PURPOSE: To investigate and distinguish the computed tomography (CT) characteristics of chromophobe renal cell carcinoma (chRCC) and renal oncocytoma. MATERIALS AND METHODS: Fifty-one patients with renal oncocytoma and 120 patients with chRCC, diagnosed by surgery between November 2005 and June 2015, were studied retrospectively. Two observers, who were urologists and unaware of the pathological results, reviewed the preoperative CT images. The tumors were evaluated for size, laterality, tumor type (ball or bean pattern), central stellate scar, segmental enhancement inversion, and angular interface pattern and tumor complexity. To accurately analyze the mass-enhancing pattern of renal mass, we measured Hounsfield units (HUs) in each phase and analyzed the mean, maximum, and minimum HU values and standard deviations. RESULTS: There were 51 renal oncocytomas and 120 chRCCs in the study cohort. No differences in clinical and demographic characteristics were observed between the two groups. A central stellate scar and segmental enhancement inversion were more likely in oncocytomas. However, there were no differences in ball-/bean-type categorization, enhancement pattern, and the shape of the interface between the groups. Higher HU values tended to be present in the corticomedullary and nephrogenic phases in oncocytomas than in chRCC. Receiver-operating characteristic curve analysis showed that the presence of a central stellate scar and higher mean HU values in the nephrogenic phase were highly predictive of renal oncocytoma (area under the curve=0.817, p<0.001). CONCLUSIONS: The appearance of a central stellate scar and higher mean HU values in the nephrogenic phase could be useful to distinguish renal oncocytomas from chRCCs.
Adenoma, Oxyphilic/pathology/*radiography ; Carcinoma, Renal Cell/pathology/*radiography ; Diagnosis, Differential ; Female ; Humans ; Kidney Neoplasms/pathology/*radiography ; Male ; Middle Aged ; Retrospective Studies ; Tomography, X-Ray Computed

OBJECTIVE: To describe computed tomography (CT) features of metastatic gallbladder (GB) tumors (MGTs) from various primary tumors and to determine whether there are differential imaging features of MGTs according to different primary tumors. MATERIALS AND METHODS: Twenty-one patients who had pathologically confirmed MGTs and underwent CT were retrospectively enrolled. Clinical findings including presenting symptoms, type of surgery, and interval between primary and metastatic tumors were recorded. Histologic features of primary tumor and MGTs including depth of invasion were also reviewed. Imaging findings were analyzed for the location and morphology of MGTs, pattern and degree of enhancement, depth of invasion, presence of intact overlying mucosa, and concordance between imaging features of primary and metastatic tumors. Significant differences between the histologies of MGTs and imaging features were determined. RESULTS: The most common primary tumor metastasized to the GB was gastric cancer (n = 8), followed by renal cell carcinoma (n = 4) and hepatocellular carcinoma (n = 3). All MGTs (n = 21) manifested as infiltrative wall thickenings (n = 15) or as polypoid lesions (n = 6) on CT, similar to the features of primary GB cancers. There were significant differences in the morphology of MGTs, enhancement pattern, enhancement degree, and depth of invasion according to the histology of primary tumors (p < 0.05). Metastatic adenocarcinomas of the GB manifested as infiltrative and persistently enhancing wall thickenings, while non-adenocarcinomatous metastases usually manifested as polypoid lesions with early wash-in and wash-out. CONCLUSION: Although CT findings of MGTs are similar to those of primary GB cancer, they are significantly different between the various histologies of primary tumors.
Adenocarcinoma/pathology/radiography/secondary ; Adult ; Aged ; Carcinoma, Hepatocellular/pathology/radiography/secondary ; Carcinoma, Renal Cell/pathology/radiography/secondary ; Carcinoma, Squamous Cell/pathology/radiography/secondary ; Diagnosis, Differential ; Female ; Gallbladder Neoplasms/pathology/*radiography/*secondary ; Humans ; Kidney Neoplasms/pathology ; Liver Neoplasms/pathology ; Male ; Melanoma/pathology/radiography/secondary ; Middle Aged ; Neoplasm Invasiveness/radiography ; Retrospective Studies ; Stomach Neoplasms/pathology ; *Tomography, X-Ray Computed

