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.     

子宫血管周上皮样细胞肿瘤临床病理学观察

子宫血管周上皮样细胞肿瘤(perivascular epithelioid cell tumor,PEComa)是一种非常罕见的肿瘤,极易误诊.作者在病理诊断中诊断1例,结合文献复习报道如下.     

鼻腔血管周上皮样细胞肿瘤临床病理分析

目的 探讨血管周上皮样细胞分化肿瘤(neoplasm with perivascular epithelioid cell differentiation,PEComa)的临床病理特征,并对国内外相关文献进行复习,以提高对PEComa的认识和病理诊断水平.方法 对1例PEComa进行临床表现分析,对其病理组织学和免疫组化染色进行观察,并结合国内外相关文献复习PEComa的特点.结果 患者发现左鼻腔无痛渐大性肿物伴反复出血1年余.组织病理学形态表现为裂隙状血管周围见片巢状排列的上皮样细胞,细胞胞质透亮,内含淡红色细颗粒状,核小且一致,圆形或卵圆形,核仁小,核分裂罕见.免疫表型:HMB-45、Melan-A、vimentin和SMA(+);S-100蛋白、CK和EMA(-).结论 发生于鼻腔的PEComa罕见,诊断主要依靠病理学,手术切除为首选治疗,其为低度恶性潜能肿瘤,需长期随访.     

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。     

子宫体恶性血管周上皮样细胞肿瘤1例并文献复习

目的 探讨子宫体恶性血管周上皮样细胞肿瘤(perivascular epithelioid cell tumors,PEComa)的临床病理学特征、诊断及鉴别诊断.方法 采用免疫组化SP法对1例子宫体恶性PEComa进行免疫组化标记并复习相关文献.结果 患者扪及下腹部巨大肿块6个月,手术切除后11个月复发,CT示中下腹一巨大低-高密度混杂肿块.眼观:原发和术后复发肿瘤均体积巨大,切面为灰黄、灰红色,边界不清,质脆伴坏死.镜检:瘤细胞呈上皮样,胞质嗜酸性至透明,细胞异型性明显,可见明显核仁,未见核分裂.免疫组化:vimentin、HMB-45和Melan-A均(++),PNL2(|||),Ki-67增殖指数约3%,EMA、CK(AE1/AE3)、S-100、CD10、desmin、SMA和MSA均(-).结论 子宫体恶性PEComa十分罕见,需与子宫体恶性黑色素瘤、上皮样平滑肌肿瘤和横纹肌肉瘤相鉴别.     

硬化性血管周上皮样细胞肿瘤

具有血管周上皮样细胞分化的肿瘤（PEComas）是间胚叶肿瘤的一个家族，包括血管肌脂肪瘤、肺透明细胞“糖”瘤、淋巴管肌瘤病和发生在软组织、内脏器官和皮肤的一组罕见病变。作者描述了一种特殊变异的PEComa，表现为广泛的间质透明变性，该特征先前在这些肿瘤中尚未描述过。     

恶性血管周上皮样细胞肿瘤2例并文献复习

目的 探讨恶性血管周上皮样细胞肿瘤(malignant perivascular epitheliod cell tumor,PEComa)的临床、病理特征及鉴别诊断.方法 对2例恶性PEComa进行临床、病理形态学、免疫表型及电镜观察,并复习相关文献.结果 镜下见肿瘤组织由梭形细胞及上皮样细胞构成,细胞异型性明显,细胞胞质透明或嗜酸,细胞核大,有核仁,瘤细胞由纤细的纤维结缔组织及薄壁血管将其分隔成巢状、腺泡状、片状结构,部分区域可见多核瘤巨细胞伴肿瘤坏死,核分裂多见.免疫表型:肿瘤细胞表达HMB-45、S-100、SMA及desmin;电镜下见肿瘤细胞胞质内可见高电子密度核心的内分泌小体和少许不成熟的黑色素小体.结论 恶性PEComa罕见,病理形态多样,熟悉其临床、病理形态、免疫表型及电镜下改变,有助于临床、病理医师对其正确诊断及鉴别诊断.     

子宫血管周上皮样细胞肿瘤1例

患者,68岁,以"阴道不规则出血3 个月"为主诉,月经规律4～5 天/30天,56 岁绝经.3 个月前阴道出血,量少;3天前阴道出血增多,因症状持续存在而就诊.彩超示:子宫后位,长径38 mm,前后径28 mm,横径35 mm,内膜厚3 mm,轮廓清晰,形态正常,肌层回声不均.子宫宫底部可见大小21 mm ×15 mm...     

