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.     

Metanephric adenoma: report of two cases

We report 2 cases of metanephric adenoma a rare form of adenoma. One case occurred in a 54-year-old male preoperatively diagnosed with renal cell carcinoma who underwent left partial nephrectomy for a tumor 2 cm in size. Histology revealed a tumor with papillotubular structures consisting of small, uniform tumor cells. In immunohistochemical staining, tumor cells were positive for CD57 and WT-1. Thus, the patient was diagnosed with metanephric adenoma. The other case occurred in a 40-year-old male who underwent left nephroureterectomy for carcinoma of the renal pelvis. Carcinoma of the left renal pelvis was diagnosed as pT3N0M0. Incidental micronodules 2 mm in size and consisting of immature tubular structures were noted in the renal cortex. In immunohistochemical staining, tumor cells were positive for CD57 and WT-1, and the patient was diagnosed with metanephric adenoma. The aforementioned tumors frequently occur in middle-aged women and are often well-defined tumors that project from the renal surface outwards. On angiography, they have a hypovascular pattern and resemble papillary renal carcinoma. Preoperative differentiation of renal cell carcinoma and nephroblastoma is difficult. Mistaking such tumors for malignant tumors and subjecting patients to unnecessary adjuvant therapy must be avoided.     

Renal cell carcinoma presenting high serum level of CA19-9 due to hydronephrosis: a case report

A 58-year old female was referred to our hospital due to left renal cyst that was pointed out at her health check-up. Abdominal CT scan showed left hydronephrosis with a 20 x 12 x 11cm tumor. The serum CA19-9 level elevated to 4,400 U/ml. Urinary cytology in the left renal pelvis was negative, therefore we could not diagnose whether the mass was renal cell carcinoma or renal pelvic tumor before surgery. She underwent left radical nephrectomy, and frozen section revealed renal cell carcinoma. Immunohistological stain clarified CA19-9 was limited to epithelium lining the renal pelvis and was not contained in carcinoma cells. After the surgery, the serum CA19-9 decreased to the normal range. Serum CA19-9 is known to be sometimes elevated in patients with urothelial carcinoma, but rarely elevated in those with renal cell carcinoma. We thought that hydronephrosis by tumor occlusion caused CA19-9 elevation in our case.     

A case of metastatic renal cell carcinoma to the ovary

A 52-year-old woman had a pathological fracture of the right femur. On histopathological examination bone metastasis from renal cell carcinoma was suspected. Abdominal computed tomography showed a heterogeneous mass (9.1 x 7.8 x 6.5 cm) in the left kidney and a cystic multilocular mass (12 x 10 cm) in the pelvis. Bone scintigraphy revealed an abnormal uptake in the left coracoid process, right third rib, and right distal femur and proximal tibia. Clinical diagnosis was left renal cancer with multiple bone metastases (cT2NOM1, stage IV) and a right ovarian tumor. We performed left radical nephrectomy and resection of right ovarian tumor by bilateral adnexectomy. On histopathological examination, the left kidney tumor was diagnosed as renal cell carcinoma (clear cell carcinoma with chromophobe component, G2 > G1). The ovarian tumor consisted of carcinoma of clear cell type (G2) that resembled components of left renal cell carcinoma, confirming the diagnosis of metastatic renal clear cell carcinoma to the ovary. Although she underwent immunotherapy with interferon, she died 10 months after nephrectomy. Metastasis to the ovary from renal clear cell carcinoma is very rare and only 18 cases have been reported in the literature. This rarity may be related to the difficulty of differential diagnosis between metastatic renal cell carcinoma to the ovary and primary ovarian clear cell carcinoma. Elaborate analysis of microscopic features and immunohistochemical profiles may help in the distinction of this metastatic lesion.     

A case of malignant fibrous histiocytoma arising from the renal capsule

A 62-year-old man was admitted with a chief complaint of general malaise. Computed tomography showed a large mass adjacent to the parenchyma of the left kidney. The mass was 17 x 13 x 12 cm in size. Preoperative diagnosis was left renal cell carcinoma and left radical nephrectomy was performed. Histopathologically, the tumor was diagnosed as malignant fibrous histiocytoma (MFH), and the tumor was considered to have arisen from the renal capsule. There has been no recurrence for 7 months postoperatively. We review 40 cases of MFH arising from the kidney or the renal capsule in the literature.     

Collecting duct carcinoma with long survival treated by partial nephrectomy

A case is reported of collecting duct carcinoma of the left kidney treated with partial nephrectomy. A 57-year-old woman presented for evaluation of the left renal mass, which was detected by screening ultrasonography. A computed tomography scan and magnetic resonance imaging showed a solid mass at the upper pole of the left kidney. The renal tumor biopsy revealed a low-grade renal cell carcinoma or a tubulopapillary adenoma. Subsequently, left partial nephrectomy was performed. Microscopically, the tumor showed tubulopapillary proliferation with a fibrous capsule. Histochemically, the tumor cells reacted with lectins or antibodies against the collecting duct. Twenty-four months after partial nephrectomy, the patient is alive and has no distant metastatic lesions. We review the literature on collecting duct carcinoma, in addition to the case of partial nephrectomy.     

