Wenxin Chen

Comparative study of CT appearances in renal oncocytoma and chromophobe renal cell carcinoma

Background Renal oncocytoma (RO) and chromophobe renal cell carcinoma (ChRCC) share histologic and some imaging features. Purpose To investigate the multidetector computed tomography (MDCT) characteristics of these two tumor types. Material and Methods Fifty-six patients with RO and 54 patients with ChRCC were studied retrospectively. MDCT was undertaken to investigate differences in tumor characteristics. Results Calcifications were visible in 24 (42.8%) patients with RO and in 11 (20.4%) patients with ChRCC (P = 0.011). 26 patients with RO had stellate scars as did 14 patients with ChRCC (P = 0.025). Spoken-wheel-like enhancement was visible in 41 patients with RO and in 11 with ChRCC (P < 0.001). Thirty-nine (69.6%) patients with RO and nine (16.7%) patients with ChRCC showed segmental inversion (P < 0.001). Two patients with RO had retroperitoneal lymph node enlargement as did 13 patients with ChRCC (P = 0.002). Combined evaluation of stellate scar, spoken-wheel-like enhancement, and segmental enhancement inversion features were found to have a sensitivity of 99.1% (106 of 107), a specificity of 100% (3 of 3), a positive predictive value of 100% (106 of 106), and a negative predictive value of 75% (3 of 4). The attenuation of RO tumors was greater than that of ChRCC tumors, normal renal parenchyma on unenhanced CT (P = 0.031). Enhancement was higher with RO than with ChRCC tumors in all phases (P = 0.021, < 0.001, and 0.007, respectively). Conclusion CT imaging features such as stellate scar, spoken-wheel-like enhancement, and segmental enhancement inversion were more common in RO and they may help in differentiating RO from ChRCC.

The clinical and CT imaging features of metanephric adenoma.

Background Patients with metanephric adenoma have a good prognosis after undergoing total nephrectomy or local resection with kidney preservation. Accurate diagnosing is important for guiding clinical treatment. Only few previous case reports have been found focusing on the imaging findings of metanephric adenoma. Purpose To evaluate the multislice computed tomography (MSCT) imaging characteristics of metanephric adenoma. Material and Methods The imaging findings in eight patients with metanephric adenoma were studied retrospectively. MSCT was undertaken to investigate tumor location, size, attenuation, cystic or solid appearance, calcification, capsule sign, and enhancement pattern. Results Tumors (mean diameter, 3.3 ± 1.0 cm) were solitary (8/8), solid (7/8) with cystic components (2/8), no calcifications (7/8), had a poorly-defined margin (8/8), were centered in the renal medulla (7/8), compressed the renal pelvis (3/8), and none had retroperitoneal lymph node metastasis. The attenuation of metanephric adenoma tumors was less or equal compared to the renal cortex or medulla on unenhanced CT (30.6 ± 2.6 vs. 36.3 ± 4.6 vs. 33.2 ± 3.9, P > 0.05), while tumor enhancement after administration of an contrast agent was lower than that of normal renal cortex and medulla during all phases (P < 0.05). Conclusion Metanephric adenoma tends to be a solitary, poorly defined margin, isodense or hypodense mass arising from the renal medulla with enhancement less than the cortex and medulla during all phases.

The MSCT and MRI findings of collecting duct carcinoma

AIM To characterize the multi-section computed tomography (MSCT) and magnetic resonance imaging (MRI) features of collecting duct carcinoma (CDC). MATERIALS AND METHODS Twenty patients with CDC were studied retrospectively using MSCT (n = 20), and MSCT and MRI (n = 5). MSCT and MRI were undertaken to investigate tumour location, size, radiodensity, cystic or solid appearance, calcification, capsule, signal, enhancement pattern, and metastases. RESULTS Tumours (mean diameter 3.6 ± 1.7 cm) were solitary (20/20), solid (18/20), had cystic components (12/20), calcifications (12/20), poorly defined (18/20), were centred in the medulla (20/20), compressed the renal pelvis (12/20), and had lymph node metastases (2/20). On unenhanced computed tomography (CT), the radiodensity of the CDC was greater than that of the normal renal cortex or medulla (43.8 ± 2.4 versus 37.6 ± 5.1 or 32.6 ± 4.1, p = 0.041, n = 20). Five patients with CDC underwent MRI, which revealed cystic components (4/5), poorly defined CDC (5/5), and none of the patients had lymph node metastasis. The CDC was isointense on T1-weighted imaging, and iso- or hypointense on T2-weighted imaging. Enhancement was lower within the CDC than the renal cortex and medulla during all enhanced phases (p = 0.032, 0.001, 0.018, respectively, n = 20). CONCLUSION CDC should be considered when a renal tumour is centred in the medulla, with increased radiodensity on unenhanced CT and reduced enhancement compared to the adjacent cortex or medulla.

