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.     

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.     

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.     

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.     

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.     

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.     

Ocular metastasis as first presentation of renal cell carcinoma: report of 2 cases

Authors report the cases of 2 patients who had an ocular lesion as the first sign leading to diagnosis of renal cell carcinoma, an uncommon presentation of this neoplasm. The first patient was a 59-year-old man presented with a mass in the right eye. The histological and immunohistochemical profile of the biopsy showed a probable renal cell carcinoma. A CT scan showed a solid mass in the left kidney. The patient underwent radical nephrectomy and excision of the ocular lesion and had an uneventful evolution. The second patient was a 72-year-old man presenting with an ulcerated lesion on the right inferior tarsal conjunctiva. An excisional biopsy of the lesion showed histological and immunohistochemical patterns of a clear cell carcinoma. Abdominal tomography disclosed a right peripheral renal tumor. A right radical nephrectomy was performed. Renal cell carcinoma may present atypically with metastases to quite uncommon organs. Nephrectomy may be of value in selected cases; the ocular metastases are usually excised for aesthetic and functional reasons.     

Monotypic epithelioid angiomyolipoma of the adrenal gland: an unusual site for a rare extrarenal tumor

Epithelioid angiomyolipoma (AML) is an uncommon renal mesenchymal tumor with malignant potential and is frequently associated with tuberous sclerosis. Extrarenal AMLs are rare, and to the best of our knowledge, this is the first reported case of a primary monotypic epithelioid AML of adrenal gland in a patient without evidence of tuberous sclerosis. The patient is a 42-year old man who presented with retroperitoneal hemorrhage resulting from spontaneous rupture of adrenal mass. Histologically, the tumor showed a prominent component of epithelioid smooth muscle cells with slightly pleomorphic nuclei, sometimes with prominent nucleoli and eosinophilic cytoplasm resembling oncocytic tumors. Epithelioid cells were positive for melanoma (HMB45 and positive MelanA) and smooth muscle markers (α-smooth muscle–specific actin), but not for epithelial markers (cytokeratin, EMA). Differential diagnosis from renal cell carcinoma, adrenal gland carcinoma, and metastatic carcinoma is often challenging because of its epithelioid morphology. Because primary and secondary malignant tumors are much more common and aggressive neoplasms, establishing the correct diagnosis has important therapeutic and prognostic implications.     

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.     

Primary malignant fibrous histiocytoma of the kidney

Primary renal malignant fibrous histiocytoma is a rare tumor of the kidney. It is clinically and radiologically indistinguishable from a renal cell carcinoma. Even following radical surgery, the tumor shows a strong predilection for local recurrence and the prognosis is generally poor. We report on a 32-year-old man with malignant fibrous histiocytoma of the kidney who remained free of recurrence for 1 year after radical nephrectomy.     

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.     

Malignant perivascular epithelioid cell tumor of the kidney with rare pulmonary and ileum metastases

Aims: To report one case of malignant perivascular epithelioid cell tumor (PEComa) of the kidney with rare pulmonary and ileum metastases and analyze its clinicopathological features. Methods: We analyzed the clinicopathological features of one case of malignant PEComa of the kidney with pulmonary and ileum metastases. Immunohistochemistry staining was performed. Results: The patient was a 48-year-old man with a renal mass approximately 14 cm × 11 cm × 8 cm in size. Microscopically, the tumor was mainly composed of polygonal epithelioid cells with dense eosinophilic cytoplasm and round nuclei with small nucleoli. Focal tumor cells showed pleomorphism with multinucleated giant cells and prominent nucleoli. The tumor cells nests were surrounded by thick-walled irregular blood vessels. Focal fat cells were found within the tumor. Hemorrhage and coagulative necrosis were also present. The tumor cells were positive for vimentin, HMB45, and Melan-A, and focally positive for SMA and S-100 protein. After 5 years and 5.6 years of nephrectomy, the tumor metastasized to the right lung and ileum, respectively. Conclusion: We first reported one case of malignant PEComa of the kidney with pulmonary and ileum metastases. Metastatic PEComa of the lung and ileum should differentiate from primary carcinoma, metastatic carcinoma, malignant melanoma, and gastrointestinal stromal tumor.     