Renal adenoma treated with partial nephrectomy: a case report

We report a case of renal adenoma which was diagnosed as renal cell carcinoma preoperatively. A 78-year-old man, who had been under observation for bladder cancer for 4 years, was incidentally found to have a small right renal tumor at follow-up computed tomography (CT). Enhanced CT demonstrated a tumor which was hypervascular, 10 x 10 mm size, at the lower pole of the right kidney. There was no evidence of distant metastasis. The preoperative diagnosis was renal cell carcinoma, cT1aN0M0, and we performed right partial nephrectomy. The histopathorogical finding was renal adenoma. Renal adenomas are benign tumors and not uncommon in autopsy cases. However, when they are detected clinically, it is difficult to distinguish them from renal cell carcinoma preoperatively.     

Two cases of renal cell carcinoma accompanied with ossification]

We report two cases of renal cell carcinoma accompanied with ossification. Case 1: A 40-year-old male visited a physician with the complaint of epigastric pain. Examination of the stomach revealed compression of the greater curvature. Abdominal radiography and CT scan revealed a left renal mass with calcification, which was a hypovascular tumor on angiography. A transperitoneal left nephrectomy was performed. The resected kidney was 700g in weight and the tumor, which was 12 x 10 x 10 cm in size and located in the upper pole of the kidney, was enveloped with a hard capsule and was extensively necrotized. Histopathological diagnosis was renal cell carcinoma (papillary type, mixed subtype). Case 2: A 69-year-old female was occasionally pointed out to have a left renal mass in ultrasonic examination. It was accompanied with calcification in CT scan and a hypervascular tumor in angiography. A transperitoneal left nephrectomy was performed. The resected kidney was 320 g in weight and the tumor located in the lower pole of the kidney, was 6 x 6 x 6 cm in size and necrotized. Histopathological diagnosis was renal cell carcinoma (alveolar type, clear cell subtype). Microscopically in both cases, ossified tissue existed among the fibrous tissue in the necrotized lesion of the tumor, but not near the cancer cells and, it was accompanied by calcification. During the ossification process, the connective tissue proliferates after the necrosis of the tumor, and metaplasia occurred from its juvenile plastic cells to osteoblastic cells.     

Two case reports of unilateral adrenal hyperplasia with contralateral renal cell carcinoma

We report two cases of unilateral adrenal hyperplasia with contralateral renal cell carcinoma. First case was a 66-year-old man with right renal mass who came to our hospital for study. Although no major symptoms were complained, blood pressure was consistently above normal. Hypokalemia, low plasma renin activity and high plasma aldosterone level were detected. CT revealed that he had a right renal mass and a left adrenal tumor. Preoperative diagnosis was right renal tumor and primary aldosteronism due to left adrenal adenoma. Second case was a 59-year-old man with right renal mass who also came to our hospital for study. He also had a left adrenal tumor, however his blood pressure was normal and serum hormonal analysis showed normal adrenal cortical function. Preoperative diagnosis was right renal tumor and non-functional left adrenal adenoma. Two patients were performed right radical nephrectomy with contralateral adrenarectomy. Pathological diagnosis were right renal cell carcinoma and left adrenocortical hyperplasia. One Patient clinically showed primary aldosteronism and the other had no clinical symptoms. These patients were rare cases with unilateral adrenal hyperplasia.     

Hilar lymph node metastasis in renal cell carcinoma.

A 48-year-old man, who underwent a right nephrectomy for renal cell carcinoma 7 years earlier, was found to have hilar lymph node metastasis alone, without lesions, in the pulmonary parenchyma. Chest X-ray and CT findings showed a left hilar mass about 4 x 2.5 cm in diameter. Left bronchial arteriography showed a hypervascular mass lesion in the left hilum. Macroscopic tumor invasion of the pulmonary artery and left main bronchus indicated left pneumonectomy. The resected specimen was found histologically to involve metastatic renal cell carcinoma in the left hilar lymph node about 3 cm in diameter. Tumor metastasis was limited to the lymph node. The metastatic pathway of renal cell carcinoma to the hilar lymph node was considered lymphogenous via either retrograde lymphatic flow from the thoracic duct or through the lymphatics in the inferior pulmonary ligament.     

A case of metastatic tumor of spermatic cord from renal cell carcinoma

A 51-year-old man was admitted with the complaint of left scrotal swelling (11 x 5 x 5 cm). He had undergone left nephrectomy and removal of tumor thrombus in inferior vena cava due to renal cell carcinoma. Nine months after the nephrectomy, left scrotal enlargement was noticed. Left high orchiectomy was performed on January 20, 1988. A clear cell carcinoma was present in spermatic cord and pampiniform plexus histologically but testis and epididymis were intact. Renal cell carcinoma seemed to disseminate retrograde through the spermatic vein to spermatic cord. The metastatic tumor of spermatic cord from renal cell carcinoma is very rare and this case is the fifth case in the Japanese literature.     

