Primary perivascular epithelioid cell tumor (PEComa) of the liver: Report of a case

PEComa is very rare mesenchymal neoplasm which is formed by perivascular epithelioid cells and is characterized by dual melanocytic and myoid differentiation. Up to now only a very few cases of PEComa of the liver have been described worldwide. We herein present a patient who underwent a right hemihepatectomy for a huge tumor which could not be identified by imaging investigations. A final histopathologic examination revealed a benign epithelioid tumor with a solid growth pattern, abundant vascularity, and frequently dilated vascular channels. Immunohistochemically, the tumor cells were strongly positive for HMB-45, moderately positive for actin, and faintly positive for S-100, respectively. Based on the above findings, a diagnosis of a primary clear cell “sugar” tumor was established. Because the natural history of PEComas is mostly unpredictable, the patient has been closely followed up; however, no recurrence has so far been observed. Immunohistochemical findings play a crucial role in avoiding a misdiagnosis, and a surgical resection with an adequate margin of healthy tissue remains the gold standard of treatment. A long-term periodic follow-up is reasonable in all cases presenting with PEComa.     

PEComa of the talus: a unique case of a soft tissue tumor within bone

Introduction: Perivascular epithelioid cell tumor (PEComa) is a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells (PECs). These tumors have been described at multiple anatomic sites. PEComas presenting in bone are especially rare and they have been reported to be either primary or metastatic lesions. None of them is located at the level of the foot.

Patient: We report on a case of primary bone PEComa of the talus, the first one to be published to the best of our knowledge.

Treatment and result: Limb sparing surgical treatment has been done using intralesional tumor removal, burring and application of argon beam at the tumor walls and primary filling of the tumor cavity by bone cement with so far absence of any tumor recurrence documented by multiple histological sections at second look operation nine months after primary surgery, where cement has been replaced by autologous bone graft, and by subsequent follow-up.

Conclusions: PEComa is a very rare tumor, and its presence in bone is especially rare. The here reported case of PEComa presenting at the level of the talus is, to the best of our knowledge, the first case to be reported in the literature.     

Malignant perivascular epithelioid cell tumor in children: description of a case and review of the literature

Perivascular epithelioid cell tumors (PEComas) include different morphological entities originating from perivascular epithelioid cells. Their clinical behavior is not predictable, and there are no strict histologic criteria for malignancy, although larger tumors with infiltrative growth, hypercellularity, cellular atypia, atypical mitoses, and necrosis generally have a malignant course. Pediatric PEComas are rare, with less than 40 cases reported, mostly in children older than 5 years. We describe a case of malignant PEComa of the ligamentum teres in a 2-year-old girl, characterized by the occurrence of local relapse after primary treatment with chemotherapy and surgery and poor response to imatinib mesilate and temsirolimus used after further analyses confirmed p70S6K expression involved in the mTOR pathway. The girl was eventually treated with a debulking surgical procedure and is now alive with disease 6 years after diagnosis. Literature data of children affected by PEComas were also analyzed, trying to identify pathologic characteristics that could predict their course and therapeutic options. Histologically, they may be differentiated in 3 prognostic categories: (1) benign, lacking unfavorable morphological markers; (2) with uncertain malignant potential, carrying 1 unfavorable marker; and (3) malignant, with at least 2 unfavorable markers. In the literature, 9% of cases occurred as a second malignancy probably because of genomic instability related to treatment. Their different biology and the potential value of targeted therapies remain to be explored. The indolent evolution in our patient was similar to that reported in some other cases in the literature. In terms of treatment, the present case suggests a minor response to temsirolimus compared with the adult population.     

肝脏血管周上皮样细胞瘤一例

1临床资料 患者女,28岁.因背部疼痛6个月,彩色多普勒超声检查发现肝脏占位性病变2周于2011年7月26日入院.体格检查:皮肤、巩膜未见黄染,腹平软,无压痛及肌紧张,肝、脾肋下未触及.实验室检查:血、尿常规和血生化检查无异常;AFP 500 U/L,CEA 490 ng/L,CA19-96590 U/L,ICG R153％.     

