Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases

Diagnosis of renal angiomyolipoma (AML) by fine-needle aspiration (FNA) may be difficult because cytological and radiological findings sometimes overlap with renal cell carcinoma (RCC) and liposarcoma. Five FNAs of AMLs were studied. Epithelioid and spindle stromal cells were arranged in loosely cohesive clusters and singly. The chromatin was evenly distributed and bland. Occasionally nuclear atypia was identified. Nuclei were oval to elongated, nucleoli were inconspicuous or absent, naked nuclei were present in three specimens, and intranuclear inclusions were present in two specimens. The cytoplasm was delicate and sometimes finely vacuolated. Adipose tissue was observed in two specimens. Thick-walled vessels, mitoses, and necrosis were absent. Corresponding surgical material showed typical features of AML. In FNA, bland chromatin and inconspicuous nucleoli distinguish renal AML from RCC and liposarcoma. Adipose tissue is not universally present. Cellular atypia in conjunction with overlapping radiological findings with RCC and liposarcoma are potential diagnostic pitfalls. Immunocytochemical (ICC) stains may elucidate the correct diagnosis.     

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.     

Fine-needle aspiration biopsy of breast adenomyoepithelioma: A potential false positive pitfall and presence of intranuclear cytoplasmic inclusions

Cytologic diagnosis of adenomyoepithelioma can be very challenging. We report fine needle aspiration cytology (FNAC) findings of a benign adenomyoepithelioma. The cytologic features are characterized by hypercellularity and the presence of numerous atypical dispersed cells with epithelioid morphology and intact cytoplasm. The nuclei showed stippled chromatin, irregular nuclear membrane, and prominent eosinophilic nucleoli. No necrosis or mitoses were seen. The presence of naked nuclei, and extensive intranuclear cytoplasmic inclusions were identified and raised the possibility of adenomyoepithelioma. Immunohistochemically, the atypical cells showed strong positivity for myosin heavy chain, p63, and CK5/6, while the epithelial cells reacted with estrogen receptors. This immunophenotypic pattern supports the myoepithelial origin of the atypical cell proliferation and favors the diagnosis of benign adenomyoepithelioma. However, biopsy was recommended to exclude malignancy. Histologically, the tumor showed prominent myoepithelial cells with significant atypia, intranuclear cytoplasmic inclusions, and dense cytoplasm. No evidence of malignancy was identified. In conclusion, we report a case of adenomyoepithelioma with a significant cytological atypia that may result in confusion with malignant breast tumors. The presence of intranuclear cytoplasmic inclusions, naked nuclei, and expression of myoepithelial markers should provide clues to the right diagnosis and benign nature of this lesion. Cytopathologists should be familiarized with this entity to avoid a misdiagnosis of carcinoma. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.     

Renal epithelioid angiomyolipoma: Histopathologic review,immunohistochemical evaluation and prognostic significance

Epithelioid angiomyolipoma (EAML) is considered to be a potentially malignant tumor and requires a differential diagnosis from renal cell carcinoma. In this study, we assessed the clinicopathologic features of renal EAML and evaluated the prognostic significance. Among 78 angiomyolipoma (AML) patients, a total of 5 EAMLs were identified, accounting for 6.4% of the total AML cases. The mean age was 41.4 years, and the average tumor size was 12.7 cm in diameter. Association of tuberous sclerosis complex was identified in two cases. One EAML case showed malignant behavior with local recurrence and distant metastasis. The malignant EAML had a larger tumor size, a higher percentage of epithelioid component and atypical epithelioid cells, ≥2 mitoses per 10 high power fields with atypical mitosis, necrosis, extrarenal extension, and carcinoma‐like growth pattern. Furthermore, the malignant case revealed p53 immunoreactivity and decreased membranous E‐cadherin expression. Pathologic evaluation of adverse prognostic factors will be helpful for risk stratification and prognosis estimation of EAML patients.     

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.     

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.     

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.     

