Mesenchymal neoplasms of the kidney in adults cover a wide spectrum with characteristic ontogeny and histologic findings and variable biologic profiles and imaging findings. Benign mesenchymal renal tumors include angiomyolipoma, leiomyoma, hemangioma, lymphangioma, juxtaglomerular cell tumor, renomedullary interstitial cell tumor (medullary fibroma), lipoma, solitary fibrous tumor, and schwannoma. Malignant renal tumors of mesenchymal origin include leiomyosarcoma, rhabdomyosarcoma, angiosarcoma, osteosarcoma, synovial sarcoma, fibrosarcoma, malignant fibrous histiocytoma, and solitary fibrous tumor. Cross-sectional imaging findings for mesenchymal renal tumors in adults are varied. Although angiomyolipomas and lipomas show macroscopic fat, lymphangiomas are cystic in appearance. Renal hemangioma may show phleboliths and a characteristic enhancement pattern. Leiomyoma typically arises from the capsule and causes buckling of the renal cortex. Although osteosarcoma may demonstrate characteristic dense ossification, most renal sarcomas demonstrate imaging features that are indistinguishable from the more common renal cell carcinoma. Although some renal mesenchymal tumors have typical imaging findings, biopsy is warranted to establish a definitive diagnosis. Awareness of the various mesenchymal renal tumors and familiarity with their imaging findings permit optimal patient management.

Borderline tumors are considered to be precursors of low-grade ovarian cancers. Accurate diagnosis and staging facilitate optimal patient management particularly in patients desiring to preserve fertility.

Objective:Emphysematous cholecystitis is a severe form of acute cholecystitis and can be rapidly fatal. We present the imaging features of nine patients with proven emphysematous cholecystitis.

Although large bowel obstruction (LBO) is less common than small bowel obstruction, it is associated with high morbidity and mortality due to delayed diagnosis and/or treatment. Plain radiographs are sufficient to diagnose LBO in a majority of patients. However, further evaluation with multidetector computed tomography (MDCT) has become the standard of care to identify the site, severity, and etiology of obstruction. In this comprehensive review, we illustrate the various causes of LBO emphasizing the role of MDCT in the initial diagnosis and detection of complications along with the tips to differentiate from disease which can mimic LBO.