Bladder perivascular epithelioid cell tumor: a novel rare neoplasm

Perivascular epithelioid cell tumors (PEComas) have recently been defined as a group of neoplasms that have in common the co-expression of melanocytic and smooth muscle markers. We report a novel case of a rare bladder PEComa and we review the relevant literature.     

Soft tissue epithelioid hemangioendothelioma: a case report

We report a case of epithelioid hemangioendothelioma observed in soft tissue in a 35-year-old man who presented a painful mass of the right arm which progressed in size for two years. Imaging revealed a 7-cm poorly limited expansive tumor process located in the medial muscle compartment of the right arm. Surgical resection was performed. Histological and immunohistochemical examination led to the diagnosis of soft tissue epithelioid hemangioendothelioma. The tumor recurred in the right arm and the right axillary fossa with development of multiple nodules in the contralateral thoracic wall and pleural effusion. Adjuvant chemotherapy and radiotherapy were performed, but the patient died at two years.     

肝血管周上皮样细胞肿瘤超声表现1例

患者男,81岁,体检超声发现肝脏占位2周;慢性乙型病毒性肝炎20年,未经系统治疗。查体未见异常。实验室检查:乙肝病毒表面抗原(+)、乙肝病毒e抗体(+)、乙肝病毒核心抗体(+),肝功能及肿瘤标记物均未见明显异常。上腹部CT:肝脏S5段(右肝前叶下段)见3.9 cm×2.7 cm低密度团块,边界清晰,增强扫描动脉期明显不均匀强化,门静脉期及延迟期轻度强化;CT诊断:肝脏S5段实性团块,恶性可能性大。     

Malignant PEComa: a case report with emphasis on clinical and morphological criteria

Background  

Malignant perivascular epitheliod cell tumor (PEComa) is a very rare entity composed of distinctive perivascular epitheliod cells with variable immunoreactivity for melanocytic and muscle markers. At present this neoplasm does not have a known normal cellular counterpart and the natural history is often unpredictable. Up to now, few cases of PEComa have been described and treatment modalities are still controversial, particularly in advanced conditions.     

Large osteoarthritic cyst presenting as soft tissue tumour - a case report

Large osteoarthritic cysts can sometimes be difficult to distinguish from primary osseous and soft tissue tumours. We present such a case involving a cyst arising from the hip joint and eroding the acetabulum which presented as a soft tissue malignancy referred to a tertiary bone and soft tissue tumour centre. We discuss the diagnostic problems it may pose, and present a literature review of the subject.     

肝脏血管周上皮样细胞肿瘤的临床及影像学特征

回顾性分析4例经病理证实的肝脏血管周上皮样细胞肿瘤(PEComa)患者影像资料,总结其影像特点并复习相关文献。4例患者均为体检发现,无乙肝病史。3例患者病变密度/信号均匀,1例病变密度/信号混杂,内见脂肪密度/信号。4例患者病变动脉期明显强化,2例包膜样延迟强化,3例强化特点呈快进快出。肝脏PEComa动脉期均为明显强...     

肝脏血管周上皮细胞瘤的诊断与外科治疗

目的 提高肝脏血管周上皮细胞瘤诊断与外科治疗水平.方法 回顾性分析我院腹部外科收治的14例肝脏血管周上皮细胞瘤的临床资料并进行随访.结果 14例患者中男性4例,女性10例,平均年龄46.3岁,均无肝炎病史,术前AFP均正常,肿瘤均为单发,直径5～17cm.14例患者均行手术切除,11例行肝肿瘤不规则切除术,3例行左半肝切除术.14例标本均无完整包膜,质软,边界清,免疫组化HMB45 (14/14)表达阳性.患者术后恢复良好,除2例失访外,无肿瘤复发.结论 肝脏血管周上皮细胞瘤无特异性临床症状,术前影像学检查难以确诊,肿瘤切除术是首选治疗方法,预后良好.     

