A case of tumor-forming chronic pyelonephritis that was difficult to be differentiated from renal cell carcinoma

We experienced a rare case of tumor-forming type of chronic pyelonephritis that could hardly be differentiated from renal cell carcinoma. A 62-year-old man was admitted to our department with right renal tumor which was discovered when he underwent examination for gastric cancer. Abdominal ultrasound sonography and computed tomography revealed a mass in the middle portion of the right kidney, measuring 3.8 x 3.5 cm in diameter, with irregular surface and isoechoic and isodense inner mass. Renal angiography demonstrated a hypervascular area in the middle portion. Radical nephrectomy and subtotal gastrectomy were performed under a tentative diagnosis of right renal cell carcinoma and early gastric cancer. The excised specimen macroscopically demonstrated a yellowish mass in the middle portion and microscopically revealed many lymphocytes and few neutrophils, macrophages or foam cells. The patient was diagnosed as tumor-forming type of chronic pyelonephritis. Such obvious inflammatory findings very rarely exist in the tumor-forming type of chronic pyelonephritis. Therefore, caution should be exercised in the differential diagnosis between this disease and renal cell carcinoma.     

A case of renal cell carcinoma with the complication of a giant cyst difficult to distinguish from xanthoma

A case of renal cell carcinoma accompanied by a giant cyst in a 69-year-old male patient is reported. The patient consulted a physician in our Hospital for bellyache on the left abdomen. Because giant cyst in the left kidney and intracystic hemorrhage were suspected by computed tomography diagnosis, the patient was transferred to the Department of Urology, As a tumor-like mass was detected in the cyst by ultrasound echo diagnosis, transperitoneal extirpation of the left kidney was conducted on May 8, 1985. At operation, a giant unilocular cyst covered with hypertrophic fibrous capsule including much coagula was observed. The inner wall of the cyst was covered with many deeply yellow torous lesions of sizes ranging from those of a wheat grain to thumb. Histologically, the lesions consisted of a cell group supposedly of histiocyte origin accompanied by cellular infiltration of lymph cells, and xanthoma was deeply suspected. However, as it was difficult to distinguish from the clear cell subtype of renal cell carcinoma, examination by an electron microscope was conducted and the final diagnosis of renal cell carcinoma was made. The post-operative course of the patient was good and no recurrence or cancer metastasis was observed as of January, 1986.     

A prostatic duct carcinoma difficult to distinguish from transitional cell carcinoma: a case report

A 77-year-old male with a complaint of dysuria and gross hematuria for 3 months visited our hospital. Abdominal ultrasonography, computed tomographic scan and magnetic resonance imaging revealed a prominent tumor from the bladder neck. Serum prostate specific antigen (PSA) level was high (1,130 ng/ml) suggesting prostate cancer, but transitional cell carcinoma (TCC) was detected by transurethral biopsy. Bone scintigraphy revealed multiple bone metastasis. Since gross hematuria requiring bladder tamponade continued, simple cystoprostatectomy and cutaneous ureterostomy were performed. Pathological findings showed prostatic acinar carcinoma and prostatic duct carcinoma mimicking TCC, and PSA immunohistochemically weak positive. The final diagnosis was prostate cancer consisting of acinar and ductal component. Adjuvant hormonal therapy was performed, but was ineffective. The patient died 2.5 months after operation. We reviewed and discussed 66 cases of prostatic duct carcinoma, including our case, in the Japanese literature.     

A case of infiltrating transitional cell carcinoma of kidney difficult to distinguish from xanthogranulomatous pyelonephritis

The patient, a 67-year-old man, initially visited another institution with asymptomatic macroscopic hematuria as the major complaint. Since imaging revealed a tumor occupying the left kidney, he was referred to our hospital. Computed tomography (CT) was suggestive of a tumor involving the renal pelvis that had infiltrated the renal parenchyma. The patient was scheduled for surgery, which was postponed when pre-operative CT indicated a reduction in the tumor size, leading to a subsequent diagnosis of xanthogranulomatous pyelonephritis. Surgery was eventually conducted to address complaints such as persistent hematuria. The pathological diagnosis was infiltrating transitional cell carcinoma of the kidney. Urinary cytodiagnoses were class II-III throughout the observation period.     

A case of tuberculous epididymitis which was difficult to distinguish from a testicular tumor

A 70-year-old man complaining of painless right scrotal swelling was referred to our hospital. He had a past history of left nephrectomy for renal tuberculosis at the age of 28. Power Doppler ultrasonography revealed a hypoechoic and hypovascular tumor with septa in the scrotum. We suspected a right testicular tumor and therefore, performed a right high inguinal orchiectomy. On macroscopic findings, the fluid of the tumor was yellowish and mucinous and the ipsilateral testis was remarkably atrophic. The pathological diagnosis was tuberculous epididymitis with central necrosis. In recent years, tuberculous epididymitis is rare, and this case was considered to be the first report of power Doppler ultrasonographic findings in tuberculous epididymitis.     