Renal epithelioid angiomyolipoma with malignant features: Histological evaluation and novel immunohistochemical findings

Renal epithelioid angiomyolipoma (EAML) is a potentially malignant tumor type whose characteristics and biomarkers predictive of malignant behavior have not been elucidated. Here, we report three cases of renal EAML with malignant features but without histories of tuberous sclerosis complex. Case 1 involved a 29‐year‐old man with a 12‐cm solid mass in the right kidney who underwent radical right nephrectomy. Case 2 involved a 22‐year‐old woman with a retroperitoneal mass who underwent radical right nephrectomy and retroperitoneal tumorectomy. Local recurrence was detected 7 years post‐surgery. Case 3 involved a 23‐year‐old man with a 14‐cm solid mass in the left kidney who underwent radical left nephrectomy. Microscopically, the tumors in all cases demonstrated proliferation of epithelioid cells with atypia, mitotic activity, necrosis, hemorrhage, and vascular invasion. Epithelioid cells in all cases were immunohistochemically positive for melanocytic and myoid markers and weakly positive for E‐cadherin and β‐catenin. Immunohistochemistry revealed activation of the mammalian target of rapamycin pathway. Here, we report the morphological and immunohistochemical features of clinically or histologically malignant renal EAML.     

Renal angiomyolipoma: Clinico-pathologic study of 17 cases with emphasis on the epithelioid histology and p53 gene abnormalities

BackgroundEpithelioid angiomyolipoma (EAML) is a rare potentially malignant variant of renal angiomyolipoma (RAML).This study aims to determine whether RAML clinico-pathologic and molecular features (i.e. p53 gene abnormalities) differ significantly with regards to its histologic variant or to the presence of an epithelioid component within it.MethodsConsecutively resected RAML were reviewed, tumours comprising at least 80% of epithelioid cells were considered as EAML according to the 2016 World Health Organization classification of tumours of the kidney. P53 gene abnormalities were investigated using both immunohistochemical and molecular analysis.ResultsA total of 3 EAML among 17 RAML were identified, accounting for 3.9% of the total AML cases. Fatty aspect on imaging was more observed within tumours devoid of an epithelioid component. EAML showed a higher mitotic rate and a stronger p53 staining, no renal poles involvement and was not treated by nephron sparing surgeries. RAML comprising an epithelioid component demonstrated severer nuclear atypia as well as stronger p53 staining. P53 gene sequencing revealed a missense mutation (c.747G > C) in one classic AML harbouring a strong labelling with p53.ConclusionsStrong p53 staining in a RAML, even in the absence of gene mutation, may suggest the presence of an epithelioid component or of a truly EAML. To the best of our knowledge, c.747G > C p53 gene mutation is being reported for the first time in a RAML, although its role in AML pathogenesis is still unknown.     

Fine-needle aspiration cytology of malignant peripheral nerve sheath tumors

The histopathologic features of malignant peripheral nerve sheath tumors (MPNSTs) have been well described. There have been limited studies on the cytologic features of MPNST. In this present study, we have retrospectively reviewed eight histopathology confirmed cases of MPNST over a 5-year period. Detailed cytomorphological analysis of these cases was carried out individually by two observers. On cytology, these cases were diagnosed as benign spindle-cell tumor (two), spindle-cell tumor possibly benign (one), spindle-cell tumor possibly malignant (one), malignant spindle-cell tumor (two), spindle-cell tumor, and neural origin (two). The cardinal cytomorphologic features were loosely cohesive clusters and fascicular arrangement of spindle cells with rounded ends. The kinking of nuclei was not a conspicuous finding. Fibrillary background was noted in two of the cases. Nuclear pleomorphism was ranged from mild to moderate degree. One case exhibited extensive intranuclear pseudoinclusions. Mitotic figures (including atypical forms) were present in almost all the cases. Possibly a constellation of cytologic features such as clusters of short and long fascicles of cells admixed with dissociated spindle cells of round-ended nuclei and prominent nucleoli on myxoid or fibrillary background and frequent mitosis may be helpful in diagnosis of MPNSTs. The cytomorphologic features along with clinical correlation are necessary to increase the diagnostic accuracy of MPNST on aspiration cytology.     

