Metanephric adenoma in a 59-year-old female: a case report

We report a case of metanephric adenoma in a 59-year-old female. The tumor was incidentally detected on computed tomography (CT) and ultrasound (US), and diagnosed as left renal cell carcinoma by radiological examination. Left nephrectomy was performed. The tumor measuring 4 x 3 x 3 cm had a clear margin and was encapslated with thick fibrous tissue. The cut surface was yellow-white and the boundary of renal parenchyma was clear. Histopathologically, the tumor showed a characteristic composition of small uniform cells with regular nuclei that formed a tubular pattern. Immunohistologically, they were positive for Leu-7 and vimentin. Pathological diagnosis was metanephric adenoma. We discuss the radiological findings of metanephric adenoma.     

后肾腺瘤临床及病理特点分析（附1例报告并文献复习）

目的：探讨后肾腺瘤的临床及病理特点。方法：报告1例后肾腺瘤患者的临床及病理资料．并复习相关文献予以讨论。结果：患者行根治性右肾切除术。镜下见肿瘤细胞大小一致．呈腺样及小管状排列．胞质少．细胞无明显异型性,核分裂像少见;免疫组织化学染色：WT1Vimentin、CK、EMA均阳性．Syn、RCC、SMA、HMB15、CD10、CD34、CgA、Chr均阴性;病理学诊断符合后肾腺瘤特点。术后随访18个月．未她肿瘤复发和远处转移。结论：后肾腺瘤是一种罕见的来源于肾脏上皮组织的肿瘤．了解该肿瘤临床及病理特点有助于临床诊断及鉴别诊断。     

Metanephric adenoma

A 59-year old woman was diagnosed with a tumour in her right kidney. A nephrectomy was performed, and a 45 mm diameter tan-pink coloured tumour was found. Microscopy revealed small, dark cells in organized arrays of small round acini and tubules with glomeruloid infoldings. A diagnosis of metanephric adenoma was made. The tumour cells proved diploid on flow cytometry and immunohistochemical staining was positive for CAM 5.2 and AE-3. FISH analysis of three chromosomes did not reveal any abnormal karyotype. It is important to differentiate metanephric adenoma from renal cell carcinoma and adult Wilm's tumour, since it has a benign course.     

Metastatic metanephric adenoma in a child

Metanephric adenoma is a recently characterized renal tumor that generally occurs in adults and has an excellent prognosis. To date, only one atypical metanephric adenoma has been reported to metastasize. The authors report a case of typical metanephric adenoma that arose in the left kidney of a 7-year-old girl that was associated with metastases to the para-aortic, hilar, and aortic bifurcation lymph nodes. The tumor was 9.5 cm and was composed entirely of epithelial elements arranged in tubules, short papillae, and glomeruloid bodies with scattered psammoma bodies. No atypia and only rare mitotic activity were present. Immunohistochemically, the tumor was negative for epithelial membrane antigen, negative for keratin AE1, and focally positive for both keratin CAM5.2 and cytokeratin 7. Tumor cytogenetics revealed a normal diploid karyotype, and disomy of chromosomes 7 and 17 was confirmed by fluorescence in situ hybridization. The authors conclude that tumors with histologic, immunohistochemical, and genetic features characteristic of typical metanephric adenoma can present with metastatic disease.     

A case of renal metanephric adenoma: Histologic, immunohistochemical and cytogenetic analyses

BACKGROUND: A unique case of metanephric adenoma of the left kidney is reported in a 61-year-old woman presenting with an incidental renal mass on ultrasonography. METHODS/RESULTS: On radiographic examination, the presence of hypovascular renal cell carcinoma was suspected and left radical nephrectomy was performed. The resected tumor, measuring 4.9 x 4.7 x 4.5 cm, was well-circumscribed and solid and its cut surface was tan-pink with foci of focal hemorrhage and cystic change. Microscopically, the tumor was composed of uniformly small acini with hyperchromatic round nuclei. Some acini were dilated and occasionally contained glomeruloid-like bodies and psamoma bodies. Immunohistochemically, tumor cells showed positive immunoreaction for vimentin, cytokeratin and Leu 7. Cytogenetically, the tumor did not show numerical aberrations of chromosome 7 or 17 by fluorescence in situ hybridization. CONCLUSIONS: The patient is alive without recurrence or metastasis 4 years after surgery. Metanephric adenoma must be differentiated from other renal tumors, particularly Wilms' tumor or low-grade renal cell carcinoma. Immunohistochemical and cytogenetic analysis may be helpful in difficult cases.     