A case of focal xanthogranulomatous pyelonephritis difficult to differentiate from renal cell carcinoma

A 34-year-old female with left flank pain persisting for 3 months consulted us on 19 Feb, 2001. Ultrasonography (US), computerized tomography (CT), magnetic resonance imaging (MRI) and renal angiography revealed a cystic renal tumor in the upper pole of the left kidney invading the spleen, and paraaortic lymph node swelling. Left radical nephrectomy combined with splenectomy and partial diaphragmectomy was performed under a tentative diagnosis of renal cell carcinoma. However, histopathological findings revealed xanthogranulomatous pyelonephritis (XGP). XGP is a rare, severe, chronic inflammatory disease characterized by accumulation of lipid laden macrophages. XGP is classified as diffuse or focal type. Preoperative diagnosis of focal XGP is difficult because of radiological similarities to renal cell carcinoma. Our case was more difficult to diagnose because she showed few signs of inflammation and had no history of urinary tract infection or stones.     

A case of abdominal desmoid tumor that was difficult to differentiate from urachal tumor

A 76-year-old male patient complained of frequent urination. Computed tomographic and magnetic resonance imaging scans revealed a heterogeneous mass involving his bladder, prostate and Sigmoid colon. He was diagnosed with an invasive urachal tumor and surgery was performed due to severe tumor adhesion to adjacent organs. Partial resection of the tumor was performed with partial cystectomy and sigmoidectomy. A post-operative pathological diagnosis revealed the tumor was a desmoid abdominal wall tumor. The desmoid abdominal wall tumor was not easily differentiated preoperatively from an urachal tumor.     

A case report of spontaneous rupture of renal cell carcinoma difficult to be distinguished from angiomyolipoma

A 56-year-old woman was admitted with right flank pain as the chief complaint without any trauma. Abdominal and chest computed tomography (CT scan) demonstrated with low-density area in a retroperitoneal hematoma suspected of spontaneous rupture of angiomyolipoma and hematothorax. Superselective transarterial embolization and drainage of the thoracic cavity were performed. Three months later a right renal tumor in perirenal hematoma was revealed by abdominal CT scan and suspected renal cell carcinoma. Right nephrectomy was performed. Histopathology revealed renal cell carcinoma. Including this case, 31 cases of spontaneous rupture of renal cell carcinoma have been reported in the Japanese literature.     

A case of retroperitoneal teratoma difficult to distinguish from adrenal myelolipoma

A 59-year-old man presented to our hospital suspected of having cholelithiasis. Computed tomography (CT) scan revealed a left retroperitoneal solid tumor cephalad to the kidney, 7 x 8 x 9 cm in size with mostly a fatty density area and focal calcification. Magnetic resonance imaging (MRI) on T1 and T2 weighted images showed a high intensity mass. Angiography revealed the hypovascular tumor. Although we had suspected it to be an adrenal myelolipoma, tumorectomy was performed because of its size. Pathological diagnosis was mature teratoma. Although retroperitoneal teratoma contains fas, cyst, soft tissue and calcification, the proportion of fat in the tumor is usually less than that of adrenal myelolipoma. In our case, the tumor contained more fat than the 'typical' retroperitoneal teratoma, which led to the misdiagnosis.     

Lymphoepithelial cyst of the pancreas that was difficult to distinguish from branch duct-type intraductal papillary mucinous neoplasm: Report of a case

A 58-year-old woman was admitted to our hospital to optimize the management of her diabetes mellitus. A computed tomography (CT) scan showed a 30-mmdiameter, multilocular cyst in the head of the pancreas. The tumor markers, including DUPAN 2, SPAN-1, and carbohydrate antigen 19-9, were within the normal ranges. A contrast-enhanced CT scan showed a nonenhanced, multilocular cyst. Abdominal magnetic resonance imaging showed a multilocular cyst. Endoscopic retrograde cholangiopancreatography showed that the main pancreatic duct was normal. Based on these findings, we suspected a branch duct type intraductal papillary mucinous neoplasm. A distal pancreatectomy with a splenectomy was performed, since more of the mass was located on the dorsolateral side, inconsistent with the preoperative imaging results. On the resected specimen, a 4-cm-diameter, multilocular cyst containing serous fluid was found. Pathologically, the cyst wall was lined with squamous epithelium surrounded by abundant lymphoid tissue with follicles, consistent with a lymphoepithelial cyst of the pancreas, which is an unusual benign cyst.     