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。     

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...     

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.     

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.     

Ultrasound‐guided fine needle aspiration cytology in the diagnosis of hepatic and pancreatic perivascular epithelioid cell tumors: A case series

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors that can affect any part of the body. They can be sporadic or arise in the setting of tuberous sclerosis (TSC). In this article, we report a series of three hepatic and two pancreatic PEComas diagnosed preoperatively with ultrasound‐guided fine needle aspiration (FNA). All patients were female (age range 28‐70), had no personal history of TSC and presented with a single, localized painless mass. Rapid on‐site evaluation (ROSE) of cytologic samples was performed for all cases to evaluate for cellular content and adequacy of specimens. Direct smears and cell block preparations revealed a proliferation of medium to large polygonal epithelioid cells, with abundant eosinophilic and vacuolated cytoplasm, arranged in sheets and nests. On immunohistochemistry (IHC), neoplastic cells showed co‐expression of melanocytic and smooth muscle markers and a diagnosis of PEComa was rendered. PEComas of the pancreas and liver are rare neoplasms, but should always be considered when examining “clear cell” neoplasms, especially in young female patients. If good quality cytologic samples are obtained by FNA, a correct diagnosis can be achieved with the help of IHC. This is of particular importance in order to plan adequate surgical strategy and to avoid overtreatment.     

Minute perivascular epithelioid cell (PEC) nests in the abdominal lymph nodes—a putative precursor of PEComa

A perivascular epithelioid cell tumor (PEComa) is a peculiar growth defined as a mesenchymal tumor composed of histologically and immunohistochemically distinct perivascular epithelioid cells (PECs). Because neither normal counterparts nor precursor lesions of PEComa have been identified, we examined minute PEC nests, ranged from 0.8 mm to 10 mm, to investigate the possible origin of the PEComa. We examined a total of 80 677 para‐aortic and pelvic lymph nodes that were systematically dissected from 1656 patients for gynecological malignancies. The identified lesions were confirmed immunohistochemically with multiple PEC markers, including smooth muscle actin, HMB45, melan‐A, MiTF, ER and PgR. A total of 66 minute PEC nests were found in 21 patients (1.3% of the total population) with an average frequency of 3.1 lesions per patient. In cases of multiple involvement, 11 of 13 nests were located at the same level of multiple lymph node or on continuous levels. The lesions were preferentially distributed at the level of para‐aortic and high pelvic lymph nodes. All nests were positive for actin and HMB45, whereas the other markers were positive with varying frequencies. The minute PEC nests may be associated with the possible normal counterpart of PEComas.     

Primary perivascular epithelioid cell tumor of the bladder

The perivascular epithelioid cell family of tumors includes angiomyolipoma, clear cell “sugar” tumor of the lung, lymphangioleiomyomatosis, and clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres. Less frequently, perivascular epithelioid cell tumors arise in various other locations throughout the body including soft tissue, bone, and visceral organs. We report a case of a 23-year-old man who presented with 2-month history of frequent micturition and odynuria. Based on clinical examination, ultrasound computed tomography imaging, surgical operation, and histopathologic studies, a definitive diagnosis was made. Further characteristic images and pathology of this disease are discussed.     

Incidental perivascular epithelioid cell tumor in an inguinal hernia sac

Perivascular epithelioid tumors (PEComa) are uncommon mesenchymal neoplasms demonstrating positivity for muscular and melanocytic immuno-markers. Included in this category are angiomyolipoma, lymphangioleiomyomatosis, and clear cell sugar tumors. Lesions which do not fit into these categories are classified as “not otherwise specified”. We present a case of an incidentally discovered PEComa within inguinal hernia sac contents in a 70-year-old woman. It consisted of spindled and epithelioid cells with bland oval nuclei, small nucleoli and clear to light eosinophilic cytoplasm. There was no atypia or mitoses. The lesion was strongly positive for HMB45 and smooth muscle actin. Pelvic soft tissue and peritoneal PEComas are rarely reported in literature and very little is known about their prognosis. We discuss the immunohistochemistry, differential diagnosis, and pathogenesis of PEComas.     

