肝脏单形性上皮样血管平滑肌脂肪瘤

目的：探讨肝脏单形性上皮样血管平滑肌脂肪瘤的临床病理学特征及诊断、鉴别诊断要点。方法：对1例单形性上皮样血管平滑肌脂肪瘤进行临床病理学分析及免疫组织化学研究。结果：肝脏单形性上皮样血管平滑肌脂肪瘤临床多无症状,光镜下单形性上皮样血管平滑肌脂肪瘤由形态多样的上皮样细胞构成,胞质透明或嗜酸,无脂肪组织及异常血管;免疫表型;HMB45阳性,SMA及vimentin部分阳性,desmin少数阳性,S－100蛋白弱阳性,cytokeratin及AFP阴性,CD34血管内皮细胞阳性。结论：肝脏单形性上皮样血管平滑肌脂肪瘤是极为罕见的间叶性肿瘤,组织起源至今不明,其诊断及鉴别诊断主要依靠病理组织学及免疫组织化学。     

上皮样血管平滑肌脂肪瘤6例临床病理分析

目的 探讨上皮样血管平滑肌脂肪瘤(epithelioid angiomyolipoma,EAML)的临床病理特点、免疫表型,诊断及鉴别诊断.方法 对5例肾脏和1例肝脏上皮样血管平滑肌脂肪瘤进行病理形态观察及免疫组织化学检测.结果 6例上皮样血管平滑肌脂肪瘤形态相似,肿瘤细胞多呈巢状和片状排列,围绕血管呈袖套状,瘤细胞体积大,形态单一,多边形或梭形,胞质丰富,嗜酸性颗粒状,细胞核较大,核仁明显呈空泡状.免疫组化显示肿瘤细胞HMB45、vimentin 和平滑肌特异性抗原(SMA,MSA)弥漫阳性;而EMA、CK(AE1/AE3)呈阴性.结论 上皮样血管平滑肌脂肪瘤是一种具有恶性潜能的间叶源性肿瘤,形态学上常容易误诊,免疫组化对鉴别诊断有重要意义.     

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。     

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。     

肾脏混合性上皮间质肿瘤

目的探讨肾脏混合性上皮间质肿瘤的临床病理特征。方法观察4例肾脏混合性上皮间质肿瘤的临床资料、镜下及免疫组织化学特点。结果患者3例女性,1例男性。临床表现主要为腰部不适和血尿,影像学检查示肾脏囊实性占位性病变。病理检查：肉眼肿瘤呈囊实性结构,镜下肿瘤由上皮和间质成分共同构成。上皮细胞可呈立方状、柱状、鞋钉样;其中1例上皮成分呈苗勒管上皮分化和肠上皮分化。间质成分为梭形细胞,并可见特征性呈束状分布的平滑肌组织和厚壁血管。免疫组织化学：上皮细胞AE1／AE3阳性,间质细胞雌激素受体（ER）、孕激素受体（PR）、平滑肌肌动蛋白（SMA）阳性。患者行肾切除术,术后随访未见复发。结论肾脏混合性上皮间质肿瘤为具有独特组织病理学特点的良性肿瘤,需要和肾脏其他良恶性肿瘤鉴别。     

血管周上皮样细胞肿瘤的分子遗传学

血管周上皮样细胞肿瘤(perivascular epithelioid cell tumours,PEComas)是由组织学和免疫组织化学上有独特表现的血管周上皮样细胞构成的间叶性肿瘤,PEComas家族包括肾血管平滑肌脂肪瘤、肺透明细胞"糖"瘤、淋巴管肌瘤病、淋巴管平滑肌瘤、镰状韧带透明细胞肌黑色素细胞性肿瘤和其他部...     