Renal-cell carcinoma with intranuclear inclusions metastatic to thyroid: a diagnostic problem in aspiration cytology

A case of renal-cell carcinoma (RCC) exhibiting prominent intranuclear inclusions in a metastasis to the thyroid is presented. RCC had been treated in this patient by right nephrectomy 7 yr earlier and by left partial nephrectomy 5 yr earlier; the patient had also received radiation to the neck 4 yr earlier for carcinoma in situ of the left true vocal cord. Aspiration performed on a rapidly enlarging mass in the left lobe of the thyroid revealed both clusters of tumor cells and single tumor cells with prominent intranuclear inclusions. Definitive distinction between a primary and metastatic neoplasm was difficult on the aspiration specimen. Subsequent thyroidectomy confirmed the diagnosis of metastatic renal-cell carcinoma with intranuclear inclusions by histologic, immunohistochemical, and ultrastructural analysis. The differential diagnosis by aspiration cytology of thyroid neoplasms that contain intranuclear inclusions is discussed.     

Proximal‐type epithelioid sarcoma of the maxilla with metastasis to the scalp: Cytologic findings of an unusual malignant tumor

Epithelioid sarcoma of proximal type (ESPT), a subtype of epithelioid sarcoma, is an uncommon malignant neoplasm of the soft tissue with histo‐ and cytologic features similar to epithelioid sarcoma, classic type and to the more commonly encountered extra‐renal malignant rhabdoid tumor (EMRT). Unlike classic epithelioid sarcoma, ESPT usually involves pelvic, perineal, and genital regions and has an aggressive clinical course. Like EMRT, ESPT can have aberrations of the INI1 gene on chromosome 22q, which results in the loss of INI1 protein expression. We describe here the cytological findings of an ESPT metastatic to the scalp in a 14‐year‐old boy. Cytological preparations showed a discohesive population of pleomorphic ovoid to polygonal cells with large irregular nuclei and prominent nucleoli. Isolated cells with rhabdoid features were noted. These cells had abundant cytoplasm and occasional intracytoplasmic hyaline inclusions. In the light of the patient's clinical history of a known primary ESPT of the maxilla, the cytologic features were distinct enough to render a diagnosis of a metastatic lesion to the skull. Diagn. Cytopathol. 2010;38:744–747. © 2010 Wiley‐Liss, Inc.     

Atypical pleomorphic epithelioid angiomyolipoma localized to the pelvis: a case report and review of the literature

AIMS: Angiomyolipoma is the most common mesenchymal tumour of the kidney. It has been reported in several other sites outside the kidney, mainly in the liver. We report the first case of atypical pleomorphic angiomyolipoma in a man, arising from the pouch of Douglas and extending to the entire abdominal cavity. METHODS: A 17-year-old man underwent a complete resection of a giant abdominopelvic mass. The tissue was formalin fixed and paraffin embedded and 4 micro m thick histological sections were stained with haematoxylin-eosin. Immunohistochemical stains for HMB-45, smooth muscle actin, vimentin, calponin, S100 and desmin were performed. Sections for electron microscopy were also prepared. RESULTS: Microscopic examination revealed a neoplasm composed of pleomorphic epithelioid cells with atypical features, immunoreactive for HMB-45, MART-1, actin, vimentin and calponin, while S100 protein and desmin stains were negative. Ultrastructurally, the tumour cells showed prominent nucleoli, vacuolated cytoplasm, and some premelanosomes. A diagnosis of atypical pleomorphic epithelioid angiomyolipoma was then made. CONCLUSIONS: To date five patients with abdominal epithelioid angiomyolipoma have been described in the literature. All were women. Three of the five patients reported developed metastasis, while our patient is still free of disease at 16 months of follow-up. Clear prognostic pathological features have not been identified.     

肾脏上皮样型血管平滑肌脂肪瘤临床病理分析

目的 探讨肾脏上皮样型血管平滑肌脂肪瘤(EAML)的临床病理特点及诊断与鉴别诊断.方法 通过对3例EAML临床病理学观察与免疫组化标记及复习有关文献,讨论其组织学特征及临床生物学行为.结果 3例年龄分别为28、40和32岁,均有腰痛病史,其中1例伴有肉眼血尿,均无结节硬化症.眼观:肿瘤位于肾脏,直径大小分别为6 cm、8 cm和3 cm.3例境界清楚,例2伴囊性变.肿瘤无包膜,2例出血、坏死明显,质脆或韧.镜检:瘤细胞体积大或巨大,呈多边形,胞质丰富,嗜酸性或空泡状,核仁明显,可见核内包涵体,多核巨细胞散在其中.瘤细胞弥漫性或巢团状排列.2例瘤组织出血、坏死明显,呈浸润性边缘.3例未见典型AML图像.免疫组化染色显示瘤细胞HMB-45阳性,SMA和vimentin散在性阳性,CK、EMA和CD10均阴性.结论 EAML是一种单一方向分化的,含有大上皮样细胞的肿瘤,瘤细胞较为特异的表达HMB-45.辅以免疫组化可以与其它肾脏肿瘤相鉴别.     