Metanephric adenosarcoma in a young adult: morphologic, immunophenotypic, ultrastructural, and fluorescence in situ hybridization analyses: a case report and review of the literature.

Metanephric neoplasms are uncommon renal tumors that arise in both children and adults. They may be composed of small epithelial cells or benign stroma, or both, and are termed metanephric adenoma, metanephric stromal tumor, or metanephric adenofibroma, respectively. Thus far, these tumors have been known for their benign behavior. We present the case of a 21-year-old woman who developed a neoplasm composed of a renal epithelial component identical to metanephric adenoma combined with a malignant spindle cell sarcoma. The epithelial component was positive for pankeratin AE1/3, whereas the sarcomatous component was negative for epithelial markers and positive for vimentin, CD34, and CD117. No smooth muscle differentiation was apparent in the sarcoma by immunohistochemistry or ultrastructural analysis. By fluorescent in situ hybridization analysis of the sarcomatous component there was monosomy of the X chromosome, but no apparent variation from the normal diploid pattern for chromosomes 3, 7, 12, and 17. We conclude that the spectrum of metanephric neoplasia should be expanded to include malignant stromal variants, and we propose the term "metanephric adenosarcoma" for the present case.     

Simultaneous diagnosis of a metanephric adenoma and a clear cell carcinoma of the contralateral kidney

Metanephric adenoma of the kidney is a rare, newly recognized entity of a unique benign renal tumor. Clinically, pain, hematuria and palpable mass are the most common presenting signs. Females predominate by well over 2:1. A higher incidence of polycythemia is often found in these patients. Only a few cases of this type of adenoma have been reported in the literature. We report on a 78-year-old female patient with a metanephric adenoma of the left kidney, which showed typical clinical, radiologic, microscopic and immunohistochemical findings. A clear cell carcinoma of the contralateral kidney was also discovered and treated.     

肾脏后肾腺瘤1例报告并文献复习

目的：探讨后肾腺瘤的临床病理学特征,提高对后肾腺瘤的认识.方法：分析1例29岁女性后肾腺瘤患者的临床病理资料,并结合相关文献进行讨论.结果：患者因腰部不适行B超检查发现右肾肿瘤,16层螺旋CT诊断为右肾肿瘤（良性可能大）,行肾肿瘤剜除术,术中见肿瘤被膜完整,切面色灰白,质地均匀,术中冷冻切片诊断为乳头状肾细胞癌,随即行肾癌根治术.镜下肿瘤细胞呈腺样或乳头状排列,并有砂粒体.免疫组化：NSE（＋）、Ki67、Vim为阳性.病理诊断：右肾后肾腺瘤.随访22个月,未见肿瘤复发.结论：后肾腺瘤术前难以依据影像学特征明确诊断,术前肿瘤穿刺活检结合免疫组化对明确诊断可能是一种可行的选择,更重要的是,了解其临床及病理特点有助于该肿瘤的准确诊断.后肾腺瘤的治疗多采取保留肾单位的手术,但由于其生物学行为及细胞起源的不确定性,术后长期随访观察是必需的.     

Cardiac metastasis from a transitional cell carcinoma diagnosed by two-dimensional echocardiography

We report a rare case of symptomatic cardiac metastasis from a transitional cell carcinoma of the renal pelvis. A 57-year-old man presented with severe anemia, inflammation, hypoxemia and disseminated intravascular coagulation. Computed tomography revealed a large tumor in the left renal pelvis with multiple lymph node metastases. Two-dimensional echocardiography revealed large tumors in the right ventricle. The patient suddenly died because of the obstructive mass of the right ventricular outflow tract. Histopathological examination showed high-grade transitional cell carcinoma in the left renal pelvis and the right ventricle. There are only three cases of cardiac metastases from a transitional cell carcinoma reported in the literature.     

