Malignant PEComa of the skull base

Perivascular epithelioid cell tumors (PEComas) are rare, usually benign lesions comprising a family of neoplasms including angiomyolipoma, lymphangioleiomyomatosis, clear cell "sugar" tumors, and clear cell myomelanocytic tumors. This report describes an apparent case of a malignant PEComa of the skull base in a 49-year-old woman, a previously undescribed location for this lesion.     

Recurrent renal epithelioid angiomyolipoma

Renal angiomyolipoma has traditionally been considered a benign tumor. Recently, a variety of epithelioid angiomyolipomas with malignant potential have been described. We report an adrenal recurrence in a patient who had a cellular angiomyolipoma removed 4 years earlier.     

Malignant hepatic angiomyolipoma: report of a case and review of literature

Hepatic angiomyolipoma, a constituent of the group of tumors showing differentiation resembling perivascular epithelioid cells, is primarily appreciated in its benign form. Regardless of their location, this family of tumors is characterized by the presence of mature adipocytes, blood vessels, and spindle-epithelioid cells. These tumors also possess similar immunohistochemical profiles, including positivity for melanocytic (HMB-45) and smooth muscle (smooth muscle actin) markers. Here, we present a case of malignant hepatic perivascular epithelioid cells that was initially confined to the liver, treated by resection, and subsequently recurred within and metastasized beyond the liver. We take this opportunity to report the fourth case of malignant hepatic angiomyolipoma (HAML) and review the literature. We will discuss the features that aid in distinguishing between benign and malignant HAML, and their similarities. In summary, the common features of both benign and malignant HAML include the following: the 3 basic histologic components of AML, expression of melanocytic and smooth muscle markers, invasion into adjacent normal parenchyma, and cytologic atypia. The unique features of malignant HAML are as follows: clinical evidence of aggressive behavior such as metastasis or death owing to disease, coagulative necrosis, and loss of CD 117 expression.     

Aggressive Angiomyolipomas: the Clandestine Epithelioid Variant

Epithelioid angiomyolipoma is a rare mesenchymal derived neoplasm of the kidney. Thought to be a variant of classical angiomyolipoma, a benign tumour, its malignant potential has been highlighted by case reports of loco-regional and distant metastasis. Given the potentially adverse clinical course associated with epithelioid angiomyolipoma compared to classical angiomyolipoma, the distinction and comprehensive histological characterisation of this rare entity is essential.Key Words: Angiomyolipoma, Computed tomography, Renal cell carcinoma     

Role of mammalian target of rapamycin inhibitor in the treatment of metastatic epithelioid angiomyolipoma: A case report

Epithelioid angiomyolipoma has malignant potential; however, no effective therapy has been established for advanced cases. A 50‐year‐old woman with a history of right nephrectomy for epithelioid angiomyolipoma was referred to our institution. Computed tomography and magnetic resonance imaging showed multiple tumors in her lung, liver and pelvic cavity. The liver and pelvic tumor specimens obtained by needle biopsy confirmed the diagnosis of epithelioid angiomyolipoma recurrence. The patient was treated with everolimus (10 mg/day). Three months later, pulmonary lesions disappeared; liver and pelvic tumors significantly shrank in size, but the pelvic tumor gradually enlarged again. We carried out surgical resection of the residual liver and pelvic cavity tumors. Although the mammalian target of rapamycin inhibitor seems to be effective for treating epithelioid angiomyolipoma, its long‐term effects remain unknown. Thus, aggressive administration of a multidisciplinary treatment including molecular target therapy and surgical resection is required to improve the prognosis of epithelioid angiomyolipoma.     

Renal angiomyolipoma with liposarcomatous transformation: a case report and review of the literature

Renal angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Sarcomatous transformation of the disease is exceedingly rare. We report the first case of a high grade round cell liposarcoma arising in a renal angiomyolipoma.     

Malignant epithelioid angiomyolipoma ('sarcoma ex angiomyolipoma') of the kidney: a case report and review of the literature

Malignant epithelioid angiomyolipoma is a recently described rare tumor of the kidney. Its existence has been questioned, however, on the basis of incomplete evidence of malignant behavior, the absence of an associated classic angiomyolipoma component, or the absence of immunoreactivity for HMB-45 in some cases. We describe a case that was HMB-45-positive and arose in association with a classic angiomyolipoma. The patient was treated with a partial nephrectomy. Three years later, she developed rapidly enlarging liver nodules. A fine-needle aspiration of the liver confirmed the presence of pleomorphic epithelioid cells morphologically and immunohistochemically identical to those comprising the primary renal tumor. After two cycles of treatment with doxorubicin, there was a 50% reduction in the size of the tumors with marked improvement in performance status. We believe this case confirms the existence of a malignant epithelioid angiomyolipoma.     