Chromophobe renal cell carcinoma with neuroendocrine differentiation

Chromophobe renal cell carcinoma was described by Thoenes et al. in 1986, and associations with carcinoma of collecting ducts, conventional renal cell carcinoma and sarcomatoid renal cell carcinoma have been described. We report a case of chromophobe renal cell carcinoma which showed neuroendocrine differentiation. This is the first known case to be clearly identified as such. The patient was a 56‐year‐old man with constant right flank pain and hematuria; CT scan revealed an 8.5 cm non‐homogeneous mass involving the right kidney. Right radical nephrectomy was performed. The tumor showed a mixture of classical and eosinophilic patterns of chromophobe cell carcinoma. Additionally, it showed insular, glandular and rosetoid‐like formations embedded in a dense eosinophilic hyaline stroma. The cells were cuboid or cylindrical with well‐defined boundaries, finely stippled chromatin and a small nucleolus. The appearance of the cytoplasm varied from faintly eosinophilic to coarsely granular eosinophilic. Immunohistochemically, the neuroendocrine areas were reactive for C‐kit, epithelial membrane antigen, cytokeratin, cytokeratin 7, chromogranin A, neuron‐specific enolase, CD56 and S‐100 protein. Our case represents a typical chromophobe carcinoma with neuroendocrine differentiation. Additionally, the immunohistochemical profile in both types of lesion suggests a common origin from renal tubular cells.     

Low-grade mucosa-associated lymphoid tissue lymphoma involving the kidney: report of 3 cases and review of the literature

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue involving the kidney is rare. We report a series of 3 cases. The first case occurred in an 83-year-old woman who presented with back pain. The second case was a 53-year-old man with a history of sarcoidosis who was found, in the course of evaluation of sarcoidosis, to have a right renal mass. The third case occurred in a 72-year-old man who had a history of periorbital mucosa-associated lymphoid tissue lymphoma and had been treated with surgery and radiation 1 year prior to this presentation. Histologically, all 3 patients showed infiltrate of uniform small-to-medium-sized lymphocytes with irregular nuclear contours and abundant cytoplasm resembling centrocytes or monocytoid lymphoid cells. The first patient received chemotherapy without complications. The second patient underwent a partial nephrectomy and was asymptomatic at the subsequent follow-up. The third patient developed a pulmonary embolism following nephrectomy, and further follow-up is not available.     

Primary adrenal gland epithelioid sarcoma: A case report and literature review

Epithelioid sarcoma is a malignant mesenchymal neoplasm with morphologic and immunophenotypic epithelioid differentiation, which rarely arises in solid organs. We report a case of primary epithelioid sarcoma in the adrenal gland of a 31‐year‐old female. The patient initially presented with nausea and rectal bleeding, and subsequent imaging studies revealed a 4.4 cm left adrenal gland mass and left retroperitoneal lymphadenopathy. Clinical and radiological studies did not reveal tumor elsewhere in the patient. Histologic features were those of epithelioid sarcoma, proximal type with cohesive clusters of epithelioid tumor cells harboring frequent mitoses, and areas of necrosis. Immunohistochemical stains showed strong, diffuse expression of epithelial markers (pancytokeratin), and CD34 and Fli‐1. Partial and focal positive staining of CK7 was also noted. Nuclear expression of SMARCB1 (INI‐1) protein was lost. ERG was negative in this case. We believe that this is the second‐case report of a primary adrenal gland epithelioid sarcoma. Fli‐1 positivity was seen in our case, and ERG was negative as shown in some recent publications regarding epithelioid sarcomas.     

Intranodal palisaded myofibroblastoma originating from retroperitoneum: an unusual origin

Background

Intranodal palisaded myofibroblastoma is one of the primary mesenchymal tumours. The inguinal region is the commonest site of this rare tumour. As there are only about 55 such cases reported in the literature, the precise aetiology and pathogenesis have yet to be explained adequately. Here we report a case of a 72 year old man presented with incidental finding of intranodal palisaded myofibroblastoma in the retroperitoneal region.

