部位的同类肿瘤,手术切除为首选治疗.     

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...     

Proximal-type epithelioid sarcoma: a clinicopathologic study of 20 cases.

We studied the clinicopathologic and immunohistochemical features of 20 cases of proximal-type epithelioid sarcoma to identify prognostic factors. The 20 patients ranged in age from 13 to 80 years (mean, 40 y); 12 patients were male and 8 were female. The tumors presented as deep soft-tissue or subcutaneous masses on the inguinal region in five, the thigh in four, the vulva in three, the axilla in three, and one each in the flank, chest wall, back, hip and perineum. The tumors ranged from 2 to 16 cm at their greatest diameter (mean: 7.8 cm). Histologically, 12 tumors (60%) were classified as the large-cell subtype, characterized by sheets of large cells with prominent nucleoli resembling poorly differentiated carcinoma, and a frequent rhabdoid phenotype, six (30%) were classified as the conventional subtype, and two (10%) as the angiomatoid subtype. The numbers of tumors exhibiting immunoreactivity for various markers were: vimentin (20 cytokeratin (20 [100%]); epithelial membrane antigen (17 [85%]); CD34 (9 [45%]); CD99 (5 [25%]); muscle markers, either desmin or alpha-smooth muscle actin (3 [15%]), other markers such as S-100 protein, neurofilament, neuron-specific enolase, synaptophysin and CD56 (12 [60%]); and p53 (16 [80%]). Fourteen lesions (70%) exhibited an MIB-1 index of 30% or more and, by a system of histologic grading using the MIB-1 score, 16 tumors (80%) were classified as high-grade (Grade 3). Thirteen patients (65%) developed local recurrence and 15 (75%) had metastases, primarily to the lymph nodes. At the last follow-up, 13 patients (65%) had died of their disease. A large tumor size and early metastasis were independently associated with a poor outcome. We conclude that proximal-type epithelioid sarcomas are rare, undifferentiated soft-tissue sarcomas of adults, with epithelioid features and a frequent rhabdoid phenotype. These tumors, when arising in proximal locations, have a much worse prognosis than those arising in distal locations.     

Primary mediastinal giant cell tumors: a clinicopathologic and immunohistochemical study of two cases

Two cases of posterior mediastinal giant cell tumors are presented. The patients are a woman and a man, 31 and 18 years old, respectively. One of the patients had symptoms of paresthesias while the other was completely asymptomatic. Complete physical examination did not disclose evidence of tumor elsewhere. Neither patient had a previous history of malignancy. Surgical resection was performed. Histologically, both tumors were composed of a proliferation of osteoclast-like giant cells associated with a mononuclear cell population composed of oval and spindle cells. Mitotic activity and mild cellular atypia were present in the mononuclear cell component. No evidence of necrosis or hemorrhage could be demonstrated in either case. Immunohistochemically, both tumors showed strong positive reaction in the mononuclear component for antibodies against vimentin and CD68, while keratin, epithelial membrane antigen, CD45, S-100 protein, and desmin were negative. On clinical follow-up, both patients are alive and well without evidence of recurrence or metastasis 6 and 108 months after surgery. The present cases highlight the ubiquitous distribution of soft tissue giant cell tumors and the importance of considering these tumors in the differential diagnosis of posterior mediastinal neoplasms.     

子宫血管周上皮样细胞肿瘤

例1女,33岁。2002年2月开始感觉腰酸、腹胀、经量增多来我院就诊。妇科检查示子宫前位,增大如孕2个月左右。B超检查子宫前壁峡部一7·7cm×6·5cm×5·5cm大小低回声团块,向浆膜面突出,内部光点分布不均匀,以后每年定期2次子宫附件B超检查,均示子宫峡部肿块逐渐增大,考虑子宫平滑肌瘤。2004年9月B超检查示子宫前壁峡部一8·5cm×4·3cm×6·4cm低回声团块,周边见血流信号,其内见2·0cm×1·9cm不规则液性暗区,子宫内膜及两侧附件无特殊。诊断为子宫肌瘤部分液化行子宫全切术。CA199、CA125、癌胚抗原(CEA)等各项实验室检查均无异常。术…     