Perivascular epithelioid cell tumor of the pancreas: case report and literature review

Neoplasms with perivascular epithelioid cell differentiation (PEComas) of the pancreas are rare, and only 22 cases have been reported globally. Therefore, clinician and pathologist knowledge of this tumor’s biologic behavior and molecular genetics has been limited. A 40-year-old female patient presented with a space-occupying mass in the pancreas found by abdominal B-mode ultrasonography upon physical examination. Laparoscopic resection of the pancreatic body and tail was performed, and a cystic-solid tumor of about 2 × 2 cm was identified. PEComa is a type of mesenchymal tumor with uncertain biologic behavior, more frequently found in females. PEComa features a unique histomorphology and immunophenotype. We summarize the characteristics and research progress of the pancreatic PEComa, which will be convenient for physicians and pathologists to fully understand the disease to avoid misdiagnosis and to provide a reference for treatment and prognosis.     

Comparative genomic hybridization study of perivascular epithelioid cell tumor: molecular genetic evidence of perivascular epithelioid cell tumor as a distinctive neoplasm

Perivascular epithelioid cell tumor (PEComa) is a neoplasm composed chiefly of HMB-45-positive epithelioid cells with clear to granular cytoplasm and a perivascular distribution. Such tumors have been reported in different organs under a variety of designations. The cytogenetic features of these neoplasms have not been well studied. We collected 9 tumors (5 of kidney, 1 of prostate, 1 of urinary bladder, 1 of the pelvic cavity soft tissue, and 1 of uterus) from 8 patients, including one patient with tuberous sclerosis complex. The paraffin blocks of tumor tissue were submitted for comparative genomic hybridization analyses. Gross chromosomal aberrances were observed in all cases. The frequent imbalances were losses on chromosome 19 (8 cases), 16p (6 cases), 17p (6 cases), 1p (5 cases), and 18p (4 cases) and gains on chromosome X (6 cases), 12q (6 cases), 3q (5 cases), 5 (4 cases), and 2q (4 cases). The frequent deletion of 16p in which TSC2 gene is located indicates the oncogenetic relationship of PEComas with angiomyolipoma as a TSC2-linked neoplasm. From a molecular genetic perspective, the recurrent chromosomal alterations in both renal and extrarenal tumors further support the concept of PEComa as a distinctive tumor entity regardless of anatomic location.     

Constant allelic alteration on chromosome 16p (TSC2 gene) in perivascular epithelioid cell tumour (PEComa): genetic evidence for the relationship of PEComa with angiomyolipoma

Perivascular epithelioid cell tumours (PEComas) are a family of tumours including classic angiomyolipoma, lymphangioleiomyomatosis, and clear epithelioid cell tumours reported under a variety of names such as epithelioid angiomyolipoma, pulmonary and extrapulmonary clear cell sugar tumour, and PEComa. Our previous comparative genomic hybridization study of PEComas demonstrated recurrent chromosomal aberrations including deletions on chromosome 16p, where the TSC2 gene is located. In this study, we focused on the alteration of chromosome 16p, including TSC2. We collected ten sporadic and two tuberous sclerosis complex-associated PEComas, as well as 14 sporadic classic hepatic and renal angiomyolipomas (AMLs) as controls. We used 16 microsatellite markers distributed along chromosome 16p to test for allelic imbalances on chromosome 16p and at TSC2, and two markers for TSC1. Furthermore, we carried out immunohistochemical staining for phospho-p706K, phospho-AKT, and phospho-S6 to evaluate the effect of TSC2 alterations on the mTOR signalling pathway. Loss of heterozygosity (LOH) was found in 11 PEComas and involved the region of the TSC2 locus in seven. Six classic angiomyolipomas had allelic changes at chromosome 16p. Microsatellite instability was detected in two PEComas. The incidence of genetic aberrations was significantly higher in the PEComa group. Only one PEComa showed LOH at the TSC1 locus. Eleven PEComas and 13 AMLs revealed elevated phospho-p70S6K accompanied by reduced phospho-AKT. Five PEComas and eight classic angiomyolipomas were positive for phospho-S6. The phosphorylation profile indicates functional activation of the mTOR pathway through a disrupted TSC1/2 complex. Our observations of frequent deletion of TSC2 and the mTOR signalling pathway provide evidence that the oncogenetic lineage of PEComa, as a distinct TSC2-linked neoplasm, is similar to that of angiomyolipoma.