Although recently, there have been introduced many new diagnostic tools such as renal scanning and renogram, intravenous urogram remains to be one of the most useful method of urological diagnosis. Therefore it seems warranted to review 363 cases of intravenous urograms performed in the department of urology, St. Mary's hospital, Catholic Medical College during the period of January, 1962 to June, 1964. Among others, especial attention was paid to 60 cases of nonvisualizing kidneys. Of 60 nonvisualizing kidneys, renal tuberculosis occupied 27 cases(45%); ureteral and renal stones 13(21.6%); hydronephrosis 9(15%) (metastatic carcinoma 6(10%)and surgical manipulation 3(5%); Wilms' tumor 5 (8.3%) chronic atrophic pyelonephritis 3(5%) ; One case each of renal cell carcinoma, cystic kidney and thrombosis of the renal artery. Inasmuch as the present study revealed renal tuberculosis to be the most common cause of nonvisualizing kidneys, it is felt that one should always consider the possibility of tuberculosis in the diagnosis of nonvisualizing kidneys in Korea. This fact should be stressed because nontuberculous pathology such as chronic pyelonephritis has been implicated to be the most frequent cause of nonvisualizing kidneys by American authors.
Carcinoma, Renal Cell ; Diagnosis ; Hydronephrosis ; Kidney Diseases, Cystic ; Kidney* ; Korea ; Pathology ; Pyelonephritis ; Radiography* ; Renal Artery ; Thrombosis ; Tuberculosis ; Tuberculosis, Renal ; Ureter ; Urology ; Wilms Tumor

A 61-year-old man presented with a right renal mass with a vena caval thrombus on computed tomography that was consistent with renal cell carcinoma. The results of routine laboratory examinations and urinalysis were within normal limits. Preoperative planning was critical owing to the presence of the vena caval thrombus. A radical nephrectomy, vena caval thrombectomy, and regional lymphadenectomy were done. The pathologic report was consistent with a high-grade, invasive urothelial carcinoma, with sarcomatoid differentiation involving the renal vein and inferior vena cava (Stage IV, T4N0M0). Thus, this was a rare case of upper tract urothelial carcinoma. Adjuvant chemotherapy with the methotrexate, vinblastine, doxorubicin, cisplatinum regimen is scheduled. To our knowledge, this is the first report in Korea of upper tract urothelial carcinoma of the sarcomatoid type with a vena caval thrombus.
Carcinoma, Renal Cell/pathology ; Diagnosis, Differential ; Humans ; Kidney Neoplasms/diagnosis/*pathology ; Lymph Node Excision/methods ; Male ; Middle Aged ; Nephrectomy/methods ; Renal Veins/*radiography ; Thrombectomy/methods ; Thrombosis/*radiography ; Tomography, X-Ray Computed ; Vena Cava, Inferior/*radiography

A 61-year-old man presented with a right renal mass with a vena caval thrombus on computed tomography that was consistent with renal cell carcinoma. The results of routine laboratory examinations and urinalysis were within normal limits. Preoperative planning was critical owing to the presence of the vena caval thrombus. A radical nephrectomy, vena caval thrombectomy, and regional lymphadenectomy were done. The pathologic report was consistent with a high-grade, invasive urothelial carcinoma, with sarcomatoid differentiation involving the renal vein and inferior vena cava (Stage IV, T4N0M0). Thus, this was a rare case of upper tract urothelial carcinoma. Adjuvant chemotherapy with the methotrexate, vinblastine, doxorubicin, cisplatinum regimen is scheduled. To our knowledge, this is the first report in Korea of upper tract urothelial carcinoma of the sarcomatoid type with a vena caval thrombus.
Carcinoma, Renal Cell/pathology ; Diagnosis, Differential ; Humans ; Kidney Neoplasms/diagnosis/*pathology ; Lymph Node Excision/methods ; Male ; Middle Aged ; Nephrectomy/methods ; Renal Veins/*radiography ; Thrombectomy/methods ; Thrombosis/*radiography ; Tomography, X-Ray Computed ; Vena Cava, Inferior/*radiography