腹膜后恶性血管周上皮样细胞肿瘤的临床病理分析

目的:探讨腹膜后血管周上皮样细胞肿瘤(perivascular epithelioid cell neoplasms,PEComas)的临床和病理学特点,提高对PEComas的认识和诊断水平。方法:对1例腹膜后恶性PEComas进行临床病理分析及免疫组织化学研究,并复习相关文献。结果:肿瘤组织主要由上皮样细胞构成,胞质丰富、透明或嗜酸性颗粒状,间质富于血管。免疫组织化学显示:肿瘤细胞平滑肌肌动蛋白、HMB45,melan A及Desmin阳性,上皮膜抗原和vimentin局灶阳性,CgA,Syn,S-100,CD117,CD34,细胞角蛋白,calretinin及inhibin均阴性。结论:腹膜后PEComas是一种非常罕见的肿瘤,具有独特的组织学和免疫组织化学特征,应与腹膜后其他上皮样细胞肿瘤进行鉴别。     

14例肝血管平滑肌脂肪瘤病理形态分析

目的 观察肝血管平滑肌脂肪瘤（ＨＡＭＬ）的形态学特点。方法 采用ＨＥ切片、ＰＡＳ糖原和免疫组织化学ＳＰ法染色、电镜观察等对本院１０例及会诊４例ＨＡＭＬ进行研究。结果 １４例ＨＡＭＬ均显示肿瘤细胞围绕血管呈上皮样排列,血管分厚壁及薄壁２种,上皮样细胞分为４种形态,形态与免疫表型有一定相关关系,部分上皮样细胞胞质ＰＡＳ阳性且抗淀粉酶消化,电镜下可见类似前黑色素小体及密体。结论 肌动蛋白、ＨＭＢ４５阳性     

儿童肾脏上皮样血管平滑肌脂肪瘤病理特点

目的 探讨儿童肾脏上皮样血管平滑肌脂肪瘤(epithelioid angiomyolipoma,EAML)免疫标记的表达特点及其对临床病理诊断、鉴别诊断和预后的意义.方法 对1例肾脏EAML临床资料进行复习,进行光镜观察和免疫组化染色,并随访.结果 光镜下肿瘤由典型性的上皮样细胞组成,细胞核有异型性,核分裂象可见,有坏死和出血;淋巴结内未见上皮样肿瘤细胞累及.免疫标记:瘤细胞vimentin、SMA、HMB-45、Melan-A、CD68均阳性;而CK(AE1/AE3)、EMA、S-100、CD10、CD34、CD117、ER、PR、Ki-67和p53均为阴性.患者手术后状态良好,无肿瘤局部复发和转移征象.结论 肿瘤以上皮样细胞增生特征为主,临床表现和组织学表现易与肾脏肿瘤及其他肿瘤相混,寻找经典血管平滑肌脂肪瘤的结构和肿瘤细胞表达HMB-45和SMA对诊断和鉴别诊断至关重要.而细胞的不典型性、核分裂、出血和坏死可能只表明肿瘤的恶性潜能;淋巴结受累、肾静脉瘤栓均不是恶性的诊断依据;远处转移才是恶性的证据.Ki-67和p53对患者的预后可能有指示意义.     

上皮样血管平滑肌脂肪瘤的临床病理特征

目的:探讨上皮样血管平滑肌脂肪瘤(epithelioid angiomyolipoma,EAML)的临床病理学特征.方法:回顾性分析17例病理诊断为EAML的组织学形态、免疫组织化学特点、临床及随访资料.结果:男5例,女12例,年龄21~62(平均31.2)岁,其中14例发生于肾脏(3例伴有子宫平滑肌瘤,2例伴有宫内孕);2例发生于肝脏,1例发生于腹腔;肿瘤最大径3~15 cm,镜下瘤细胞呈上皮样巢、片状分布,可见围绕血管呈放射状排列的结构;细胞体积大,卵圆形、梭形,胞质丰富,异型明显,核分裂少见,其中2例伴有出血、坏死.免疫组织化学HMB-45,Melan-A,SMA阳性,vimentin,ER和PR表达率分别为41%(7/17),23%(4/17)以及35%(6/17).17例EAML均行肿瘤根治或肿瘤切除术,术后随访5~52个月,1例2年后肝肺转移死亡,其余16例均健在,无复发及转移.结论:EAML多发生于女性,可能与激素水平有关;肾脏最常见,其次为肝、腹腔;病理形态多样,免疫组织化学对其诊断有重要价值,手术效果好,有转移可能.     

