Follicular Dendritic Cell Sarcoma of the Abdomen: the Imaging Findings

Follicular dendritic cell sarcoma is a rare neoplasm that originates from follicular dendritic cells in lymphoid follicles. This disease usually involves the lymph nodes, and especially the head and neck area. Rarely, extranodal sites may be affected, including tonsil, the oral cavity, liver, spleen and the gastrointestinal tract. We report here on the imaging findings of follicular dendritic cell sarcoma of the abdomen that involved the retroperitoneal lymph nodes and colon. It shows as a well-defined, enhancing homogenous mass with internal necrosis and regional lymphadenopathy.

Fibrolamellar Hepatocellular Carcinoma Mimicking Malignant Lymphoma: A Case Report

Fibrolamellar hepatocelluar carcinoma is a distinct clinicopathologic variant of hepatocellular carcinoma. We describe here the sonographic and CT findings of fibrolamellar hepatocellular carcinoma in a 17-year-old patient that mimicked hepatic malignant lymphoma due to the multiple small hypoattenuating nodules and extensive lymphadenopathy that we observed. We also include a review of the relevant literatures.

CT Findings of Small Bowel Metastases From Primary Lung Cancer

PURPOSE: To evaluate the CT findings of small bowel metastases from primary lung cancer. MATERIALS AND METHODS: Of the 1468 patients with primary lung cancer between 1990 and 2000, 13 patients who had metastasis to the small intestine were collected. Of these 13 patients, nine who underwent CT scan were included for analysis. The pathologic diagnoses of primary lung cancer in these nine patients were squamous cell carcinoma in six, adenocarcinoma in two, and large cell carcinoma in one. CT scans were analyzed with regard to the site and patterns (intraluminal mass/bowel wall thickening/bowel implants) of metastatic masses, and the presence or absence of complication such as intussusception, obstruction, or perforation of the small bowel. The medical records of the patients were also reviewed retrospectively for evaluation of presenting abdominal symptom and time interval of metastases from initial diagnosis of lung cancer. RESULTS: Metastatic lesions were distributed throughout the small intestine: the duodenum in five, the jejunum in four, the ileum in six, and both jejunum and ileum in one patient. The size of metastatic masses of small bowel ranged from 1.3 cm to 5.0 cm (mean size, 2.6 cm) On CT, the small bowel was involved with intraluminal masses (mean size, 3.4 cm) in eight patients, diffuse wall thickening (mean thickness, 1.6 cm) in five, and bowel implants (mean size, 2.2 cm) in two. Complications occurred in seven patients, including intussusceptions without obstruction in two patients and with obstruction in two, obstruction without intussusceptions in two, and bowel perforation in one. Of 9 patients, 6 had at least one symptom referable to the small bowel including abdominal pain in 4, anemia in 3, vomiting in 1, and jaundice in 1. Lung cancer and small bowel lesions were detected simultaneously in four patients and the time interval of metastases from initial diagnosis of lung cancer ranged from 10 days to 30 months (median interval, 54 days) in 5 patients. CONCLUSION: CT helps in defining the extent and pattern of small bowel metastases as well as in demonstrating their complication.

Desmoplastic Small Round Cell Tumor: Radiologic Findings

PURPOSE: To evaluate the radiologic findings of intra-abdominal DSRCT. MATERIALS AND METHODS: We reviewed sixcases of pathologically proven DSRCT of the abdomen. Five of these patients were men and one was a woman ; theiraverage age was 26.8 years. We retrospectively analyzed CT(n=6) and MRI(n=4). RESULTS: In all patients, largerelatively well defined lobulated mass was seen;this arose from the peritoneal surface, and its average size was12.6(range, 10-18)cm. After the administration of contrast material, the masses showed inhomogeneous enhancement,and in addition, the following features were seen: irregular internal septations (n=5); necrosis (n=3); andamorphous calcification (n=4). Various associated findings such as ascites (n=4) and multiple para-aortic lymphnode enlargement (n=4) were present; omental cake (n=5), liver metastasis (n=1), cervical lymphadenopathy (n=1),hydronephrosis (n=1), small bowel obstruction (n=1), scrotal swelling (n=1) and collateral vessels by encasedaorta and renal vein (n=1) were also seen. CONCLUSION: In young male patients with a large heterogeneous enhaneedcalcified abdominopelvic mass and findings of carcinomatosis on both CT and MR images, DSRCT should be inelvded inthe differential diagnosis.