A case of renal cell carcinoma difficult to diagnose preoperatively because of hypovascular findings

A 35-year-old man visited our out-patient clinic with the chief complaint of macroscopic hematuria. After admission to the hospital, examinations by CT scan, renal angiography, etc. revealed a hypovascular space-occupying lesion in the right kidney, but no definite diagnosis could be made; blood findings such as accentuated alpha 2-globulin and raised LDH suggested the possibility of malignancy; and right nephrectomy was performed. In view of the preoperative X-ray findings together with postoperative pathological findings, papillary renal cell carcinoma was suspected intensively. Some discussion was made on the differentiation of lesions of hypovascular to avascular tumors and the reliability of image diagnosis based on CT scan, angiography, and other methods.     

A case of inflammatory pseudotumor of the urinary bladder that was difficult to differentiate from sarcoma

On September 25th, 2003, a 39-year-old man complained of asymptomatic gross hematuria. He was admitted to a nearby hospital and evaluated. Cystoscopy revealed a non-papillary broad base tumor in the anterior wall of the bladder. On October 2nd, a TUR-Bt was performed. The pathological diagnosis was difficult to determine because mitosis and nuclear pleomorphism were apparent. He next came to our hospital for further evaluation. We diagnosed his condition as an inflammatory pseudotumor of the bladder because fibroblasts and inflammatory cells had increased; however, we did not see abnormal nuclear mitosis or severe pleomorphism. Although we did not perform a complete TUR-Bt, the mass regressed spontaneously and did not reoccur. The presence of mitosis and mild nuclear pleomorphisms make certain cases difficult to diagnose as inflammatory pseudotumors. Inflammatory pseudotumors are generally considered benign, and some cases regress spontaneously. It is important that we are able to identify and characterize these pseudotumors in order to avoid more invasive surgeries whenever possible.     

True thymic hyperplasia which was difficult to distinguish from malignancy in adult; report of a case

We report a case of 45-year-old man with true thymic hyperplasia. Three years earlier he had undergone operation for carcinoma of the floor of mouth. He had no symptoms but had been pointed out an anterior mediastinal mass on chest computed tomography (CT). Chest CT revealed a well defined solid mass in front of the ascending aorta. The mass showed sail sign. The size of this mass did not increase on a follow-up chest CT. The signal intensity of this mass was slightly inhomogeneous on chest magnetic resonance imaging (MRI). No invasion of the surround tissues was observed. Since the possibility of thymoma or other malignancy, extended thymectomy under median sternotomy was performed. His postoperative course was uneventful. Histopathological examination revealed true thymic hyperplasia.     

A case of renal cell carcinoma suspected of multilocular cystic nephroma

A 52-year-old, healthy looking woman was referred for further evaluation of left renal mass, She had had a history of hematuria for ten years. Admission laboratory studies were within normal limits except for slight elevation of white blood cell count, c-reactive protein, blood sedimentation rate and immunosuppressive acidic protein. Retrograde pyelography demonstrated a large mass with ringed calcification in the middle lobe of the left kidney. The multiloculated mass was also confirmed by computed tomography and ultrasonography. Selective left renal arteriography showed stretched arteries and irregularity and tortuosity of the smaller vessels. Under a presumptive diagnosis of multilocular cystic nephroma or renal cell carcinoma, left radical nephrectomy was performed. In surgical specimen, many lobules were filled with serous fluid and clotted blood. Microscopic examination revealed that the lining of the cyst wall consisted of renal cell carcinoma cell. At present, 5 months after the operation, she is well without any signs or symptoms of recurrence.     

A case of ureterovesical malacoplakia that manifested hydronephrosis

A 70-year-old woman visited a nearby physician with a chief complaint of fever and was admitted to a hospital with a diagnosis of acute pyelonephritis. After discharge, pyuria persisted and examination revealed an intravesical solid tumor. The patient was referred to this department for close examination and treatment. The right kidney was hydronephrotic. The intravesical tumor that was resected was solid yellowish-white and ranged from the neck of the uterus to both ureteral orifices. In addition, a grain-sized tumoral lesion, was found in the lower part of the ureter and was also resected. There was sclerotic thickening localized to the right intramural ureter, which had a slightly edematous interior. This was considered to be the cause of the hydronephrosis and a ureteral stent was put in place. Pathological diagnosis was given as malacoplakia. With this case, placement of a ureteral stent was chosen based on the findings of a minimal ureteral lesion, a narrow area of scarring in the intramural ureter as a probable cause of hydronephrosis, and a judgement of mild obstruction. A stent is less invasive for patients, but consideration should be given to urinary infection due to long-term placement recurrence of malacoplakia due to the increased risk of infection, and trouble with periodical exchanging of catheters due to aggravated scarring. Absence of pyuria or signs of recurrence after seven months' placement suggests that use of the stent was the best method.     