Metanephric adenoma of the kidney

BACKGROUND: Metanephric adenoma is a rare renal neoplasm that is histologically and clinically unique. We found this neoplasm in a 62-year-old female, whose renal tumor was incidentally detected on abdominal ultrasound examination. METHODS/RESULTS: Ultrasound, computed tomography and magnetic resonance imaging were compatible with those of renal cell carcinoma. With a diagnosis of renal cell carcinoma, right partial nephrectomy was performed. This tumor showed histologic similarity to developing metanephric tubular epithelium. It was composed of uniformly small epithelial cells, which formed tubules. CONCLUSIONS: The patient has been well and healthy for 20 months after surgery. The unique features of metanephric adenoma should be clinically and pathologically recognized because of its invariably benign course.     

Typical renal metanephric adenoma. Conservative surgery

Metanephric Adenoma is uncommon renal tumor included in the complex group of the embryologics or nefroblastics renal tumors. Generally occurs in young females and usually has excellent prognosis. It's important to differentiate of malignant variants, particularly renal cell papillary carcinoma, metanephric adenosarcoma and adult Wilms tumor. The suspicion and intraoperative analysis of the tumor can to facilitate the use of conservative renal surgery in order to avoid unnecessary radical and aggressive surgery. To exist cases of metastatic metanephric adenoma, and the totally benign characteristic of the metanephric adenoma and the malignant potential isn't totally clarify.     

Successful treatment of a case of advanced adult Wilms' tumor with pre-surgical chemotherapy, irradiation and radical nephrectomy

A 37-year-old male was referred with a huge renal mass and multiple lung lesions. Abdominal and chest computed tomographic scan revealed a 11×15×17. 5 cm right renal tumor and multiple lung metastases. Neither tumor was enhanced, and no lymph adenopathy was detected. Percutaneous needle core biopsy was performed and the tumors were diagnosed as Wilms' tumor histologically supported by immunohistological positive staining to WT-1 and CD56. Since lung metastases were detected and the renal tumor reached the abdominal aorta on the left side, presurgical systemic chemotherapy (ifosphamide＋ carboplatin＋etoposide ; ICEx 4 courses) was performed. The renal tumor and the lung metastases were markedly decreased in size and subjected to a radical nephrectomy. Histological examination confirmed the diagnosis of Wilms' tumor without anaplastic change categorized as mesenchymal type. As an adjuvant therapy, irradiation to renal bed (40 Gy/20 fr) and bilateral lung (12 Gy/8 fr) were performed. Six months after the end of the therapy, no evidence of recurrence was detected.     

后肾腺瘤临床、病理及影像学特征分析

目的 分析后肾腺瘤的临床、病理及影像学特征,并探讨其诊断及鉴别诊断.方法 收集2例经病理诊断为后肾腺瘤的病例,复习国内外相关文献报道,结合临床、影像学、病理组织学及免疫组织化学特征对后肾腺瘤进行分析总结.结果 影像学检查示乏血供性病变.形态学表现肿瘤细胞呈胚胎样,体积小且大小一致,含少量嗜酸性细胞质,染色质细腻,核仁不明显,无病理性核分裂象,瘤细胞呈小管状、腺泡状,局部可见乳头状增生,砂粒体可见;免疫组化：波形蛋白及细胞角蛋白呈不同程度阳性表达.结论 后肾腺瘤为一种少见的肾脏肿瘤,发生于单侧肾脏,临床及影像学特征不明显,最终诊断需病理确诊.     

肾脏孤立性纤维瘤临床、影像学及病理诊断(附2例报告及文献复习)

目的:探讨肾孤立性纤维瘤的临床、影像学及病理特征,并进行诊断和鉴别诊断,提高对该肿瘤的诊断水平。方法:对2例肾孤立性纤维瘤进行临床症状,影像学资料以及病理分析,并结合文献讨论。结果:2例肿瘤均位于左肾,1例来源于肾实质,1例与左肾盂关系密切,临床、影像学诊断为左肾癌,均行左肾根治性切除术,肿瘤大体为球形或表面略分叶状的包块,边界清楚,包膜完整。镜下梭形细胞呈束状、旋涡状或不规则状排列,部分与胶原纤维混杂,部分呈血管外皮瘤样结构。细胞无明显异型,核分裂象未见。免疫组化示肿瘤细胞CD34及CD99阳性,S100,SMA,CKpan,P63,HMB45均为阴性,确诊为肾脏孤立性纤维瘤,2例均随访6个月无复发转移。结论:肾孤立性纤维瘤是一种少见的肾脏肿瘤,临床及影像学上易误诊为肾癌或肾盂癌,免疫组化CD34阳性表达是其病理学特征性表现,根治性切除及术后长期随访是治疗肿瘤的必要手段。     