Case Presentation

A 72-year old man presented with abdominal pain in right upper quadrant with an incidental finding of abdominal mass in the right flank. The computerised tomogram scan of abdomen confirmed acute cholecystitis with a 5 x 5 cm retroperitoneal mass. He underwent cholecystectomy with excision of this mass. He recovered well following his operation and was discharged from the hospital. Histological examination confirmed the diagnosis of intranodal palisaded myofibroblastoma.

Conclusion

To our knowledge, this is the first case of intranodal palisaded myofibroblastoma originating from retroperitoneum. Along with the rarity of this case, we also discussed its typical histopathological findings, aetiology and pathogenesis.     

Cytology diagnosis of metastatic clear cell renal cell carcinoma,synchronous to pancreas,and metachronous to thyroid and contralateral adrenal: Report of a case and literature review

Renal cell carcinoma metastases to pancreas, thyroid, and contralateral adrenal gland are decidedly uncommon. Clear cell renal cell carcinoma (CCRCC) is the most frequent subtype. Cytology diagnosis may be challenging. A 74‐year‐old male with remote history of vocal cord malignancy and hypertension presented with abdominal pain. Computed tomography (CT) revealed 8.4 cm left renal mass highly suspicious for renal cell carcinoma, a 1.8 cm mass within vessels near left adrenal and a 2.5 cm mass in pancreatic tail. Right pulmonary middle lobe showed two small nodules. Metastatic CCRCC was diagnosed on preoperative transgastric, endoscopic ultrasound guided fine‐needle aspiration cytology of pancreatic tail mass. Left radical nephrectomy and distal pancreatectomy and splenectomy confirmed CCRCC (pT3bNxM1), with metastases in adrenal and pancreatic tail. The 3p deletion identification in pancreatic tumor suggested CCRCC origin. Follow‐up positron emission tomography‐CT (PET‐CT) scan revealed left thyroid lower pole mass. Thyroid ultrasound showed three clustered 6 mm nodules in left mid pole. Ultrasound‐guided fine needle aspiration (US‐FNA) biopsies, 4‐month post‐nephrectomy, were consistent with metastatic renal cell carcinoma in lower, and atypia of undetermined significance in mid poles respectively. Left lobectomy and isthmus and pyramidal lobe resections confirmed metastatic renal cell carcinoma. One year post‐radical nephrectomy, contralateral adrenal lesion noted on PET‐CT was interpreted as metastatic CCRCC on CT‐guided core biopsy with touch imprints. Rapid on‐site evaluation was implemented, and immunoprofile typical of CCRCC substantiated cytomorphology at all three sites. Previously reported cases of renal cell carcinoma metastases to organs as in the described case are reviewed as well. Diagn. Cytopathol. 2017;45:161–167. © 2016 Wiley Periodicals, Inc.     

The recurrence of malignant pleural mesothelioma 14 years after extrapleural pneumonectomy: Possible histological transformation

A 56‐year‐old man underwent extrapleural pneumonectomy for malignant pleural mesothelioma (MPM). The histological diagnosis was epithelioid mesothelioma with T2N0M0, and no sarcomatoid component was observed. Subsequently, 14 years after complete resection, screening computed tomography detected a rapidly growing right thoracic mass, which was diagnosed as a recurrence of MPM on resection. However, it was composed of both epithelioid (50%) and sarcomatoid (50%) components, suggesting possible histological transformation. Although there have been some previous reports on the recurrence of MPM, to the best of our knowledge, this is the first clinical case which indicated that histological transformation of MPM might occur.     

Renal oncocytoma

Up to date only five cases of renal oncocytomas have been reported in Japan. We describe two cases of renal oncocytomas. Case 1: A 63-year-old woman, who had no urological symptoms, was pointed out of a cystic mass in the left kidney by chance. A resected kidney had a cystic tumor, which was well encapsulated and measured 6 X 7 X 8 cm. The tumor was unilocular and thick-walled cyst filled with bloody fluid. Histologically, the tumor was composed of oncocytes with eosinophilic granular cytoplasms that were packed with mitochondria. Case 2: A 70-year-old women died of malignant lymphoma and an autopsy was performed. The tumor was found in the right kidney by chance and measured 1 cm in diameter. The cut-surface of the tumor was uniform and tan-brown in color. Histologically, the tumor was composed of cells same as Case 1. We discuss the incidence of this tumor and the morphological characteristics of our cases.