Perivascular epithelioid cell tumor (PEComa) of soft tissue: case report with ultrastructural study

A perivascular epithelioid cell tumor (PEComa) arising in the abdominal wall of a 44-year-old female is described. The lesion was a well-circumscribed but unencapsulated, rubbery, subcutaneous mass measuring 3.5 x 3.5 x 3.0 cm which was removed by simple excision. It was characterized by a nest- or sheet-like arrangement of round to polygonal cells with round nuclei and abundant clear to slightly eosinophilic cytoplasm containing glycogen. There was mild to moderate nuclear pleomorphism with mitotic activity of 6 per 10 high power fields. A short fascicular proliferation of the tumor cells was observed focally. The stroma contained abundant small vascular channels with hyalinization. Immunohistochemically, the tumor cells were strongly positive for vimentin, epithelial membrane antigen, alpha-smooth muscle actin, and HMB45. Ultrastructural examination showed poorly differentiated mesenchymal tumor cells without premelanosomes. There was local recurrence 6 years after excision. Pathologists and clinicians should be aware of the existence of PEComa in soft tissue and should differentiate it from other similar lesions.     

硬化性上皮样纤维肉瘤的临床病理学观察

目的探讨硬化性上皮样纤维肉瘤的临床病理学特征、免疫表型及鉴别诊断.方法应用光镜和免疫组织化学LSAB法对8例硬化性上皮样纤维肉瘤进行临床病理学分析和免疫表型检测.结果患者均为成年人,男性5例,女性3例,年龄35～54岁(平均45岁).临床上表现为深部软组织内缓慢性生长的肿块,其中大腿/臀部3例,右上臂/肩部2例,胸壁和背部2例,小腿1例.大体上,肿块呈结节状,境界相对清楚,直径2.0～10.5 cm(平均6 em),切面呈灰白色,质地坚韧或有弹性.组织学上,肿瘤由形态一致、小至中等大的圆形或多边形上皮样细胞组成,多呈单个或狭窄的条索状排列,夹杂于大量嗜伊红色、玻璃样变的胶原纤维之间.部分区域中也可排列成巢状、片状或腺泡状.高倍镜下,瘤细胞的胞质透亮或嗜伊红色,核异型性不明显,核分裂象也少见(＜1/10HPF).另在2例肿瘤的局部区域,细胞密度明显增加,核有显著的异型性,核分裂象也易见,类似经典的纤维肉瘤.免疫组织化学标记显示,瘤细胞弥漫强阳性表达波形蛋白,灶性或弱阳性表达上皮膜抗原,不表达细胞角蛋白、S-100蛋白、HMB45、肌动蛋白、结蛋白、CD34、bcl-2、CD30和白细胞共同抗原(LCA)等标记.随访6例,3例复发,1例发生肺部转移.结论硬化性上皮样纤维肉瘤是纤维肉瘤的一种少见亚型,尽管瘤细胞异型性不明显,核分裂象也少见,但肿瘤可发生局部复发及远处转移,临床上应视为一种低至中度恶性的软组织肉瘤处理,组织学上则应注意与一些具有上皮样形态和硬化性间质的肿瘤相鉴别.     

Perivascular epithelioid cell tumor of the pericardium: a case report.

A large pericardial mass, which was found to be a perivascular epithelioid cell tumor, was excised from a 20-year-old man. To our knowledge, this is the first report of this distinctive neoplasm as a pericardial mass.     