Bilateral renal cell carcinoma in a patient receiving long-term dialysis

Bilateral renal cell carcinoma developing in a 55-year-old male receiving long-term dialysis is reported. The patient, who had undergone maintenance hemodialysis for 12 years, was admitted in July, 1986 for the purpose of extensive examination of a right renal mass. CT scan and ultrasonography demonstrated an enlarged bilateral kidney associated with multiple cysts, containing a solid mass in the right upper pole. The patients underwent right nephrectomy under the diagnosis of right renal tumor. The solid tumor 4 x 3 cm in size revealed a grade 1 to 2 renal cell carcinoma pathologically. Two small tumors were recognized in other portions of the kidney. Multiple cysts of varying sizes, the largest 2 cm in diameter, replaced the renal parenchyma. The cyst walls frequently contained hyperplastic changes. The patient has been subsequently followed up for 2 years and 9 months and underwent left nephrectomy for suspected left renal tumor. The surface of the left kidney was covered by numerous cysts. The result of pathological examination was renal cell carcinoma, which was recognized in a total of 7 regions of the left kidney. The patient remains well on hemodialysis, with no evidence of recurrence or metastasis.     

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.     

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.     

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.     

Non-traumatic retroperitoneal hemorrhage from renal adenoma]

A 37-year-old woman presented to our hospital with the chief complaints of stroke and sudden onset of pain in the left flank. An abdominal ultrasonogram showed a solid tumor and abdominal CT revealed a tumor 3 cm in diameter and a capsule with a heterogeneous interior at the left lower pole of the kidney. This tumor was accompanied by retroperitoneal hemorrhage. Selective left angiogram showed an avascular tumor with an artery entering the region surrounding the tumor itself. Based on the above mentioned findings, rupture of a renal angiomyolipoma was suspected. However, renal cancer could not be ruled out. Surgery was performed. At operation, a frozen section showed no malignancy, and partial nephrectomy was performed. The tumor measured 3.0 x 3.5 x 3.5 cm, and had a capsule that was 3 mm thick; its interior was filled with brown necrotic tissue mixed with red-brown coagulated blood. The histological diagnosis was a tubulo-papillary renal adenoma, but since the inside of the tumor had undergone extensive necrosis a well-differentiated adenocarcinoma could not be excluded. A renal adenoma manifesting clinical symptoms is rare, and this case of pain caused by retroperitoneal hemorrhage is the first to be reported in Japan. It is difficult to diagnose renal adenoma by preoperative imaging and intraoperative frozen section examination. Diagnosis is considered to be difficult in some cases even when examining permanent specimens. Therefore, the type of surgery used in affected patients should also be investigated in the future.     

Renal hemangiopericytoma discovered at a health screening: a case report

We report a case of renal hemangiopericytoma which was incidentally discovered by ultrasonography at a health screening. A 58-year-old man was admitted to our hospital for close examination of the renal tumor. Computed tomography revealed the left renal tumor, 60 x 50 mm in size, which was well enhanced with contrast medium. Magnetic resonance imaging revealed an isointensity mass (T1-weighted) and high-intensity mass (T2-weighted) at the left kidney. Radical nephrectomy was performed on suspicion of left renal cell carcinoma. Histopathological examination revealed renal hemangiopericytoma. The present case is the 7th in the Japanese literature.     

Basal Cell Carcinoma Occurring in Scar Tissue Following Excision of a Parotid Gland Pleomorphic Adenoma

BACKGROUND: A 49-year-old patient presented with a basal cell carcinoma growing on scar tissue left following excision of a parotid gland pleomorphic adenoma. OBJECTIVE: The objective was to determine whether the basal cell carcinoma had resulted from tumor spillage at the time of the pleomorphic adenoma excision. METHODS: Substantial evidence is presented linking the two tumors. RESULTS: The basal cell carcinoma most likely occurred as the result of tumor spillage at the time of the parotid gland pleomorphic adenoma excision. CONCLUSIONS: Cutaneous connective tissue stroma plays a significant role in determining the differentiation of basal cell carcinomas.     

Papillary renal cell carcinoma radiographically mimicking massive calcification

A 53-year-old male was referred to the Department of Urology, Hokkaido Kouseiren Kutchan Kousei Hospital for a left renal mass incidentally found by computed tomography. The tumor was 29 mm in diameter and showed ring-like calcification and heterogeneous enhancement by the contrast medium. The patient underwent left partial nephrectomy after the diagnosis of left renal cell carcinoma. Contrary to the radiographic finding, there was no palpable calcified lesion in the macroscopic specimen. Histopathologically, the tumor showed features of papillary renal cell carcinoma with massive psammoma bodies which might have been the cause for mimicking radiographic calcification.     

A case of unilateral and metachronous occurrence of renal tubulopapillary adenoma and renal cell carcinoma

A 50-year-old male underwent a nephron-sparing surgery for a small renal incidentaloma, which was atypical for renal cell carcinoma in diagnostic images. The tumor was pathologically diagnosed as renal tubulopapillary adenoma. Three years later, another tumor was pointed out in the ipsilateral kidney, and he underwent a radical nephrectomy. The latter was diagnosed as clear cell carcinoma. We report this very rare case of unilateral and metachronous occurrence of renal tubulopapillary adenoma and renal cell carcinoma.