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

No abstract available.
Adenoma, Bile Duct/pathology/*radiography ; Adult ; Aged ; Angiomyolipoma/pathology/*radiography ; Bile Duct Neoplasms/pathology/*radiography ; Bile Ducts, Intrahepatic ; Carcinoma, Hepatocellular/radiography ; Diagnosis, Differential ; Female ; Gadolinium DTPA/*chemistry ; Humans ; Liver Diseases/pathology/*radiography ; Liver Neoplasms/pathology/*radiography ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Pseudolymphoma/pathology/*radiography ; Tomography, X-Ray Computed

No abstract available.
Bone Marrow/*pathology/radiography/radionuclide imaging ; Carcinoma, Adenoid Cystic/*diagnosis ; Eye Neoplasms/*diagnosis ; Female ; Humans ; Lacrimal Apparatus/*pathology/radiography/radionuclide imaging ; Lacrimal Apparatus Diseases/*diagnosis ; Maxilla ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Recurrence, Local ; *Positron-Emission Tomography ; *Tomography, X-Ray Computed

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

We report on a case of a 57-year-old male who underwent a curative resection for hepatocellular carcinoma (HCC) with histological confirmation of a spontaneously necrotized tumor. Initial serum AFP level was 4,778 ng/mL. A 3.7 cm hyperechoic mass in segment 6 of the liver was observed on ultrasonography and dynamic contrast-enhanced liver MRI showed a 3.7x3.1 cm sized HCC. He was scheduled to undergo curative surgical resection under the clinical diagnosis of an early stage HCC (Barcelona Clinic Liver Cancer stage A). Without treatment, the serum AFP level declined rapidly to 50 ng/mL over five weeks. He underwent curative wedge resection of segment 6 of the liver. Histology revealed complete necrosis of the mass rimmed by inflamed fibrous capsule on a background of HBV-related cirrhosis with infiltration of lymphoplasma cells. Exact pathophysiology underlying this event is unknown. Among the proposed mechanisms of spontaneous neoplastic remission of HCC, circulatory disturbance and activation of host immune response offer the most scientific explanation for the complete histologic necrosis of HCC in the resected mass seen in our patient.
Carcinoma, Hepatocellular/*diagnosis/diagnostic imaging/pathology ; Hepatitis B/complications/diagnosis ; Humans ; Liver/diagnostic imaging/pathology ; Liver Cirrhosis/etiology ; Liver Neoplasms/*diagnosis/diagnostic imaging/pathology ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Necrosis ; Radiography ; Remission, Spontaneous ; Ultrasonography ; alpha-Fetoproteins/analysis

Imaging studies including magnetic resonance imaging (MRI) play a crucial role in the diagnosis and staging of hepatocellular carcinoma (HCC). Several recent studies reveal a large number of MRI features related to the prognosis of HCC. In this review, we discuss various MRI features of HCC and their implications for the diagnosis and prognosis as imaging biomarkers. As a whole, the favorable MRI findings of HCC are small size, encapsulation, intralesional fat, high apparent diffusion coefficient (ADC) value, and smooth margins or hyperintensity on the hepatobiliary phase of gadoxetic acid-enhanced MRI. Unfavorable findings include large size, multifocality, low ADC value, non-smooth margins or hypointensity on hepatobiliary phase images. MRI findings are potential imaging biomarkers in patients with HCC.
Aged ; Biological Products ; Biomarkers, Tumor ; Carcinoma, Hepatocellular/diagnosis/pathology/*radiography ; Contrast Media ; Gadolinium DTPA ; Humans ; Liver Neoplasms/diagnosis/pathology/*radiography ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Neoplasm Staging/methods ; Prognosis

