肾上皮样血管平滑肌脂肪瘤肺转移1例报告并文献复习

目的：探讨肾上皮样血管平滑肌脂肪瘤病理特点及生物学行为。方法：对1例低热患者行肺肿块穿刺活检,然后行HE染色和免疫组织化学染色。复习肾肿瘤病理切片并进行文献复习。结果：穿刺活检病理分析：密集分布的上皮样细胞,细胞体积大,呈圆形、多边形;异型明显;无血管平滑肌脂肪瘤结构;免疫组织化学：人黑色素瘤蛋白阳性,平滑肌肌动蛋白阳性,上皮膜抗原阴性。病理诊断：左肺上皮样血管平滑肌脂肪瘤;考虑来源于肾。结论：上皮样血管平滑肌脂肪瘤是一种有恶性潜能的间叶性肿瘤,可以发生远处转移。     

Angiomyolipoma of the liver and lung: a case explained by the presence of perivascular epithelioid cells

We report a case of synchronous hepatic and pulmonary angiomyolipoma not associated with tuberous sclerosis or renal angiomyolipoma. The liver tumor contained tortuous vessels, smooth muscle tissue, and fat. It was partially necrotic and made up of pleomorphic epithelioid smooth muscle cells. Positivity for HMB-45 confirmed the diagnosis of angiomyolipoma. Lung biopsy showed multiple abnormal proliferation of smooth muscle cells exhibiting spindle-shaped or epithelioid morphology. The tumor grew around the vessels, and the cells were positive for HMB-45. The occurrence of this case could be explained by a simultaneous proliferation of perivascular epithelioid cells. To the best of our knowledge, this is the first case of hepatic angiomyolipoma associated with multiple pulmonary angiomyolipomas, mimicking hepatic tumor lung metastases on X-ray examination.     

Epithelioid angiomyolipoma: appearance on fine-needle aspiration report of a case

Epithelioid angiomyolipoma is a recently recognized clinicopathologic entity first described by Martignoni et al. in 1995. Since then, several articles have further clarified its histogenesis and histologic features. Due to the presence of polygonal cells with voluminous cytoplasms, this neoplasm is often mistaken for renal-cell carcinoma. In this case presentation, we describe the cytologic features of an epithelioid angiomyolipoma obtained by fine-needle aspiration. The histogenesis and how it relates to diagnosis is briefly discussed. The importance of ancillary techniques in the differential diagnosis of epithelioid cells obtained in a renal aspirate is reviewed.     

A hepatic tumor associated with bilateral renal angiomyolipomas: A variant of angiomyolipoma?

Angiomyolipoma is usually derived from the kidney and composed of well developed vessels, smooth muscle and fat tissue. The liver is the only extra-renal site of angiomyolipoma. A peculiar type of hepatic tumor accompanied by bilateral renal angiomyolipomas is reported here. The tumor was mostly composed of large epithelioid cells and a small part of hyalinized large vessels and foam cell infiltration. Mature adipose tissue was absolutely absent. Epithelioid tumor cells arranged in an alveolar pattern had abundant glycogen and some diastase-resistant periodic acid-Schiff granules without obvious crystals. Immunohistochemical studies revealed that the epithelioid cells were positive for melanoma specific antibody (HMB-45), S-100 protein, aromatic L-amino acid decarboxylase and focally a-smooth muscle actin. Many melanosome- or premelanosome-like, electron-dense granules were observed in these cells. Thus, these cells were characterized by differentiation to both immature melanocytes and smooth muscle ceils. These epithelioid cells were similar to some cells in the renal angiomyolipomas of the same patient. The hepatic tumor was considered to be a result of monotonous proliferation of the epithelioid cells seen in renal angiomyolipoma. Differential diagnosis of this tumor was discussed.     