Perivascular epithelioid cell sarcoma (malignant PEComa) of the ileum

Epithelioid angiomyolipoma (AML) is the prototype of a heterogeneous group of lesions characterized by the presence of HMB-45 positive cells with clear cytoplasm, perivascular distribution, and combined myomelanocytic features, so-called perivascular epithelioid cells (PECs). These lesions are being increasingly referred to as PEComas. PEComas have been reported at diverse anatomic sites, but mainly in the abdominopelvic cavity and rarely in parenchymatous organs, skin, and soft tissues. Gastrointestinal (GI) PEComas are exceptionally rare, with less than 10 cases documented so far. Rare examples of PEComas with pleomorphic histology could have been misinterpreted as unusual variants of carcinoma or sarcoma. To make a contribution to the differential diagnosis of difficult-to-classify pleomorphic GI sarcomas, we report on a malignant pleomorphic neoplasm with features of PEComa involving the terminal ileum in a 63-year-old woman. Fourteen months after resection of the primary tumor, a huge abdominopelvic recurrence was successfully resected, but no distant metastases were detected. The differential diagnosis and malignancy criteria of GI PEComas will be discussed.     

Intranasal mixed tumors (pleomorphic adenomas): a clinicopathologic study of 40 cases.

The clinical, gross, and microscopic features of 40 cases of intranasal mixed tumor (pleomorphic adenoma) are reviewed and studied. The majority of these neoplasms originate from the mucosa of the bony or cartilaginous septum; they also occur on the lateral nasal wall. They may be found at any age, but the majority of our cases occurred in persons in the third through sixth decades of life. There was no significant sex predilection. All patients whose race was recorded (35) were Caucasian. The patients commonly had symptoms of nasal obstruction or the presence of a mass in the nasal cavity, or both. Clinically, the lesions were not unique, frequently being described only as polypoid, broad-based swellings. Microscopically, although similar to mixed tumors of major salivary glands, these tumors differed by being highly cellular (epithelial), with little or no stromal component, and thus simulated more aggressive epithelial neoplasms. Follow-up data (mean 7.5 years) in 34 of the 40 cases showed no evidence to suggest aggressive behavior. Thirty-one of the 34 cases followed showed no recurrence, regardless of the type of excisional procedure used. Those that did recur were either persistent from inadequate primary excisions (2 cases) or recurred locally (1) and were removed without sequelae. Local but adequate excision appears to be the treatment of choice.     

Perivascular epithelioid cell tumour (PEComa) of the soft tissue

AIMS: PEComa is a rare tumour developing from perivascular epithelioid cells (PEC) and is characterised by positive immunoreactivity for HMB45. Since PEComas are tumours having both a spindle cell component and an epithelioid and giant cell component, as seen in many sarcomas, as well as having a wide distribution in various organs and soft tissue, we reviewed cases originally diagnosed as sarcomas of the soft tissue in our institution and screened them by immunostaining for HMB45. METHODS: Consecutive soft tissue sarcomas (31 tumours) retrieved from the Surgical Pathology file at our institution for a period of 3 years were submitted for immunostaining for HMB45. Cases with positive HMB45 immunostaining were submitted for further immunostaining for MART1, CD68, S100 protein, cytokeratin AE1/3, EMA, vimentin, MSA and CD117. RESULTS: Of 31 sarcomas, three tumours in the group of 11 malignant fibrous histiocytomas (MFH) and unclassified sarcomas showed positive immunoreactivity for HMB45 and MART1 in 1-25% of tumour cells. The three tumours were located in the lower extremities and measured 8, 11 and 12 cm in diameter. Patient gender male:female was 2:1 and ages were 46, 56 and 60 years. Microscopically, the tumours were composed of a variable proportion of spindled cells, multinucleated cells and epithelioid cells disposed in diffuse sheets or nests. Mitotic figures and necrosis were frequent. The immunoreactivity was diffuse for CD68, focal for AE3 and EMA, negative or focal for MSA and CD117, and negative for S100 and AE1. All three patients developed lymph node or distant metastases and died of the disease within 1-2 years. CONCLUSIONS: PEComa re-screened from the group of high grade sarcomas without definite differentiation range from pleomorphic to monomorphic cytohistopathological features. Immunostaining for HMB45 of unclassified sarcomas is useful for the classification of these tumours. They occur preferentially in the lower extremities and have a high malignant potential when associated with large size, tumoural necrosis and high mitotic activity.