Malignant epithelioid angiomyolipoma of the kidney in a patient with tuberous sclerosis: an autopsy case report with p53 gene mutation analysis

We report an autopsy case of malignant epithelioid angiomyolipoma in a 36-year-old male tuberous sclerosis patient. He had been diagnosed to have a bilateral renal tumor 20 years previously. The left kidney had been surgically resected at the age of 34, and the left renal tumor was pathologically diagnosed as classic angiomyolipoma and epithelioid angiomyolipoma. He suddenly died of cardiac arrest, and at autopsy the right kidney weighed 7120 g. The tumor presented with massive necrosis invading the inferior vena cava, but was not hemorrhagic. Microscopic examination revealed tumor cells varying in size with a predominantly solid proliferation pattern and marked atypical large cells with vesicular nuclei and abundant eosinophilic cytoplasm. Mitotic figures were often encountered, and atypical forms were also present. Metastatic lesions were identified in the right lung, liver, diaphragm, and mesentery. Immunohistochemical examination showed epithelioid angiomyolipoma cells that were focally reactive for HMB-45 and showed diffuse positive staining for Melan-A. No mutation was detected in the p53 gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis despite diffuse immunoreactivity for p53. This case was proven to be malignant because of the occurrence of distant metastases, and showed that p53 mutations are not always associated with malignant transformation in epithelioid angiomyolipoma.     

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.     

Malignant pigmented clear cell epithelioid tumor of the kidney: clear cell ("sugar") tumor versus malignant melanoma

A 73-year-old woman presented with an hemorrhagic kidney tumor initially interpreted as a renal cell carcinoma (RCC). A retroperitoneal recurrence infiltrating the duodenal wall was made up of clear cells, some of which contained Fontana-Masson positive pigment, immunopositive for HMB-45, S-100 protein, actin, and vimentin. The same immunohistochemical profile was retrospectively reproduced in the kidney tumor, where melanosomes were also found ultrastructurally. Lipomatous differentiation was not observed. There was no history of malignant melanoma (MM), or stigmata of tuberous sclerosis. The patient died of disease 5 years after the initial diagnosis. This neoplasm can be considered as a malignant, pigmented, clear-cell epithelioid variant of angiomyolipoma, or "sugar" tumor of the kidney, with the peculiarity of having a previously unreported component of pigmented cells visible on light microscopy. This finding raises the possibility that the exceptional cases of MM reported in renal parenchyma may be pigmented variants of epithelioid angiomyolipoma rather than true MM.     

Coexistence of renal epithelioid angiomyolipoma and clear cell carcinoma in patients without tuberous sclerosis

Renal epithelioid angiomyolipoma (EAML) is a rare but distinct variant of angiomyolipoma, closely simulating renal cell carcinoma or sarcoma both clinically and histopathologically. This report presents an unusual case of unilateral simultaneous renal EAML and renal clear cell carcinoma. A 52-year-old man without any sign of tuberous sclerosis had a complaint of 6-month history of pain in left renal area and had macroscopic hematuria twice within the recent 1 month. Computed tomography showed the presence of 2 masses in the upper and lower portion of the left kidney. The patient underwent left radical nephrectomy. Histological examination revealed the upper mass was composed of medium to large epithelioid cells with clear or eosinophilic cytoplasm and numerous giant multinucleated cells. Adult-appearing adipose tissue and coagulative necrosis could also be observed focally in the mass. Immunohistochemically, the tumor cells in the upper mass showed positive reactions to actin, HMB-45, Melan-A, and CD68 but negative reactions to pan-cytokeratin (pan-CK), epithelial membrane antigen, and CD10. However, the lower mass was composed of diffusely monomorphic clear cells with strongly immunoreactive for pan-CK, vimentin, and CD10, whereas without expression for HMB-45 and actin. The patient showed no evidence of recurrence or metastasis during 1-year postoperative following-up period. To the authors' knowledge, this is the first report of coincidental renal EAML and clear cell carcinoma in the same kidney. Unlike classic triphasic angiomyolipoma, adjuvant therapy after resection should be considered for renal EAML because of its malignant potential, more aggressive behavior and poor prognosis.     