Epithelioid angiomyolipoma of the kidney: case report

Renal angiomyolipoma is a benign tumour histologically characterized by a mixture of adipose tissue, smooth muscle cells and thick walled blood vessels. Long-believed to be a benign hamartoma, angiomyolipoma is now considered to arise from perivascular epithelioid cells. Epithelioid angiomyolipoma is a rare type of angiomyolipoma, composed partially or completely of epithelioid cells, with a potentially aggressive behaviour. Histologically it can mimic renal cell carcinoma. Positivity for HMB45, Melan A, CD68 and CD117 are useful for diagnosis. Herein, we report the clinicopathologic and immunohistochemical features of a renal tumour composed of large epithelioid mononucleated or multinucleated cells with abundant acidophilic cytoplasm and prominent nucleoli. Despite the morphologic resemblance of this tumour to renal cell carcinoma, its phenotype (HMB45, Melan A and CD68 positivity and keratin negativity) parallels the phenotypic profile of angiomyolipoma. Therefore, immunohistochemistry should be considered when diagnosing this variant of angiomyolipoma.     

Nuclear pseudoinclusions in fine-needle aspiration cytology of hepatic angiomyolipoma: case report

A nodular lesion was found in the fourth segment of the liver in a 51-yr-old Caucasian woman and subjected to aspiration cytology. Smears exhibited solid sheets or small aggregates of epithelioid cells with numerous nuclear pseudoinclusions, scanty mature adipocytes, and red blood cells. With a presumptive diagnosis of angiomyolipoma, the patient underwent laparotomy with resection of the nodule; histologic and immunohistochemical findings confirmed the diagnosis, identifying the trabecular variant. Although the presence of nuclear pseudoinclusions has been previously reported in renal angiomyolipomas, this cytologic feature has not received adequate attention in liver localization, where only cell block samples have been reported. Therefore, when the typical different cellular components of angiomyolipomas are absent in cytologic smears, nuclear pseudoinclusions should not be regarded as a criterion of malignancy, but they may be considered as an additional nonspecific cytological feature in hepatic angiomyolipoma.     

Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum

BACKGROUND: Renal angiomyolipoma is a benign tumor histologically characterized by proliferation of spindle cells, epithelioid cells, and adipocytic cells in concert with many thick-walled blood vessels. To add further diagnostic confusion, an epithelioid cell-predominant variant of renal angiomyolipoma has recently been described. HMB-45 immunoreactivity correlates with ultrastructural striated organelles that closely resemble premelanosomes, although no evidence of melanogenesis has been documented in this tumor. OBJECTIVE: To further characterize the immunophenotypic and ultrastructural profile of renal angiomyolipoma based on phenotypic cell type (epithelioid, spindle, and adipocytic cell). DESIGN: Formalin-fixed, paraffin-embedded tissues from 27 renal angiomyolipomas and 8 renal cell carcinomas were immunostained with monoclonal antibodies to the melanoma-associated antigens HMB-45, HMB-50, NKI/C3 (CD63), and tyrosinase; the smooth muscle-related antigens calponin and muscle-specific actin (HHF-35); S100; and cytokeratin (CK). All renal angiomyolipomas were also immunostained with a polyclonal antibody to renin. Ultrastructural examination was performed on 9 selected cases. RESULTS: All renal angiomyolipomas stained positive for HMB-45, HMB-50, NKI/C3, muscle-specific actin (HHF-35), and calponin. Overall, HMB-45, HMB-50, and NKI/C3 preferentially stained the epithelioid cells. Tyrosinase staining was present in 50% of the renal angiomyolipomas with adequate tissue for staining (12 of 24 cases); positive staining and intensity paralleled HMB-45, HMB-50, and NKI/C3. Muscle-specific actin (HHF-35) and calponin preferentially stained the spindle cells. The adipocytic cells stained positive for both melanoma-associated antigens and smooth muscle antigens. Epithelioid cells, spindle cells, and adipocytic cells were CK, S100, and renin negative. Ultrastructural findings paralleled immunohistochemical staining patterns. Premelanosome-like organelles and electron dense granules were more readily detected in the epithelioid cells within the tumor, whereas ultrastructural characteristics of smooth muscle cells were more easily found in the spindle cells. All renal cell carcinomas stained positive for CK, NKI/C3 staining was variable, and all were negative for HMB-45, HMB-50, smooth muscle actin (HHF-35), and calponin. CONCLUSION: In renal angiomyolipoma, the epithelioid and spindle cells have preferential staining patterns for melanoma-associated antigens versus smooth muscle antigens, respectively. Positivity in renal angiomyolipoma for HMB-50, NKI/C3, and tyrosinase, in addition to HMB-45, provides evidence for the presence of different melanoma-associated gene products. Immunophenotypic overlap of the 3 histologically distinct renal angiomyolipoma cell populations suggests a common cell line, supporting a unitarian concept for renal angiomyolipoma. Ultrastructural characteristics of the 3 renal angiomyolipoma cell phenotypes parallel the immunophenotype, giving further support to a common cell line. Our study lends further credence to the perivascular epithelioid cell concept as proposed by Bonetti and colleagues.     