Emphysematous giant bulla that was difficult to differetiated from pneumothorax

We experienced 2 patients who admitted to our hospital becaus of acute onset of dyspnea and chest pain. Chest X-ray and chest computed tomography showed severe atelectasisi of hemilateral lung. After intathoracic drainage under local anesthesia, we diagnosed a emphysematous giant bulla. We resected the giant bulla.     

A case of renal cell carcinoma which was left untouched for five years

We report a case of bilateral synchronous renal cancers for which only right radical nephrectomy was performed at another hospital. Five years later we performed partial nephrectomy (enucleation) for the left renal cancer. By computed tomographic scans we studied the radiological change of this tumor which occurred during a five-year period. We found a slow doubling time of this tumor. Three years after enucleation, tumor recurrence was noticed and we performed left partial nephrectomy with a normal parenchymal margin. We reviewed the literature about enucleation of renal cancer.     

Multilocular cystic renal cell carcinoma: report of a case

We report a case of multilocular cystic renal cell carcinoma seen in a 54-year-old man. At the annual health check he was found to have numerous cysts of various sizes in the lower pole of the left kidney. Plain CT scan disclosed a mass in the lower pole of the left kidney. On enhanced CT scan septa were visible, suggesting a multilocular cyst. Left renal arteriography disclosed a hypervascular mass in the lower pole of the left kidney. Radical nephrectomy was performed. The gross appearance of the cut surface showed a feature of multilocular cyst. The histopathological diagnosis was clear cell carcinoma. We describe the clinical features of multilocular cystic renal cell carcinoma and discuss the differential diagnosis.     

A case of cystic renal cell carcinoma: clinical usefulness of CT arteriography

We report a case of cystic renal cell carcinoma (CRCC). In general, computed tomography (CT) and magnetic resonance imaging (MRI) are sufficient for diagnosing renal cell carcinoma (RCC). However, we often have difficulty in diagnosing CRCC based on these modalities alone. In the present case, to assess the contrast-enhancement of the cyst wall and the septum, we evaluated the usefulness of CT arteriography (CTA) by selective injection of contrast material into the renal artery. We believe that CTA could be a valid option for preoperative radiological differentiation of CRCC.     

获得性肾囊性疾病合并肾癌11例临床分析

目的 探讨获得性肾囊性疾病(ACKD)合并肾癌的诊断治疗策略.方法 回顾性分析11例终末期肾衰竭、获得性肾囊肿合并肾癌患者的临床资料.男8例,女3例.平均年龄55(37～68)岁.行血液透析至发现肾脏病变时间平均为4.8(2.8～7.4)年.结果 11例均行肾癌根治术.术后病理报告:透明细胞癌3例,乳头状癌6例,嫌色细胞癌1例,乳头状腺瘤1例.病理分期T1a9例,T1b 2例.11例术后随访平均55(17～83)个月.1例术后24个月发现肺转移;1例单侧发病者术后22个月对侧复发,行肾癌根治术;1例死于心血管疾病;1例随访19个月后失访;无瘤生存7例.结论 ACKD与肾癌有较高的相关性.终末期肾衰竭患者透析前氮质血症时间较长或透析时间＞3年者,应排除ACKD.超声及CT检查对早期诊断存在价值.除关注ACKD恶性变倾向外,对长期肾衰竭患者的其他并发症如心脑血管疾病、糖尿病等也应足够重视并行积极治疗.

Abstract：

Objective To discuss the diagnosis and treatment of acquired cystic kidney disease complicated by kidney cancer. Methods Clinical data of 11 patients with acquired cystic kidney disease complicated by kidney cancer were analyzed retrospectively. Eight patients were male and three were female. The mean age was 55 years old (range 37 to 68). The time of hemodialysis ranged from 2.8 to 7. 4 years, mean 4. 8 years. Results Follow-up ranged from 17- 83 months, mean 55 months. One patient died of cardiovascular disease. Lung metastasis was detected in one patient two years after surgery. Seven patients survived free of tumor recurrence and there was no follow-up on one patient. Conclusions Increased incidence of cancer was observed in patients with end-stage renal disease who have undergone long-term dialysis. In particular, renal cell carcinoma (RCC) showed an excess incidence in ACKD patients. RCC showed an increased prevalence compared with the general population. Patients with predialysis azotemia or a dialysis duration of longer than 3 years should be screened for ACKD. Sonegraphy or CT scanning are useful for early diagnosis of ACKD. We should pay close attention to complications, including ACKD malignant tendency, in patients who have been taking long-term dialysis and positive therapy.