泌尿系统血管周围上皮样细胞瘤家族的研究现状

血管周围上皮样细胞(PEC)是常见于血管周围上皮样细胞瘤家族(PEComas)的细胞,PEC表达肌源性和黑色素细胞标志物,如HMB45.目前PEComas的概念已被广泛接受,其发病与结节性硬化病(TSC)基因TSC1和TSC2基因变异有关.PEComas少见于泌尿系统,而且泌尿系统PEComas的组织来源、上皮样血管平滑肌脂肪瘤的定义以及PEComas良恶性的区分标准尚不确定,本文将对泌尿系统PEComas的研究现状作一综述.     

肝血管周上皮样细胞瘤的诊断与外科治疗

目的 总结肝血管周上皮样细胞瘤（PEComa）的临床特征,探讨该病的诊断与治疗方法.方法 回顾性分析2008年1月至2012年1月南京医科大学第一附属医院收治的16例肝PEComa患者的临床资料,总结该病的发病情况、临床特点、影像学特征、手术及病理检查情况.患者行部分肝切除术后定期复查腹部B超、肝功能和肿瘤标志物,必要时复查腹上区CT,了解肿瘤有无复发、转移.随访时间截至2012年12月.结果 16例患者中发病以中年女性患者居多,8例无自觉症状,其他患者表现为右季肋区不适、肝区隐痛或胀痛.肿瘤均为单发,位于肝右叶11例、肝左叶4例、肝尾状叶1例.术前B超检查无明显特异性征象,CT检查示肿瘤呈不均匀低密度表现.16例患者均行部分肝切除术,术后病理检查示均为R0切除,无手术并发症发生及患者死亡.免疫组织化学检测示16例患者上皮样肿瘤细胞中恶性黑色素瘤HMB-45、Melan-A和血管平滑肌肌动蛋白均呈阳性.16例患者均获随访,平均随访时间为27.9个月（9.0 ～46.0个月）,随访期内无肿瘤复发和死亡.结论 肝PEComa好发于中年女性患者,无特异性临床表现,术前CT检查有利于肝PEComa的鉴别诊断,行部分肝切除术治疗近期疗效良好.     

原发性腹膜后血管周上皮样细胞瘤合并肾错构瘤及结节性硬化1例报告并文献复习

目的 探讨原发性腹膜后血管周上皮样细胞瘤（PEComa）的临床病理特点及诊断治疗。方法 报告2009年4月北京协和医院基本外科诊治的位于盆腔的原发性腹膜后PEComa1例病人的症状、影像、病理、治疗及随访情况,并结合文献进行分析。结果 术前无特异临床症状,为查体发现。术前容易通过影像学手段发现但难以确诊。最终诊断依靠病理学表现和免疫组化。文献报道的原发性腹膜后PEComa非常罕见。结论 原发性腹膜后PEComa是一种非常罕见的间叶组织肿瘤,依靠病理学方法诊断。其生物学行为不明确,建议术后长期随访。     

肝脏血管周上皮样细胞肿瘤临床分析

目的 提高对罕见的肝脏原发性肿瘤——肝脏血管周上皮样细胞肿瘤(PEComa)的诊疗水平.方法 采用文献检索收集1989 ～ 2013年间报道的包括北京大学人民医院1例在内资料齐全的原发性肝脏PEComa患者41例,总结其病例资料,对原发性肝脏PEComa的临床特点、影像学资料、病理特点、治疗及预后进行回顾性分析.结果 肝脏PEComa无特异性临床表现,影像学特征不易识别,主要依靠术后病理确诊.手术是目前公认的主要治疗方法.41例患者中34例为良性,7例为恶性,恶性者预后较差.结论 原发性肝脏PEComa是一种肝脏罕见肿瘤,应提高对其认识和诊疗水平,术后应长期密切随访.