Monotypic epithelioid angiomyolipoma of the liver

AIMS: Monotypic epithelioid angiomyolipoma is a recently recognized renal tumour, which is composed purely of epithelioid cells coexpressing markers of both smooth muscle differentiation and melanogenesis (HMB45). We report here the first case of monotypic epithelioid angiomyolipoma arising in the liver. CASE DETAILS: A 30-year-old woman without tuberous sclerosis complex (TSC) was incidentally found to have a hepatic mass by ultrasonography. Grossly, the resected tumour showed a nodule-in-nodule appearance, with large areas of haemorrhagic necrosis. Microscopically, the tumour was composed of pleomorphic epithelioid cells with clear, eosinophilic cytoplasm. Neither adipocytes nor abnormal vessels were recognized in the tumour. Immunohistochemically, the tumour cells were strongly positive for HMB45 and S100 protein, focally positive for desmin, vimentin and smooth muscle actin, and negative for epithelial markers (cytokeratins, EMA). Ultrastructural analysis showed numerous dense granules with some striated ones resembling melanosomes, myofilaments and pinocytic vesicles in the cytoplasm. Molecular analysis showed no allelic loss of the TSC2 region or 12 other chromosomal regions. The patient is free of disease over 1 year after the operation. CONCLUSION: We consider that this hepatic tumour is closely related to angiomyolipoma, and a counterpart of renal monotypic epithelioid angiomyolipoma.     

Epithelioid angiomyolipoma: a morphologically distinct variant that mimics a variety of intra-abdominal neoplasms

This review examines the histopathologic, immunohistochemical, ultrastructural, and molecular biologic features of epithelioid angiomyolipoma (EAML), with an emphasis on the differential diagnosis of intra-abdominal EAML. Epithelioid angiomyolipoma is an uncommon mesenchymal tumor with malignant potential, frequently associated with tuberous sclerosis complex. Histologically, EAML is characterized by sheets or nests of large polygonal epithelioid cells with abundant eosinophilic or occasionally clear cytoplasm, often with prominent nucleoli, and EAML may include multinucleated and markedly pleomorphic forms. As these tumors share a distinctive perivascular epithelioid cell phenotype, they belong to the PEComa tumor family. Nearly all EAMLs show immunoreactivity for both melanocytic and myoid markers. Ultrastructurally, EAMLs show evidence of melanogenesis by the presence of premelanosomes. Epithelioid angiomyolipoma can pose significant diagnostic challenges as it mimics morphologically a variety of neoplasms including renal cell carcinoma, renal oncocytoma, adrenal cortical neoplasm, epithelioid smooth muscle tumor, epithelioid peripheral nerve sheath tumor, epithelioid gastrointestinal stromal tumor, epithelioid melanoma, hepatoblastoma, and hepatocellular carcinoma. The variation in immunophenotype in these tumors requires a prudent use of immunohistochemistry, which may occasionally need complementation by electron microscopy to establish the correct diagnosis.     

HEPATIC ANGIOMYOLIPOMA

Hepatic angiomyolipoma in a 59-year-old woman Is reported. The tumor was located at the lower edge of the left lobe of the liver, measured 3 × 2 × 2 cm, and appeared solid. Histologically, It consisted of abundant blood vessels of varying caliber, mature fat cells, and round, spindle-shaped or epithelioid interstitial cells. The latter were considered to be of smooth muscle origin, because myofilamentous structures were demonstrated ultrastructurally in the cytoplasm and because they were positive for desmin by the PAP method. Based on these findings, the diagnosis of angiomyolipoma was confirmed. A review of the literature revealed only 15 cases of hepatic angiomyolipoma. From a clinlcopathological viewpoint, a comparison was made between hepatic angiomyolipoma and its more frequent renal counterpart. The hepatic tumor is considered to be a kind of hamartoma.     