The prevalence of small renal masses (SRM) has risen, paralleling the increased usage of cross-sectional imaging. A large proportion of these SRMs are not malignant, and do not require invasive treatment such as nephrectomy. Therefore, differentation between early renal cell carcinoma (RCC) and benign SRM is critical to achieve proper management. This article reviews the radiological features of benign SRMs, with focus on two of the most common benign entities, angiomyolipoma and oncocytoma, in terms of their common imaging findings and differential features from RCC. Furthermore, the role of percutaneous biopsy is discussed as imaging is yet imperfect, therefore necessitating biopsy in certain circumstances to confirm the benignity of SRMs.
Abdominal Fat/pathology ; Adenoma, Oxyphilic/diagnosis/radiography/ultrasonography ; Angiomyolipoma/diagnosis/radiography/ultrasonography ; Carcinoma, Renal Cell/*diagnosis/radiography/ultrasonography ; Diagnosis, Differential ; Humans ; Kidney Neoplasms/*diagnosis/*radiography/ultrasonography ; Leiomyoma/diagnosis/radiography/ultrasonography

Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma.
Bone Neoplasms/secondary ; Carcinoma, Renal Cell/pathology/radiography ; Diagnosis, Differential ; Fibrosarcoma/radiography ; Histiocytoma/radiography ; Humans ; Kidney Neoplasms/*pathology/radiography ; Leiomyosarcoma/pathology/radiography ; Magnetic Resonance Imaging ; Middle Aged ; Neuroectodermal Tumors, Primitive/pathology/radiography ; Osteosarcoma/pathology ; Sarcoma ; Sarcoma, Synovial/radiography ; Tomography, X-Ray Computed

Renal cell carcinoma (RCC) with mucin production is extremely rare. We present the case of a previously healthy 76-year-old woman who underwent a robotic-assisted laparoscopic right nephrectomy for a 5-cm heterogeneously enhancing right renal mass. Pathology revealed mucin-producing epithelial RCC. We discuss the presentation and pathological features of this case and comment on its definitive treatment.
Adenocarcinoma, Mucinous/*pathology/radiography/surgery ; Aged ; Carcinoma, Renal Cell/*pathology/radiography/surgery ; Female ; Humans ; Kidney Neoplasms/*pathology/radiography/surgery ; Nephrectomy/methods ; Robotic Surgical Procedures/methods ; Tomography, X-Ray Computed

The spontaneous regression of metastatic lesions from renal cell carcinoma (RCC) is extremely rare, but may be encountered following cytoreductive treatments. We report a case of a recurrent RCC with multiple metastatic lesions which spontaneously regressed after undergoing radiofrequency ablation of the renal tumor.
Adrenal Gland Neoplasms/radiography/*secondary ; Aged, 80 and over ; Carcinoma, Renal Cell/radiography/*secondary/*surgery ; *Catheter Ablation ; Humans ; Kidney Neoplasms/*pathology/radiography/*surgery ; Lung Neoplasms/radiography/*secondary ; Male ; Neoplasm Recurrence, Local ; Remission, Spontaneous ; Tomography, X-Ray Computed

An adenocarcinoma arising in a horseshoe kidney (HK) is rare. The case of a forty five-year-old male patient, presenting with a recurrent, painless hematuria, is reported. On investigation the patient was found to have a horseshoe kidney, with an adenocarcinoma in the left hemi-kidney, which was treated surgically, with a hemi-nephrectomy, of the involved part, being performed to excise the tumor. A brief review of the relevant literature is also presented.
Carcinoma, Renal Cell/*complications/pathology/surgery ; Human ; Kidney/*abnormalities/radiography ; Kidney Neoplasms/*complications/pathology/surgery ; Lymph Node Excision ; Male ; Middle Aged ; Nephrectomy/methods