转移性恶性肾血管平滑肌脂肪瘤三例报告

目的 探讨转移性恶性肾血管平滑肌脂肪瘤(AML)的诊断和治疗. 方法转移性恶性AML患者3例.男1例,女2例.年龄分别为36、55和37岁.主诉为持续性患侧腰痛1～6个月.2例B超、CT检查发现患肾实性占位.1例B超见肾肿块内不均匀高回声光团,CT测得脂肪负值信号.2例行根治性肾切除术,1例行肾切除术.3例均未放化疗. 结果 肿块切面灰红、灰黄,质软.病理镜下观察:2例瘤细胞呈上皮样,核有异型,伴坏死;1例大多区域为梭形平滑肌,脂肪细胞和血管混杂生长,部分区域细胞呈上皮样.免疫组化结果 均为VM(+),HMIM5(+),Melan-A(+),S-100(-),CK(-).3例病理诊断均为恶性肾AML,2例为上皮样型,1例为经典型、部分上皮样型.1例术后7年出现肺转移,行肺叶切除加清扫,随访12年无瘤生存.1例术后6年复发,行肿块切除术;术后lO年发现肝、后腹膜转移,再行肿块部分切除,随访12年带瘤生存.1例术后4个月出现肝、后腹膜转移,行肿块部分切除,3个月后失访. 结论 恶性肾AML罕见,诊断依靠病理和免疫组化检查.治疗方法无特殊.     

Renal angiomyolipoma: a clinicopathologic, immunohistochemical, and follow-up study of 46 cases.

We reviewed 46 cases of renal angiomyolipoma covering the period from 1977 to 1997. Eight cases were associated with tuberous sclerosis and one with lymphangiomyomatosis. Histologically, the lesions were most often classic with the three usual components, i.e., mature adipose tissue, thick-walled blood vessels, and smooth muscle. Seven cases were particularly misleading: three cases were entirely adipose mimicking liposarcoma: two cases had an exclusively smooth-muscle component, one mimicking lymphangiomyomatosis and one with epithelioid cells; another case had a monophasic epithelioid pleomorphic component ("REON": renal epithelioid oxyphilic neoplasm) and proved to be fatal; and another case was associated with collecting duct carcinoma. The immunohistochemical profile showed the coexpression of alpha-smooth-muscle actin and HMB45. Our study is the first to show positivity of estrogen and progesteron receptors or both in more than 25% of cases. Of 35 cases with follow-up information, only one patient died of malignant spread of angiomyolipoma.     

Malignant transformation of renal angiomyolipoma: a case report

We report a case of renal angiomyolipoma (AML) with malignant transformation. A 28-year-old woman developed large bilateral renal masses 5 months before admission to our hospital. She was diagnosed with tuberous sclerosis when she was 4 years old. Total nephrectomy of the left kidney was performed, but she died during the operation. Although the focal region of the resected tumor had the appearance of a classic AML, most of the lesion showed a diffuse proliferation of atypical epithelioid cells resembling that in renal cell carcinoma. The epithelioid cells had extremely pleomorphic and hyperchromatic nuclei with frequent mitotic figures, including atypical forms. Immunohistochemical analysis revealed that the atypical epithelioid cells and the typical AML lesions were both positive for HMB-45 but that the former were negative for epithelial and myogenic markers. The smooth muscle cells and thick-walled vessels were focally positive for muscle-specific actins. Furthermore, the atypical epithelioid cells were immunoreactive for p53, whereas the foci of the typical AML were negative. Examination of the microdissected paraffin-embedded tissues revealed p53 mutations in the malignant epithelioid areas in AML but not in the renal parenchyma or typical AML areas. In this case it is proposed that p53 mutation may play an important role in malignant transformation of renal AML.     

Primary malignant gastric PEComa - Diagnostic and technical dilemmas

IntroductionThe World Health Organisation defines PEComa's as “a mesenchymal tumour composed of histologically and immunohistochemically distinctive perivascular cells”.¹ These ubiquitous tumours show distinctive perivascular epithelioid cell differentiation and arise most commonly at visceral and abdominopelvic sites.Presentation of caseWe present a case of a forty-two year old man presenting to accident and emergency department with upper gastro-intestinal bleeding. He had a palpable epigatric mass on examination. He underwent a CT Scan Abdomen which displayed a tumour arising from the gastric wall. Upper GI endoscopy and biopsy was carried out and biopsied were taken for histological analysis. A primary gastric PEComa was diagnosed and the patient underwent distal polya gastrectomy and gastrojejunostomy. This is believed to be the first reported case of a Primary malignant gastric PEComa.DiscussionPerivascular epithelioid carcinomas were first described in 1943 as an abnormal myoblast in a case of renal angiomyolipoma. PEComas display a strong female predominance with a typical benign course. There are approximately 100 reported cases of PEComa to date, with 55 of which were malignant. PEComa's may be subdivided into benign, uncertain malignant potential and malignant. Their natural history can be very aggressive leading to multiple metastases and death as expected with a high-grade sarcoma.ConclusionThis case depicts the aggressive nature of malignant gastric PEComa's. The majority of PEComa's are benign in nature and have a better prognosis. We display here the challenges in ascertaining a definitive diagnosis and management of such patients due to limited clinical studies.     