Hepatic angiomyolipoma. A case report with review of the literature

Hepatic angiomyolipoma in a 59-year-old woman is reported. The tumor was located at the lower edge of the left lobe of the liver, measured 3 x 2 x 2 cm, and appeared solid. Histologically, it consisted of abundant blood vessels of varying caliber, mature fat cells, and round, spindle-shaped or epithelioid interstitial cells. The latter were considered to be of smooth muscle origin, because myofilamentous structures were demonstrated ultrastructurally in the cytoplasm and because they were positive for desmin by the PAP method. Based on these findings, the diagnosis of angiomyolipoma was confirmed. A review of the literature revealed only 15 cases of hepatic angiomyolipoma. From a clinicopathological viewpoint, a comparison was made between hepatic angiomyolipoma and its more frequent renal counterpart. The hepatic tumor is considered to be a kind of hamartoma.     

Epithelioid angiomyolipoma of kidney with atypical nuclear features and intranuclear inclusions on cytology

Described herein are the cytological findings of epithelioid angiomyolipoma (EAML) of the kidney with atypical nuclear features mistaken for renal cell carcinoma (RCC) in a 61‐year‐old male patient. Aspirates from this large renal mass were cellular and showed epithelioid cell clusters with focally crowded nuclei showing moderate anisonucleosis, small nucleoli, and prominent eosinophilic intranuclear inclusions. Failure to recognize the scanty adipose tissue component and preponderance of epithelioid cells with nuclear pleomorphism lead to a diagnosis of RCC on cytology. On histology, the tumor was essentially composed of epithelioid and spindle cells that showed the typical immunoprofile of an angiomyolipoma and only occasional foci of typical AML were seen. The hilar lymph node was involved in contiguity. However, in view of lack of obvious features of malignancy, the tumor was labeled as EAML with atypical features. Immunocytochemistry on the destained cytology aspirates revealed strong smooth muscle actin staining of all cells. To conclude, EAML can mimic a RCC. In such instances, lack of arborizing vasculature, absence of cytoplasmic fatty vacoulation, crowded nuclei with intranuclear inclusions, and lack of prominent nucleoli along with typical immunophenotype of EAML may assist in the cytology diagnosis. Diagn. Cytopathol. 2011;39:278–282. © 2010 Wiley‐Liss, Inc.     

肾脏上皮样血管平滑肌脂肪瘤的病理观察

目的对肾脏上皮样血管平滑肌脂肪瘤（epithelioid agiomyolipoma,EAML）的病理诊断、鉴别诊断和预后进行分析。方法2例肾脏EAML（其中1例为复发病例）,复习其临床资料,病理学检查包括常规病理学、免疫组织化学和超微结构,并进行随访。结果光镜下肿瘤均主要由具有多形性和不典型性的上皮样细胞组成,部分区域有明显的血管周上皮样排列;可见出血和坏死;并可见静脉内瘤栓;淋巴结内可见上皮样肿瘤细胞累及。免疫组织化学肿瘤细胞（包括淋巴结内肿瘤）HMB45、平滑肌肌动蛋白（SMA）、神经元特异性烯醇化酶（NSE）和波形蛋白弥漫阳性;S-100、melanpan和CD68散在阳性;而上皮细胞膜抗原（EMA）、AE1／AE3、CK7、CD117、肌肉特异性肌动蛋白（MSA）、结蛋白、白细胞共同抗原（LCA）、CD20、CIM5RO、CD30、CD15、嗜铬素（CgA）、突触素（Syn）、bcl-2、雌孕激素受体（ER、PR）和p53均为阴性。电镜检查可见一些肿瘤细胞内有黑色素小体样的致密颗粒、肌丝、密体,肿瘤细胞外可见不连续的基膜。2例患者手术后10个月状态良好,无肿瘤局部复发和转移征象。结论血管周上皮样排列、寻找经典血管平滑肌脂肪瘤的结构和肿瘤细胞表达HMIM5和SMA对于诊断和鉴别诊断至关重要。而细胞的不典型性、出血坏死和核分裂象可能只表明肿瘤的恶性潜能：淋巴结受累、肾静脉瘤栓不是恶性的诊断依据：只有远处转移才是恶性的证据。     

Angiomyolipoma of the kidney: expanding disease spectrum demonstrated by 3 cases.