Renal epithelioid angiomyolipoma: a case report and literature review

BACKGROUND: Renal epithelioid angiomyolipoma is a recently recognized variant of angiomyolipoma, closely simulating renal cell carcinoma both clinically and histologically. Only a relatively small number of cases of epithelioid angiomyolipoma of the kidney have been reported. AIM: To highlight clinicopathological features of this rare tumour. OBSERVATION: We report herein a new case of renal epithelioid angiomyolipoma in a 38-year-old male with no stigmata of tuberous sclerosis. The tumour was composed of diffuse sheets of epithelioid cells, small numbers of adipocytes and occasional blood vessels. Immunohistochemically, neoplastic cells were immunoreactive for HMB-45, but negative for cytokeratin. The patient showed no evidence of recurrence or metastatic disease one year after radical nephrectomy. CONCLUSIONS: Epithelioid angiomyolipoma may be locally aggressive and can metastasise; therefore, long-term post-operative follow-up is mandatory.     

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.     

Renal epithelioid angiomyolipoma--a close mimic of renal cell carcinoma. Report of a case and review of the literature

The epithelioid variant of angiomyolipoma (EAML) is a rare tumor of unpredictable behavior that is composed of epithelioid, spindle, and giant cells and contains no or only a minimal amount of lipomatous tissue. The picture can lead to an erroneous diagnosis of renal cell carcinoma or sarcoma. We report on a case of EAML in the kidney of a 47-year-old female without any signs of tuberous sclerosis and review the literature. Grossly, a well-demarcated, spheroid, largely hemorrhagic tumor measuring 4.2 cm in diameter occupied the central third of the kidney. Histologically, it was solid, highly cellular, with occasional microcysts, composed of medium to large epithelioid cells with clear or oxyphilic cytoplasm, short spindle cells, and numerous giant multinucleated cells. After extensive sampling, adult-appearing fat tissue was found to present as rare foci of microscopic dimensions. Immunohistochemically, the tumor cells showed positive reactions with antibodies against HMB-45, melan A, CD-68, muscle-specific actin, and, rarely, smooth muscle actin. Cytokeratins and epithelial membrane antigen were negative. The EAML is a variant growing in a carcinoma-like pattern that can lead to an erroneous diagnosis of renal cell carcinoma. An extensive sampling and HMB-45 and CD-68 positivity combined with cytokeratin negativity are of paramount importance for the correct diagnosis. As a sporadic renal tumor it followed a benign course in most of the reported cases.     

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.     

Triple synchronous neoplasms in one kidney: report of a case and review of the literature

We report the case of a patient with three synchronous but histologically different primary renal tumors that were all in the same kidney. Two tumors were different subtypes of renal cell carcinoma (RCC), and the third was a variant form of angiomyolipoma. The patient was a 62-year-old man who was receiving antihypertensive drugs and came to our hospital for a regular check-up. Ultrasonography performed during the visit revealed a left renal mass, but the patient had no related symptoms. Subsequent computed tomography revealed two round, high-density masses, one in the mid-portion and the other in the lower pole of the left kidney, and multiple cysts in the right kidney and the liver. The mass in the mid-portion measured 3.3 x 3.0 x 2.8 cm, and the mass in the lower pole measured 1.7 x 1.1 x 0.9 cm. A left radical nephrectomy was performed. On gross examination, an additional ovoid nodule (0.6 cm in the greatest dimension) was found in the lower pole. Microscopically, the largest tumor consisted of a broad alveolar arrangement of large round cells with abundant eosinophilic or clear cytoplasm, distinct cell borders, and perinuclear halos, features consistent with chromophobe RCC. The smallest tumor was a conventional (clear-cell) RCC. The third tumor was composed solely of atypical epithelioid cells with prominent nucleoli and yellowish-brown to black pigments. The tumor cells were positive for melanin (Fontana-Masson stain), the melanoma marker HMB45, vimentin, smooth-muscle actin, and the macrophage marker CD68 and were negative for cytokeratin. This tumor was considered a pigmented epithelioid type of angiomyolipoma. The histologic, histochemical, and immunohistochemical features in this case confirmed the presence of three synchronous primary tumors, a chromophobe and a clear-cell type RCC and a pigmented epithelioid angiomyolipoma, all of which were in the same kidney. This case is the first of its type reported in the literature.