Comparative study of intestinal tuberculosis and primary small intestinal lymphoma

AIM To characterize the clinical, radiological, endoscopic and pathological features of intestinal tuberculosis (ITB) and primary small intestinal lymphoma (PSIL). METHODS This was a retrospective study from February 2005 to October 2012 of patients with a diagnosis of ITB (n = 41) or PSIL (n = 37). All patients with ITB or PSIL underwent computed tomography (CT) and pathological examination. Thirty-five patients with ITB and 32 patients with PSIL underwent endoscopy. These patients were followed for a further 18 mo to ascertain that the diagnosis had not changed. Clinical, endoscopic, CT and pathological features were compared between ITB and PSIL patients. RESULTS Night sweating, fever, pulmonary TB and ascites were discovered significantly more often in ITB than in PSIL patients (P < 0.05), however, abdominal mass, hematochezia and intestinal perforation were found significantly more frequently in PSIL than in ITB patients (P < 0.05). Ring-like and rodent-like ulcers occurred significantly more often in ITB than in PSIL patients (P < 0.05), however, enterorrhagia and raised lesions were significantly more frequent in PSIL than in ITB patients (P < 0.05). The rate of granuloma was significantly higher in ITB than in PSIL patients (87.8% vs 13.5%, χ(2) = 43.050, P < 0.05), and the incidence of confluent granulomas with caseous necrosis was significantly higher in ITB than in PSIL patients (47.2% vs 0.0%, χ(2) = 4.034, P < 0.05). Multi-segmental lesions, mural stratification, mural gas sign, and intestinal stricture were more frequent in ITB than in PSIL patients (P < 0.05), however, a single-layer thickening of bowel wall, single segmental lesions, and intussusception were more common in PSIL than in ITB patients (P < 0.05). Necrotic lymph nodes, comb sign and inflammatory mass were more frequent in ITB than in PSIL patients (P < 0.05). The bowel wall enhancement in ITB patients was greater than that in PSIL patients (P < 0.05), while the thickening and lymph node enlargement in PSIL patients were higher than those in ITB patients (P < 0.05). CONCLUSION Combined evaluation of clinical, radiological, endoscopic and pathological features is the key to differentiation between ITB and PSIL.

CT and MRI imaging features and long-term follow-up of adult Wilms' tumor.

Background Only few previous case reports have been found focusing on the imaging findings of adult Wilms’ tumor (WT). Purpose To characterize multislice computed tomography (MSCT), magnetic resonance imaging (MRI) characteristics, and follow-up results of adult WT. Material and Methods Sixteen patients with WT were studied retrospectively. MSCT and MRI were undertaken to investigate the tumor characteristics. Results Tumors (mean diameter, 13.1 ± 4.5 cm) exhibited an expansible appearance and disrupted the reniform contour (16/16), cystic components (16/16), curvilinear calcification (1/16), poorly marginated (2/16), hemorrhage (16/16), displacement of renal pelvis or calyx (13/16), and had lymph node or distal metastases (5/16). Attenuation of WT was less or equal compared to renal parenchyma on unenhanced CT (P > 0.05), while tumor enhancement after administration of a contrast agent was lower than that of normal renal parenchyma (P < 0.05). WT was isointense on T1-weighted (T1W) imaging, isointense or hypointense on T2-weighted (T2W) imaging. Tumor enhancement was less than normal renal cortex in all phases (P < 0.05). The number of tumor stages (grades I, II, III, and IV) was two, three, six, and five cases, respectively. Follow-up time was in the range of 19–123 months; six patients died within 3 years, six patients died within 5 years after the initial diagnosis, with the remaining patients still alive. Conclusion Adult WT tends to be a large tumor, isointense or hypointense on T2W imaging with enhancement less than normal renal parenchyma in all phases. The long-term follow-up results demonstrated the poor prognosis of the tumor.

