An unusual case of an extensive post-injection retroperitoneal abscess in an intravenous drug user.

Retroperitoneal abscesses constitute an uncommon, complex, and life-threatening intra-abdominal infection. The insidious nature of the presentation, coupled with the presence of non-specific clinical symptoms, might result in misdiagnosis or delayed diagnosis, ultimately contributing to substantial morbidity and mortality. Herein we report a case of a 32-year-old intravenous drug user who presented to the emergency department complaining of high-grade fever, intense hiccough, and back pain due to retroperitoneal abscess formation after intravenous injection in the left femoral vein.

Primary peritoneal carcinoma: computed tomography and magnetic resonance findings.

OBJECTIVE: To present computed tomography (CT) and magnetic resonance imaging (MRI) findings of primary peritoneal carcinoma (PPC) at initial presentation (IP) and recurrent disease (RD). METHODS: We studied 15 consecutive female patients (age range, 47-83 years; mean, 66.2 years) with pathologically proven PPC who underwent CT and/or MRI between July 2000 and December 2005. Preoperative radiological evaluation and postoperative follow-up was done with CT and/or magnetic resonance studies. All CT and MRI studies were evaluated retrospectively, independently, and blindly by 2 radiologists for the imaging findings of PPC. RESULTS: The imaging findings were as follows: ascites, 2 of 2 at IP, 9 of 10 at RD; peritoneal thickening and enhancement, 1 of 2 at IP, 9 of 10 at RD; peritoneal nodules or bulky mass lesions, 1 of 2 at IP, 8 of 10 at RD; lymph node involvement, 1 of 2 at IP, 3 of 10 at RD; and distant metastases, 1 of 10 at RD. CONCLUSION: Ascites, peritoneal thickening and enhancement, and peritoneal nodules or bulky mass lesions were the most frequent findings of PPC. Recurrent disease revealed similar findings compared with the IP.

Pancreatic cancer: correlation of MR findings, clinical features, and tumor grade.

PURPOSE: To assess the frequency of occurrence of poorly-marginated and focally-defined pancreatic ductal adenocarcinoma by MRI and to determine whether these appearances correlate with clinical features and histopathological grade. MATERIALS AND METHODS: Institutional review board with waiver of informed consent was obtained for this HIPAA compliant study. A total of 33 patients (16 female, 17 male, mean age = 63.5 +/- 12.8, ranging from 41 to 80 years) with histopathologically-proven pancreatic ductal adenocarcinoma who underwent MR examination between August 2000 and February 2005 were retrospectively evaluated. Clinical data and histopathological tumoral grade were obtained from clinical charts; nine of 33 patients were excluded of the histopathological evaluation since their diagnosis was performed by fine needle aspiration biopsy and it was not possible to obtain the histopathological grade. Two radiologists reviewed all cases independently to identify whether cancers were poorly-marginated or focally-defined. Agreement between radiologists was assessed using the kappa coefficient. The overall correlation between imaging findings, clinical features, and histopathological grade was assessed with contingency tables using the Fisher's exact test. RESULTS: Of the 33 patients, nine (27.2%) were classified as poorly-marginated and 24 (72.8%) as focally-defined. Agreement between the two reviewers was excellent (k = 0.92, 95% confidence interval (CI) = 0.78-1.0). Poorly-marginated cancers exhibited well- to moderately-differentiated histopathology in 71.4% of cases, while focally-defined cancers had well- to moderately-differentiated histopathology in 17.6% of cases, P = 0.02. CONCLUSION: A poorly-marginated appearance of pancreatic ductal carcinoma on MRI is not uncommon. These cancers exhibited statistically significant moderate- to well-differentiated histopathology compared to focally-defined cancers.