Tumors and Tumorlike Conditions of the Anal Canal and Perianal Region: MR Imaging Findings.

Tumors and tumorlike conditions of the anus and perianal region originate from the anal canal and anal margin or result from direct extension of tumors from adjacent organs. The anatomy of the anal canal is complex, and its different histologic characteristics can lead to diverse pathologic conditions. The anal canal extends from the anorectal junction to the anal verge. The World Health Organization classification of anal canal tumors includes (a) anal intraepithelial neoplasia, the precursor of squamous cell carcinoma (SCC), and (b) invasive tumors. Invasive tumors are further classified on the basis of cell type as epithelial tumors (SCC, adenocarcinoma, mucinous adenocarcinoma, small cell carcinoma, and undifferentiated carcinoma), nonepithelial tumors, carcinoid tumors, melanoma, and secondary tumors (direct spread from rectal, cervical, or prostate carcinoma). The anal margin, or perianal skin, lies outside the anal verge and encompasses a radius of 5 cm from the anal verge. Tumors in the anal margin are classified according to the World Health Organization classification of skin tumors. Anal margin tumors include SCC, anal intraepithelial neoplasia, also known as Bowen disease, adenocarcinoma and its precursor Paget disease, basal cell carcinoma, and verrucous carcinoma (Buschke-Löwenstein tumor), which is a rare variant of SCC. Imaging plays an important role in the evaluation, staging, and follow-up of patients with anal and perianal tumors. However, because of the overlap in imaging features among these diverse entities, a definitive diagnosis is best established at histopathologic examination. Nevertheless, familiarity with the pathogenesis, imaging features, and treatment of these tumors can aid radiologic diagnosis and guide appropriate patient treatment. (©)RSNA, 2016.

Selective nonoperative management of abdominal gunshot wounds with isolated solid organ injury.

OBJECTIVE: To review selective nonoperative management (SNOM) of gunshot wound (GSW) patients with isolated abdominal solid organ injury. METHODS: Patients who sustained isolated solid organ injury secondary to GSW from 2003 to 2014 were studied. The use of SNOM over time was analyzed, and comparisons of initial SNOM and operative management (OM) groups were performed. RESULTS: Of 127 patients, 63 (50%) underwent SNOM. There were no significant differences between the early/late or SNOM/OM groups in demographics, physiologic presentation, or Injury Severity Score. SNOM increased from the early to late cohorts (31%-67%, p < 0.001), without any change in outcomes. SNOM patients had shorter hospital stays (5.8 vs. 10.0 days, p < 0.001), received fewer PRBCs (0.8 vs. 4 units, p < 0.001), and suffered fewer complications (13% vs. 28%, p < 0.05) than the OM group. CONCLUSION: An increase in SNOM vs. OM was associated with equivalent outcomes. Patients undergoing SNOM received fewer PRBCs and had shorter LOS.