A Retroperitoneal Foregut Duplication Cyst: A Case Report

Retroperitoneal foregut duplication cyst is an extremely rare congenital malformation. Pathologically, this lesion contains both gastric mucosa and respiratory type mucosa; radiologically, it is often challenging to differentiate it from the other cystic neoplasms that present a similar appearance. We report here on a case of retroperitoneal foregut duplication cyst that was lined by both gastric and pseudostratified ciliated columnar epithelium, and it was also accompanied by a pancreatic pseudocyst. Initially, it presented with peripancreatic and intrapancreatic cystic masses in an asymptomatic 30-year-old man, and this man has since undergone surgical resection.

Angiomyolipoma of the Perinephric Space: Case Report

Angiomyolipomas commonly originate from renal parenchyma but extremely rarely from perinephric space. We report a case of angiomyolipoma of the perinephric space confirmed by radical nephrectomy. A 13-year-old boy presented with left flank pain and abdominal distension, first experienced five months earlier. Ultrasonography and CT indicated that in the space surrounding the left kidney, a huge fat-containing mass with linear strands was present.

Unusual Perirenal Location of a Tailgut Cyst

The authors describe a case in which a tailgut cyst occurred at an unusual location in a 22-year-old woman referred for abdominal discomfort and urinary frequency. The left abdomen contained a palpable mass, found at imaging studies to be a homogeneous, unilocular and cystic, and anterior to the left kidney. After surgical excision, it was shown to be a tailgut cyst.

Retroperitoneal Castleman's Disease with Myxoid Degeneration: A Case Report

Castleman's disease is characterized by the presence of a rare benign tumor of lymphoid origin which usually arises in the mediastinum but rarely occurs in the retroperitoneum. In the radiology literature, the unenhanced CT appearance of the disease has been decribed as hypodense or isodense as compared to that of the liver, and as showing homogeneous contrast enhancement. In this case, CT revealed a well-circumscribed, homogeneous enhancing mass with an internal cystic portion, a finding different from those described in the literature. We report a case of retroperitoneal Castleman's disease in which there was unusual mucoid degeneration resulting in a large cystic component, and which has not been previously reported.

A Solitary Fibrous Tumor of the Retroperitoneum: CT Findings

The solitary fibrous tumor is a rare spindle cell neoplasm of mesodermal orgin. It usually arises in thepleura, though has recently been reported in the peritoneum, and at nonserosal sites; it is, however, extremelyrare in the retroperitonum. The authors describe one case of a solitary fibrous tumor occurred as a huge complexmass in the retroperitoneum of an adult. Preenhanced CT scans showed that the mass was sharply delineated fromsurrounding organs and that tumor density was the same as that of surrounding musculature. PeripheralCalcifications were noted, and postenhanced scans showed intense, gradual enhancement of solid portions of themass, with nonenhanced cystic portions. Although not specific, solitary fibrous tumors must be included in the differential diagnosis of a large retroperitoneal tumor of complex consistency and with internal calcification.

Calcifying Fibrous Pseudotumor of the Retroperitoneum: A Case Report

Calcifying Fibrous Pseudotumor of the Retroperi We report a case of calcifying fibrous pseudotumor in theretroperitoneum. This is a rare soft tissue mass le-sion with specific radiologic and pathologic findings, and itis the first reported case arising in the retroperi-toneum. The CT, MR and angiographic findings are described.

Retroperitoneal Fibrosis: Spectrum of Imaging Findings

Retroperitoneal fibrosis is a fibroproliferative process involving the retroperitoneum. It may be idiopathic or can be caused by methysergide ingestion, perianeurysmal inflammation, a leaking aneurysm, urinoma or irradiation. The symptoms and signs of retroperitoneal fibrosis are variable, and for diagnosis, imaging is therefore essential. The typical imaging finding is a fibrotic lesion in front of the lower vertebrae with ureteral obstruction. Atypical lesions, however, may occur in other parts of the retroperitoneum. The aim of this report is to describe the clinical features and various imaging findings of etroperitoneal fibrosis.

Idiopathic Retroperitoneal Fibrosis with Rectosigmoid Obstruction: Imaging Findings

Retroperitoneal fibrosis (RPF), although rare, can lead to significant intestinal obstruction. A case of RPF resulting in obstruction of the rectosigmoid colon is presented. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) revealed a characteristic fibrotic mass impinging on the rectosigmoid colon.

Radiologic Findings of Malignant Retroperitoneal Fibrosis

PURPOSE: To evaluate the radioloic findings of malignant retroperitoneal fibrosis. MATERIALS AND METHODS: Post-contrast CT (n=9) and urographic (n=7) findings of nine patients with malignant retroperitoneal fibrosis were retrospectively analyzed. Primary tumors were found to be advanced gastric cancer (n=6), early gastric cancer (n=1), breast cancer (n=1), and cervical cancer (n=1). We analyzed CT findings with regard to the site of soft tissue lesion, ureteral involvement, the presence or absence of hydronephrosis, and distant metastasis. The level and length of ureteral involvement, presence or abscence of ureteral stenosis, and ureteral displacement as seen on urography, were analyzed. RESULTS: On CT scans, enhanced soft tissue lesions (mass, 5 cases; plaque, 4 cases) encircling the abdominal aorta and IVC were noted in all cases. Thickening of the ureteral wall (n=8), hydronephrosis (n=9), and enlarged lymph node (n=5) were also seen. On urography, irregular stenosis and medial displacement of ureters from level L2 to S2 were noted in all cases. The length of ureteral involvement was 4-6.5cm. CONCLUSION: The common CT findings of malignant retroperitoneal fibrosis were enhanced soft tissue lesion encircling the abdominal aorta and IVC, hydronephrosis, and thickening of the ureteral wall. On urography, ureteral stenosis and medial displacement were seen.

CT Demonstration of the Extensive Extension of the Emphysematous Gangrene of the Lower Extremity Extending tothe Body: A Case Report

Emphysematous gangrene of the lower extremity in a diabetic patient due to minor trauma is being presented. The gas originating from the extremity extended along to fascial planes into the pelvic cavity, scrotal region, retroperitoneal space, and abdominal wall. CT demonstrated the pathways of upward extension of emphysematousgangrene. Anatomic pathways of the spread of the disease are insertions of the iliopsoas, piriformis and obturator internus muscles, and their fascial investments, and the endopelvic fascia. Anatomic pathways on CT and the roleof CT are discussed.

Solitary Fibrous Tumor in Retroperitoneum

The solitary fibrous tumor, of rare mesodermal origins, primarily affects the pleura and occasionally occursin the peritoneum and at nonserosal sites. Although this is a pathologically well established entity, it isfrequently confused radiologically and pathologically with other tumors of mesenchymal origin. We report one case of a solitary fibrous tumor in the retroperitoneum. The 15X10X7cm mass, lacated in the left perirenal space just above the left kidney, had relatively homogeneous consistency and was well-delineated from surrounding organs inCT and MR images. It showed intense, gradual, centripetal enhancement during dynamic scans, and partially unenhanced areas which matched the high signal intensity portions in T2 weighted MR images, pathologically correlated to myxoid degeneration. Although not specific, when a large, well-delineated mass of strong contrast enhancement with lack of massive necrosis is encountered, solitary fibrous tumor must be included in the differential diagnosis of a refroperitoneal soft tissue mass.