卵巢浆液性肿瘤的电镜诊断

对20例卵巢浆液性肿瘤进行了电镜观察,并与光镜观察对比。提出分支管道样腔、纤毛及顶浆分泌是浆液性肿瘤电镜诊断的主要指标。而核不规则形伴细桥和分叶核形成、核内胞浆包涵体及畸形核仁是确认细胞指征。纤毛杆的大量出现是肿瘤细胞分化成熟的表现,但纤毛杆缺如不一定是不成熟的征象。核糖体丰富及粗面內质网减少是癌细胞分化低下的表现?疚奶致哿私盒韵傧宋龅拿?认为改成浆液性纤维腺瘤更符合肿瘤命名原则。     

A case of pulmonary malignant epithelioid hemangioendothelioma misdiagnosed as adenocarcinoma by fine needle aspiration cytology

Malignant epithelioid hemangioendothelioma (MEHE) is a rare vascular tumor with a biological behavior that lies between those of classical epithelioid hemangioendothelioma and angiosarcoma. Furthermore, MEHE is rarely diagnosed by fine needle aspiration cytology. The authors describe the cytological features of MEHE in a 41-year-old man who presented with increasing dyspnea over a period of 1 month before admission. Computed tomography of the chest showed a 3 cm poorly defined mass in the right lower lobe. Fine needle aspiration cytology demonstrated cellular smears of loosely cohesive clusters of epithelioid cells with numerous intracytoplasmic lumens in a necrotic background. Cellular features included fine chromatin and vesicular or slightly hyperchromatic nuclei with inconspicuous nucleoli and intranuclear inclusions. Nuclear membranes were relatively irregular with indentation. Mean N/C ratio was not increased, presumably due to a moderate amount of cytoplasm. The histologic examination displayed epithelioid and spindle cell proliferation with necrosis accompanying a classical epithelioid hemangioendotheliomatous area. The immunohistochemical evaluation was confirmatory and showed immunoreactivity for vascular markers. The authors also reviewed FNAB findings of epithelioid angiosarcoma, primary adenocarcinoma, and bronchioloalveolar carcinoma of the lung to identify cytomorphologic differences by literature bases. MEHE of the lung is difficult to diagnose cytologically because of its rarity and its cytomorphologic similarities with other malignant epithelial and mesenchymal tumors. However, it may be possible to distinguish it from other entities when the possibility of this unusual vascular neoplasm is suspected and ancillary studies are supportive.     

Bizarre stromal cells in ischemic bowel disease

The presence of bizarre stromal cells has been reported in gastrointestinal and extraintestinal lesions. We describe, for the first time, the presence of bizarre stromal cells with a cytomegalovirus (CMV)-like appearance or ganglion-like cells in 3 cases of ischemic colitis. The 3 patients were males ranging in age from 62 to 78 years, showed varying degrees of cardiovascular insufficiency, and were diagnosed with ischemic colitis. Colonic biopsies showed changes of ischemic colitis of variable severity. Common to all 3 cases, within the granulation tissue, stromal cells showed a broad spectrum of morphologic alterations, ranging from just nuclear enlargement to striking atypical features, large pleomorphic, hyperchromic nuclei, and eccentric prominent nucleoli. Occasionally, these cells displayed an eosinophilic oval nuclear inclusion, surrounded by a clear halo, resembling CMV inclusions. In conclusion, the etiopathogenesis of these cells can be partially explained by hypoxia, inflammation, regeneration/repair, and cell turnover alone or, more probably, in combination in the granulation tissue response to injury. The morphologic spectrum of bizarre stromal cells and ganglion-like cells suggests an obvious differential diagnosis, which includes carcinoma and sarcoma. The finding of enlarged cells with eccentric intranuclear eosinophilic inclusions requires the exclusion of CMV. However, immunohistochemistry, together with an awareness of those atypical stromal cells, can occur in the setting of ulceration and/or polypoid lesions, preventing an incorrect diagnosis.