We report 3 recent cases of angiomyolipoma of the kidney. Although generally regarded as a benign neoplasm, angiomyolipoma rarely behaves in an aggressive manner, producing complicated clinical courses leading to metastasis and death. The presence of epithelioid elements within the tumor can result in difficulty differentiating benign from malignant angiomyolipoma and differentiating this tumor from renal adenocarcinoma. The presence of lymph node involvement can cause difficulty in differentiating multicentric disease in lymph nodes from metastasis to lymph nodes. The presence of cytologic abnormalities in the primary tumor can result in difficulty in differentiating atypia in benign angiomyolipoma from malignant sarcomatous transformation of a benign lesion. The 3 cases reported show many of these problems. Criteria for predicting malignancy in epithelioid tumors and sarcomatous transformation are not well recognized because of the rarity of this entity. The typical immunophenotype of all types of angiomyolipoma (cytokeratin-negative and melanomarkers-positive) is very useful in diagnosis but does not help in the differentiation from renal adenocarcinoma at frozen section. We report the empiric use of Ki67 and p53 in these cases as adjuncts to clinical and histologic assessment in predicting behavior. High Ki67 expression was a feature of malignant epithelioid angiomyolipoma. Low levels of p53 expression were seen in the angiomyolipoma with sarcomatous transformation. Benign angiomyolipomas were consistently negative for both Ki67 and p53.     

肾脏上皮样色素性透明细胞肿瘤病理形态观察

目的 探讨上皮样色素性透明细胞肾脏肿瘤形态学特点,加强对该肿瘤的认识,减少误诊.方法 回顾性分析2000余例肾脏肿瘤,符合上皮样色素性透明细胞肿瘤3例,通过HE、免疫组织化学EnVision法观察3例肿瘤形态学特点,对其中1例行超微结构观察,同时复习相关文献.结果 女性2例,男性1例,2例形态学表现为透明细胞癌样,1例见透明细胞和嗜酸性细胞构成乳头结构.免疫组织化学上皮标记及S-100蛋白均为阴性,HMB45均为阳性,2例Melan A阳性.电镜末见黑色素小体结构.结论 色素性透明细胞上皮样肿瘤是非常罕见的肾脏肿瘤,病理学特征兼有肾细胞癌、上皮样血管平滑肌脂肪瘤与黑色素瘤等肿瘤特征,免疫组织化学有利于鉴别诊断.其可能是上皮样血管平滑肌脂肪瘤的一种亚型.     

Angiomyolipoma of the bladder

Angiomyolipoma of the bladder is an extremely rare neoplasm. We report a case of a 55-year-old woman with an angiomyolipoma of the bladder visualized on pelvic sonogram as a 5 mm polyp in the floor of the bladder. The lesional tissue consisted of spindle cells, epithelioid cells, and adipocytes, with occasional thick-walled blood vessels. Immunohistochemical studies showed the spindle and epithelioid cells to be focally positive for HMB-45 and diffusely positive for actin and muscle cell antigen (HHF-35), which confirmed the diagnosis of angiomyolipoma. A review of the recent literature on the pathogenesis of angiomyolipoma follows.     

Clinicopathologic features of renal epithelioid angiomyolipoma: report of one case and review of literatures

Epithelioid angiomyolipoma (EAML) is a rare renal mesenchymal tumor with malignant potential and is frequently associated with tuberous sclerosis complex (TSC). As metastasis of the tumor cells occur early, EAML is considered a potentially malignant tumor type and intrigues further research on it. Under the microscope, we could find the tumor was composed of atypical polygonal cells sheet mixed with classic angiomyolipoma (AML) components such as blood vessels with notable thick vascular walls, smooth muscle-like cells and adipocytes. Immunohistochemical studies showed that epithelioid cells were focally positive for vimentin, melanocytic markers (HMB-45), myoid markers (α-smooth muscle actin), CD34 and CD68; negative for cytokeratin, epithelial membrane antigen, CD10, and S-100. And the Ki67 index showed approximately 3%. Here, we report the morphological and immunohistochemical features of clinically or histologically malignant renal EAML and discuss its diagnosis, differential diagnosis and the prognosis.     