PURPOSE: Ultrasound (US) and US-guided fine needle aspiration biopsies (FNAB) are considered the modalities of choice for assessing lymph nodes suspected of containing metastases, but the sensitivity of FNAB varies and is specific to the operator. We analyzed the risk of FNAB providing false negative results of lateral neck node metastasis, and evaluated diagnostic accuracy of FNAB, in patients with papillary thyroid cancer. MATERIALS AND METHODS: FNAB was performed in 242 patients suspected of having lateral neck node metastasis on preoperative imaging. Thyroglobulin in the fine-needle aspirate washout (FNA wash-out Tg) and computed tomography enhancement (Hounsfield units) were measured. Patients with negative results on FNAB were examined by intraoperative frozen section. The false negative and true negative groups were compared. RESULTS: Of the 242 patients, 130 were confirmed as having lateral neck node metastases. In 74 patients, the metastasis was identified by FNAB. False positive results were observed in 2 patients (0.8%) and false negatives in 58 (44.6%). Risk analysis showed that patient age <45 years (p=0.006), tumor size >1 cm (p=0.008) and elevated FNA wash-out Tg (p=0.004) were significantly associated with false negative results on FNAB. The accuracy of FNAB increased significantly when combined with FNA wash-out Tg (p=0.003). CONCLUSION: To reduce the false negative rate of FNAB, patient age (<45 years), tumor size (>1 cm) and FNA wash-out Tg (>34.8 ng/mL) should be considered in preoperative planning. Accuracy may be improved by combining the results of FNAB and FNA wash-out Tg.
Adolescent ; Adult ; Aged ; Biopsy, Fine-Needle ; Carcinoma/*diagnosis/*pathology/radiography/surgery ; False Negative Reactions ; Female ; Humans ; Lymph Nodes/*pathology/radiography ; Lymphatic Metastasis/*pathology/radiography ; Male ; Middle Aged ; Multivariate Analysis ; Preoperative Care ; Risk Factors ; Sensitivity and Specificity ; Thyroglobulin/metabolism ; Thyroid Gland/*pathology ; Thyroid Neoplasms/*diagnosis/*pathology/radiography/surgery ; Tomography, X-Ray Computed ; Young Adult

Hepatoblastoma usually occurs in children under the age of 2 years, with very few cases reported in adults. We experienced a case of adult hepatoblastoma in a 36-year-old female with chronic hepatitis B . She had experienced sudden onset abdominal pain. Her serum alpha-fetoprotein level was markedly elevated, and abdominal CT showed a 9-cm mass with internal hemorrhage in the right hepatic lobe with hemoperitoneum, so an emergency hepatic central bisectionectomy was performed. The initial histologic examination revealed that the mass mimicked combined hepatocellular carcinoma and cholangiocarcinoma with spindle-cell metaplasia of the cholangiocarcinoma element. Follow-up abdominal CT performed 3 months later showed a 5.5-cm metastatic mass in the left subphrenic area. Laparoscopic splenectomy with mass excision was performed, and hepatoblastoma was confirmed histologically. A histologic re-examination of previously obtained surgical specimens also confirmed the presence of hepatoblastoma. Metastatic hepatoblastoma was found at multiple sites of the abdomen during follow-up, and so chemotherapy with cisplatin, 5-fluorouracil (5-FU), and vincristine was applied, followed by carboplatin and doxorubicin . Despite surgery and postoperative chemotherapy, she died 12 months after symptom onset.
Adult ; Carcinoma, Hepatocellular/pathology ; Cholangiocarcinoma/pathology ; Cisplatin/therapeutic use ; Diagnostic Errors ; Doxorubicin/therapeutic use ; Drug Therapy, Combination ; Female ; Fluorouracil/therapeutic use ; Hepatitis B, Chronic/complications/diagnosis ; Hepatoblastoma/drug therapy/*pathology/radiography ; Humans ; Liver Neoplasms/drug therapy/*pathology/radiography ; Tomography, X-Ray Computed ; Vincristine/therapeutic use

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

Solitary metastases from colorectal carcinoma in the absence of hepatic or pulmonary metastases are rare. These can have a diverse imaging appearance, particularly after chemotherapy. It is important identify patients with solitary skeletal metastases, as they have a better prognosis than those with multiple skeletal or visceral metastases. We describe an unusual case of a solitary metastasis to the femur in a case of colon carcinoma that went undiagnosed and later presented with imaging features of osteogenic sarcoma.
Adult ; Bone Neoplasms/diagnosis/radiography/secondary ; Carcinoma/*diagnosis/pathology/radiography ; Colorectal Neoplasms/*diagnosis/pathology/radiography ; Female ; Femur/radiography ; Humans ; Magnetic Resonance Imaging ; Prognosis ; Tomography, X-Ray Computed