Hepatic angiomyolipoma: Two case reports of caudate-based lesions and review of the literature

Two case reports of hepatic angiomyolipoma, both originating in the caudate lobe, are reported with a review of the literature. The liver is the second most common site of angiomyolipoma, an uncommon benign tumor of mixed mesenchymal origin. It is commonly diagnosed following abdominal pain or as an asymptomatic mass discovered on abdominal ultrasound or computed tomography scan. Of 74 cases reported, the lesions ranged from 0.3 to 36 cm in diameter and are noted between the first and eighth decade, with predominant female predilection. The right lobe is the most common site, with lesions arising in the caudate lobe comprising only five cases. The natural history of the hepatic lesion is unknown. Malignant invasion or metastatic disease has not been documented. Hepatic and renal angiomyolipoma can occur concurrently (13 of 60 cases), although the majority are not biopsy proven. Multicentric hepatic disease occurs. The correlation between tuberous sclerosis and hepatic angiomyolipoma is not confirmed histologically and occurs rarely. These lesions have a characteristic radiographic appearance due to high fat content. Histologically, angiomyolipoma are characterized by an admixture of adipose tissue, blood vessels, and smooth muscle cells. These lesions cannot reliably be differentiated from a malignant lesion based on clinical history, radiologic examination, and/or pathologic interpretation. If clinical suspicion for malignancy is low, then careful observation with serial radiologic follow-up is performed. The treatment for a symptomatic or suspicious lesion is resection, if feasible. Liver transplantation may be considered for large or centrally located lesions not amenable to resection. (Liver Transpl Surg 1997 Jan;3(1):46-53)     

Renal epithelioid angiomyolipoma: 2 Cases report

Introduction

The 2004 World Health Organization Classification of Renal Neoplasms defined epithelioid angiomyolipoma as a potentially malignant mesenchymal neoplasm, characterized by a proliferation of predominantly epithelioid cells with approximately one third of patients experiencing metastases and one half of them having a history of tuberous sclerosis complex.

Malignant transformation of angiomyolipoma.

Angiomyolipomas are well recognized but uncommon tumors that can involve the kidney. To our knowledge a well documented case of malignant change of angiomyolipoma has never been reported. We report a case of renal angiomyolipoma and leiomyosarcoma with a clearly identified transition of benign to malignant elements seen in the resected tissue.     

肾上皮样血管平滑肌脂肪瘤诊治探讨

目的 提高肾上皮样血管平滑肌脂肪瘤(EAML)的诊治水平.方法 肾EAML患者5例.男3例,女2例.平均年龄46(26～64)岁.患侧腰部胀痛3例,体检偶然发现2例.肿瘤直径2.9～10.1 cm.B超和CT检查诊断为血管平滑肌脂肪瘤2例,肾癌、肾上腺肿瘤、肝癌各1例.行肾肿瘤剜除术3例,肾楔形切除术1例,肾切除术1例.结果 病理报告:肿瘤由不同比例的异常厚壁血管、平滑肌和脂肪组织构成.上皮样细胞胞质浓密嗜酸性或透亮,有嗜酸性颗粒,并有丰富的血管,上皮样细胞簇常围绕血管.组织学形态表现为圆形、多边形和梭形上皮样细胞灶性分布于脂肪瘤中,上皮样瘤细胞免疫组化标记SMA、Vimentin、HMB45表达阳性.5例病理诊断均为肾EAML.随访2～12个月,未见局部复发及远处转移.结果 肾EAML由厚壁血管、脂肪和平滑肌细胞混合组成,上皮样细胞簇常围绕血管.确诊依赖于临床、影像学及病理学检查相结合,免疫组织化学染色有助于诊断及鉴别诊断.早期诊断及完整切除肿瘤是治疗关键.     