CT-Guided Celiac Plexus Block with Absolute Alcohol: the Anterior Approach

PURPOSE: To evaluate the safety and efficacy of CT-guided celiac plexus block (CPB) using an anterior approach, and to determine the role of CT in this procedure. MATERIALS AND METHODS: CPB was attempted in 15 patients (10 men and 5 women; mean age, 62.3 years) with intractable upper abdominal pain due to terminal malignancy of the pancreas, liver, bowel, and kidney. To permit an anterior approach, patients lied supine on the CT scan table during the procedure. One or two 21-guage needles were placed just anterior to the diaphragmatic crus at or between the levels of the celiac and superior mesenteric arteries and 10-40 ml of 99.9% alcohol was injected. Pain relief following the procedure was assessed and pain was graded on a visual analogue scale (VAS) from 0 to 10. RESULTS: There were no technical failures and no neurologic or hemorrhagic complications. Abdominal pain during alcohol injection occurred in all patients, and transient hypotension in three. One patient with recurrent cancer of the pancreatic head died of sepsis five days after the procedure; the cause of sepsis was difficult to determine, but there was thought to be a biliary source of infection. Two days after block, 13 of 15 procedures (86.7%) had produced at least partial pain relief ; in 12 patients, relief was good. With CT guidance, more directed positioning of the needle is possible, allowing alcohol to be deposited in specific ganglion areas. CONCLUSION: CT-guided celiac plexus block using an anterior approach was an easy and effective way of reducing intractable upper abdominal pain due to terminal malignancies. CT guidance allowed precise needle placement and a safer procedure.

Abdominal Burkitt Lymphoma in Children: CT Finding

PURPOSE: To evaluate the CT findings of Burkitt's lymphoma involving the abdomen in children. MATERIALS AND METHODS: We retrospectively analyzed the abdominal CT of ten children who presented with abdominal symptom. Theywere confirmed by operation in two cases and by fine needle aspiration biopsy in eight to be suffering from Burkitt's lymphoma. We also abdominal ultrasonography(USG) (n=10) and carried out small bowel follow-through examination(SBS) (n=5). Analyses focused on features of the abdominal mass : bowel wall thickening, ascites, lymphadenopathy, and the involvement of intra-abdominal solid organ. RESULTS: Abdominal CT at the time ofpresentation showed a huge conglomerated mass encasing segments of small bowel and also peripherally displacingbowel loops (n=9), bowel wall thickening (n=10), and ascites (n=10). In three of these cases, we were able to see tumor necrosis and cavity formation. Extensive infiltration into mesenteric fat and obliteration of tissue planemade it impossible to identify on CT the margin of the tumor and the presence of mesenteric lymphadenopathy. Infour patients, sonography showed enlarged mesenteric lymph nodes(15-20mm), and in three, retroperitoneal lymphnodes(5mm, 10mm, 12mm in long dimension) were detected on CT and USG. CONCLUSION: Abdominal CT can reveal the characteristic imaging features of Burkitt's lymphoma in children. These are a huge conglomerate mass with or without cavity formation, that encases the small bowel and infiltrates the mesentery, ascites, and the relatively spared retroperitoneal lymph nodes.

Radiological Findings of Primary Abdominal Malignant Fibrous Histiocytoma: Emphasis on CT Findings

PURPOSE: To evaluate the radiological findings of abdominal malignant fibrous histiocytomas. MATERIALS AND METHODS: We retrospectively reviewed the radiological findings of 13 masses in seven patients including two patients with multiple masses. The masses were located at the mesentery and omentum in three patients and at theretroperitoneum in four. Gastrointestinal examination using barium was performed in four patients, ultrasonographyin five and computed tomography in all. RESULTS: The average diameter of masses was 7.8cm(range : 1-20cm); plain abdominal films revealed soft tissue masses in all patients. Three of four barium studies demonstrated only displacement of bowel loops and the other showed findings of submucosal tumor. Eight of 11 masses were detected on ultrasonography and all were round or lobulated and had well defined margins. Four of these masses were greater than 8cm in diameter and showed homogeneous echogenicity with central hypo or anechoic area ; the remaining wereless than 8cm and showed relatively homogeneous echogenicity. On computed tomography, all 13 masses were seen as highly enhanced and well circumscribed. Seven were greater than 5cm in diameter and had internal low-densityareas. Peritumoral vessel-like structures were seen in eight masses and on plain abdominal radiograph and computed tomogram, calcification was seen in one patient. In no patient was combined retroperitoneal or intraperitoneal lymphadenopathy noted. CONCLUSION: Abdominal malignant fibrous histiocytomas are well-circumscribed, round orlobulated bulky masses with frequent necrosis and occasional calcification. Characteristically, there is nocombined lymphadenopathy and multiple masses are a rare manifestation. These findings may be helpful in the diagnosis of malignant fibrous histiocytoma.