Partially intraosseous schwannoma of the distal humerus with increased enhancement after biopsy: Radiologic-pathologic correlation.

Intraosseous schwannomas are rare benign tumors that most often occur at the mandible or sacrum. We present an unusual case of a bilobed schwannoma of the distal humerus with both intraosseous and extraosseous components. The extraosseous component was non-enhancing on initial MRI and enhanced on a subsequent MRI obtained after biopsy. We hypothesize that this change was attributable to decreased intra-tumoral pressure secondary to biopsy-related disruption of the tumor capsule.

Factors Affecting Adherence to Recommendations for Additional Imaging of Incidental Findings in Radiology Reports.

OBJECTIVE: To determine the rate at which recommendations for additional imaging (RAIs) of incidental findings on CT are adhered to at a tertiary-care medical center and what factors influence adherence. METHODS: We used a radiology clinical informatics tool (mPower, Nuance Communications Inc, Burlington, Massachusetts) to identify RAIs in reports from all CT examinations performed at a tertiary-care medical center during a 6-month period. For those studies in which the RAI was for incidental findings, we reviewed the patients' charts to determine if there was appropriate follow-up of the lesion in question. RESULTS: The overall rate of adherence to RAIs was 39.1%, and in patients with a same-institution primary care provider (PCP), 56.8% (P < .0001). Adherence was higher in studies ordered in the outpatient setting (P < .0001) and in patients with a same-institution PCP (P < .0001). Among patients with a same-institution PCP, adherence was highest for outpatients (66.7%), followed by patients seen in the emergency department (46.0%) and inpatients (36.0%). Among outpatients, adherence was highest with PCPs (67%) followed by internal medicine subspecialties (50%) and surgery (38%). DISCUSSION: The rate of adherence to recommendations for additional imaging of incidental findings was 39.1% in this study and higher for patients with a same-institution PCP, studies ordered in the outpatient setting, and in studies ordered by PCPs.

Prevalence of Solid Tumors in Incidentally Detected Homogeneous Renal Masses Measuring > 20 HU on Portal Venous Phase CT.

OBJECTIVE: The purpose of this study was to determine the prevalence of solid tumors in incidental homogeneous renal masses with attenuation greater than 20 HU on portal venous phase CT images. MATERIALS AND METHODS: In this retrospective study, the records of patients with incidental indeterminate (> 20 HU) homogeneous renal masses on portal venous phase CT scans from September 11, 2007, through March 18, 2017, were identified. Adult patients were included if they had undergone follow-up ultrasound, contrast-enhanced MRI, multiphase contrast-enhanced CT, or pathologic analysis alone to confirm the solid or cystic nature of the lesion. A single ROI was placed in the center of the mass, and lesions were characterized as ≥ 50% exophytic, < 50% exophytic, or entirely surrounded by renal parenchyma. RESULTS: There were 322 masses in 267 patients. The mean lesion size was 16.6 (SD, 9.8) mm (range, 9-45 mm). Lesions were ≥ 50% exophytic in 92 cases, < 50% exophytic in 111 cases, and completely surrounded by renal parenchyma in 119 cases. All nonsolid lesions were characterized as benign cysts. The numbers of solid lesions per total number of lesions in each attenuation group were: 20-30 HU (0/140), 30-40 HU (0/67), 40-50 HU (1/38), 50-60 HU (3/24), 60-70 HU (5/17), 70-80 HU (5/17), and > 80 HU (8/19). All 207 lesions in the 20- to 40-HU range were benign cysts with no solid lesions (0%; 95% CI, 0.0-1.4%). CONCLUSION: Small homogeneous renal masses measuring 20-40 HU on portal venous phase CT images are highly likely to be benign cysts.