Hepatic epithelioid angiomyolipoma with trabecular growth pattern: a mimic of hepatocellular carcinoma on fine needle aspiration cytology

Epithelioid angiomyolipomas (AMLs) of the liver are rare tumors with imaging and cytologic features overlapping with those of hepatocellular carcinomas. We report the fine needle aspiration and core biopsy findings of an epithelioid AML in the right hepatic lobe of a 32-year-old female with tuberous sclerosis. She had undergone renal transplantation 8 years previously after bilateral nephrectomy for renal AMLs and a 3-cm chromophobe renal cell carcinoma. Hepatocellular carcinoma was suspected during the initial cytologic and histologic examination based on the presence of numerous large polygonal cells with ample finely vacuolated or granular cytoplasm, low nucleocytoplasmic ratio, and mild nuclear pleomorphism in the smears, as well as a distinctive trabecular histologic pattern in the core biopsies. Immunoperoxidase stains showed that the neoplastic cells were negative for cytokeratins and positive for HMB45, Melan-A, and smooth muscle actin, establishing the diagnosis of epithelioid AML. To determine the distinguishing cytomorphologic features between epithelioid AML and HCC, we have compared the cytologic features of 15 cases of hepatic AML reported in the literature, including the present case, to the FNA cytologic findings of 38 consecutive cases of HCC diagnosed at out institution.     

Epithelioid angiomyolipoma of the kidney: a case report

Renal angiomyolipoma is a distinctive benign neoplasm that occurs either sporadically or in patients with tuberous sclerosis complex. A 45-year-old woman was admitted with history offlank pain and vomiting. There were no signs suggestive of tuberous sclerosis either in the patient or her family. At operation, she had a left renal mass with nephrolithiasis and hydronephrosis. Histopathology revealed epithelioid angiomyolipoma of the left kidney with chronic pyelonephritis. Immunohistochemistry confirmed the diagnosis of angiomyolipoma. This case is presented to highlight the epithelioid variant of angiomyolipoma which may behave in an aggressive manner.     

Abdominopelvic sarcoma of perivascular epithelioid cells. Report of four cases in young women, one with tuberous sclerosis.

The perivascular epithelioid cell has been proposed to be the unifying proliferating cell type in a number of lesions such as angiomyolipoma, lymphangiomyomatosis, clear cell "sugar" tumor and renal capsuloma. With the exception of rare examples of angiomyolipoma, they are non-metastasizing. We report four examples of a new member of this family of perivascular epithelioid cell neoplasms that occur in abdominopelvic location and show metastatic properties. The patients, all women, were aged 19 to 41 years (mean, 32), and presented with a tumor mass involving the serosa of the ileum, uterus or pelvic cavity. Morphologically, the tumors were composed of sheets of large polygonal cells with glycogen-rich clear or eosinophilic cytoplasm and moderately pleomorphic nuclei, traversed by a delicate vasculature, mimicking clear cell carcinoma. There were areas of coagulative necrosis and occasional mitotic figures. Intracytoplasmic brown pigment was present in two cases. Spindly cells, smooth muscle and fat were absent. Lymphovascular invasion was present in all, lymph node metastasis was documented in two and metastasis to the ovary was present in one case. Two patients developed widespread metastatic disease after 10 and 28 months from diagnosis. One patient showed the clinical signs of tuberous sclerosis. In spite of the epithelial-like appearance, the tumor cells were negative for epithelial markers but were strongly positive with the melanogenesis-related marker HMB45. Another melanogenesis marker (MART-1) was positive in two cases. Other markers including S-100 protein, vimentin, muscle-specific actin, desmin and chromogranin A were negative. Thus, these tumors are not readily classifiable in the existing schema of known entities, and show overlapping morpho-phenotypic features of clear cell "sugar" tumor of the lung and epithelioid angiomyolipoma. We consider them as sarcomas composed of a pure population of uncommitted perivascular epithelioid cell, that lack modulation toward smooth muscle or adipose cells.