Expression of telomerase reverse transcriptase (TERT) in malignant mesotheliomas

To evaluate the usefulness of determinations of telomerase activity for distinguishing malignant from benign mesothelial lesions, immunohistochemical (using a rabbit polyclonal antibody and the peroxidase method; n = 68) and in situ hybridization (using sense and antisense oligonucleotide probes; n = 46) studies were made on malignant mesotheliomas (epithelioid, 39; sarcomatoid, 18, including 2 of the desmoplastic type; and biphasic, 11) and 19 benign mesothelial lesions (benign mesothelial hyperplasia, 3; and reactive pleuritis, 16). In addition, biochemical studies of telomerase activity were made in 9 of the malignant mesotheliomas. Telomerase activity was detected histochemically in all but one of the malignant mesotheliomas, but only in one (pleuritis) of the benign lesions, in which it was present only in activated lymphocytes. Antisense hybridization signals indicated the presence of telomerase mRNA mainly in the cytoplasm of the malignant cells. Sense probes gave negative results. Biochemical determinations revealed a strong telomerase activity in the 9 malignant mesotheliomas examined. This study demonstrates the usefulness of immunohistochemical staining for the evaluation of mesotheliomas. The required immunostaining can be performed using paraffin sections of formalin-fixed tissues.     

Surgeon-controlled robotic partial nephrectomy for a rare renal epithelioid angiomyolipoma using near-infrared fluorescence imaging using indocyanine green dye: A case report and literature review

Renal epithelioid angiomyolipoma (E-AML) is a rare variant of angiomyolipoma (AML). It is a mesenchymal tumour believed to originate from the perivascular epithelioid cell (PEC). Unlike conventional AML which are benign, E-AML has a rare aggressive behaviour. Conventional AML is typically triphasic containing adipose tissue, smooth muscle and dystrophic vessels in variable proportions, while E-AML are generally composed of plump spindled and polygonal-shaped “epithelioid cells” showing clear or eosinophilic cytoplasm and occasional pleomorphic multinucleated giant cells. E-AML can be misdiagnosed as renal cell carcinoma (RCC) when these “epithelioid cells” show clearing. Only a small number of cases of E-AML have been reported with the standard treatment being radical or partial nephrectomy. We report the first case report of a surgeon-controlled robotic partial nephrectomy using a near-infrared fluorescence imaging using indocyanine green dye on a 25-year-old woman with a T1B (6.6 cm) right renal mass. The final pathology revealed the diagnosis of E-AML. There was no recurrence and metastases after the 6-month follow-up.     

Renal epithelioid angiomyolipoma associated with hyperprolactinemia

We report a unique case of a 42-year-old woman with a renal epithelioid angiomyolipoma associated with elevated serum prolactin levels and presenting with galactorrhea. Magnetic resonance imaging of the brain showed no pituitary abnormality, and abdominal imaging demonstrated a large right renal mass. Pathologic analysis of the radical nephrectomy specimen revealed an epithelioid angiomyolipoma. She had an uneventful postoperative recovery with complete normalization of her serum prolactin level and resolution of galactorrhea. To our knowledge, the association between epithelioid angiomyolipoma and hyperprolactinemia has never before been reported.     

肾上皮样血管平滑肌脂肪瘤临床特点分析

目的 探讨肾上皮样血管平滑肌脂肪瘤的临床及病理特点.方法 肾上皮样血管平滑肌脂肪瘤患者6例.单发4例,多发2例.肿瘤直径平均9(5～14)cm.有结节硬化家族史1例.CT检查发现肿瘤内含脂肪组织(CT值-30～-120 HU)3例,诊断为肾血管平滑肌脂肪瘤;3例瘤组织CT值30～55 HU,增强扫描CT值70～110 HU.行肿瘤剜除术3例,行根治性肾切除术3例.结果 3例行肿瘤剜除术者肿瘤完整剜除,2例出现肾盂破损,行肾盂修补及留置双J管.其中1例双肾肿瘤者,2个月后手术剜除对侧肿瘤.3例根治性肾切除者完整切除肾脏、肾周脂肪组织及肿大淋巴结.病理检查:镜下肿瘤以上皮样细胞为主,并出现多形、异形核,有明显的上皮样分化,浸润破坏性生长,瘤组织广泛坏死.免疫组化染色HMB45(+++),EMA、CK(-).病理诊断均为肾上皮样血管平滑肌脂肪瘤.平均随访26(10～44)个月,肿瘤无复发及转移5例;1例根治术后18个月出现双肺转移,10个月后死亡.结论 肾上皮样血管平滑肌脂肪瘤多为良性,部分缺乏脂肪组织,主要由单核或多核的上皮样细胞构成,免疫组化染色HMB45强阳性为特征表现,具有潜在恶性倾向,可发生转移;CT检查易误诊为肾癌;手术为主要治疗方法.