A case of renal cell carcinoma metastasizing to the contralateral kidney and renal pelvis

Extremely rarely renal cell carcinoma metastasizes to the contralateral renal pelvis or ureter. A 42-year-old man had undergone left radical nephrectomy for renal cell carcinoma (pT1b, grade 2) in March, 2000. Fifteen months later, he complained of macroscopic hematuria. Computed tomographic scanning and retrograde pyelography showed a right renal pelvic tumor. Enucleation of pelvic tumor was performed and a parenchyma mass incidentally identified in the right kidney was also resected. Histopathological examination of each tumor revealed renal cell carcinoma identical to the primary tumors in the left kidney suggesting metastasis to renal pelvis and de novo tumor or metastasis in the right kidney.     

Simultaneous bilateral renal pelvic tumors: a case report]

A case of simultaneous bilateral renal pelvic tumors is reported. A 64-year-old man with the chief complaint of gross hematuria and left flank pain was admitted. Clinical investigations revealed a tumor in the right pelvis and ureter, and another tumor in the left renal pelvis. The right ureteral tumor had invaded the bladder. Right nephroureterectomy, total cystectomy, left partial pyelectomy and ureterocutaneostomy were performed. By pathological examination, right renal pelvic and ureteral tumors were non-papillary transitional cell carcinoma, grade 3, pT4, and the left renal pelvic tumor was papillary transitional cell carcinoma, grade 2, pT1. To our knowledge, this is the 16th case of simultaneous bilateral urothelial tumors of the upper urinary tract in Japan.     

CA19-9-producing transitional cell carcinoma of the renal pelvis: a case report

We report a case of CA19-9-producing transitional cell carcinoma of the renal pelvis. A 59-year-old male patient with left hydronephrosis was referred to us from a local physician. Retrograde pyelogram revealed irregular filling defects involving calices, pelvis and proximal ureter. The serum CA19-9 level was elevated. Under the diagnosis of renal pelvic tumor, we performed radical left nephroureterectomy. The tumor was histologically diagnosed as transitional cell carcinoma. The tumor cells showed positive immunostaining for CA19-9. The serum CA19-9 level was normalized after the operation. To our knowledge, this is the 28th case of a CA19-9-producing tumor in the Japanese literature.     

Triple cancer in the urinary system: a case report

A 74-year-old male was referred to our hospital due to microhematuria that was pointed out at his health check-up. Cystoscopy showed many papillary bladder tumors under 5 mm in size. Intravenous pyelography also showed deformity of the right kidney and shadow defects in the left renal pelvis. Abdominal computed tomography revealed an 8 cm tumor invading the renal vein in the right kidney, and a 3 cm tumor in the left renal pelvis. Prostate biopsy was performed with PSA 3.4 ng/ml, and he was also diagnosed with prostate carcinoma. First, he received right radical nephrectomy, and secondly left nephroureterectomy and cystectomy. Our case should be called triple cancer because bladder cancer was thought to be daughter tumor of renal pelvic tumor. This is, to our knowledge, the 11th case report that occurred in the urinary tact, and the first case that needed total resection of urinary tract.     

L’adénome métanéphrique bilatéral du rein

Renal metanephric adenoma is an uncommon benign epithelial neoplasm. The diagnosis is exclusively histological. Differential diagnosis essentially includes Wilms’ tumor and papillary renal cell carcinoma. Cytogenetic analysis seems to be important for distinguishing these three histological entities. Bilateral metanephric adenoma of the kidney is an exceptional entity (to our knowledge only one case has been reported in the literature) which renders the differential diagnosis with bilateral cancer of the kidney difficult. We report a new case seen in a 64-year-old patient.     

A case of metanephric adenoma treated with partial nephrectomy

A 32-year-old female presented with a right renal mass detected by abdominal ultrasound examination at a routine medical check up. Computed tomography scans and magnetic resonance images revealed a solid tumor in the upper pole of the right kidney measuring 1.5 cm in diameter. Partial nephrectomy was performed on suspicion of the renal cell carcinoma. Histologically, the tumor is composed of small, uniform, epithelial cells with scant cytoplasm and hyperchromatic round nuclei that formed a tubular or glomerular-like structure. The histological diagnosis was metanephric adenoma.