Comparative study of CT appearances in mucinous tubular and spindle cell carcinoma and collecting duct carcinoma of the kidney.

OBJECTIVE To characterize the multidetector CT (MDCT) imaging characteristics of mucinous tubular and spindle cell carcinoma (MTSCC) and collecting duct carcinoma (CDC) of the kidney. METHODS 21 patients with MTSCC and 18 patients with CDC were studied retrospectively. MDCT was undertaken to investigate differences in tumour characteristics. RESULTS Five patients with MTSCC had calcifications as did nine patients with CDC (p = 0.108). In three patients with MTSCC and four patients with CDC, the tumours had a clear boundary (p = 0.682). No patient with MTSCC had retroperitoneal lymph node metastasis as did five patients with CDC (p = 0.015). 16 patients with MTSCC showed homogeneous enhancement, whereas 11 patients with CDC showed heterogeneous enhancement (p = 0.025). The attenuation value of CDC tumours was greater than that of MTSCC and normal renal parenchyma on an unenhanced CT (p = 0.027). MTSCC and CDC tumour enhancement was less than the normal renal cortex and medulla in all phases (p < 0.001). Tumour enhancement was greater for CDC than that for MTSCC in all phases (p = 0.011, p = 0.006 and p = 0.052). CONCLUSION Unenhanced and dynamic MDCT may aid in diagnosis and differentiation of MTSCC and CDC of the kidney. ADVANCES IN KNOWLEDGE This is the first series evaluating the imaging findings of MTSCC and CDC of which we are aware, and identification of such findings may improve diagnosis of these two rare tumours.

Multidetector CT imaging features of invasive renal parenchyma urothelial carcinoma.

OBJECTIVE To characterize the multidetector CT imaging features of invasive renal parenchyma urothelial carcinoma (IRPUC). METHODS 29 patients with IRPUC were retrospectively evaluated. Tumour location, density, cystic or solid appearance, calcification, capsule sign, enhancement pattern and metastases were assessed. RESULTS IRPUC involved the right kidney in 82.7% of patients. Medullary involvement was observed in 93.1% of patients. In 89.6% of patients, the reniform contour of the kidney was preserved. Tumours showed an infiltrative appearance (100%) with a poorly defined margin (100%), but an expansile component was also present (20.7%). Linear calcification was present (20.7%). Evidence of intra-abdominal metastatic disease (in 37.9% of cases) and regional lymphadenopathy (in 27.5% of cases) was present. Tumour attenuation was less or equal compared with the renal cortex or medulla on unenhanced CT (p-value> 0.05), after i.v. contrast administration; 100% were of homogeneous low attenuation compared with the normal renal cortex and medulla (p-value< 0.05). CONCLUSION IRPUC tends to be more prevalent in the right kidney, poorly defined margin, medullary involvement, with homogeneous enhancement less than the cortex and medulla in all phases. ADVANCES IN KNOWLEDGE IRPUC was more prevalent in the right kidney. IRPUC enhancement was less than that of the cortex and medulla on all phases. IRPUC showed poorly defined margin with medullary involvement and preserved reniform contour.

A Typical Angiosarcoma of the Posterior Mediastinum: One Case Reportand Review of the Literature

Angiosarcoma of the posterior mediastinum is a rare neoplasm of soft tissues and its location in the mediastinum is extremely uncommon. According to the papers of other cases reported on angiosarcoma in mediastinum, invasive biological behavior exist, such as ill-defined margin, heterogeneous density and local involvement of lung and ribs or vertebra. This case showed a well-defined, homogeneous mass. So, confusion is possible with other benign tumor in mediastinum.

WITHDRAWN: Comparative study of CT appearances in renal carcinoma associated with Xp11.2 translocation/TFE gene fusion and papillary renal cell carcinoma.

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