Original Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Radiol. Feb 28, 2013; 5(2): 25-32
Published online Feb 28, 2013. doi: 10.4329/wjr.v5.i2.25
Melanoma metastases in the abdomen and pelvis: Frequency and patterns of spread
Andrew T Trout, Risa S Rabinowitz, Joel F Platt, Khaled M Elsayes
Andrew T Trout, Joel F Platt, Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States
Risa S Rabinowitz, University of Michigan, Ann Arbor, MI 48109, United States
Khaled M Elsayes, Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Trout AT, Elsayes KM and Platt JF designed the research and wrote the paper; Trout AT and Rabinowitz RS performed the research; Trout AT analyzed the data.
Correspondence to: Andrew T Trout, MD, Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109, United States. trout.andrew@gmail.com
Telephone: +513-636-4504 Fax: + 513-636-8145
Received: June 4, 2012
Revised: August 30, 2012
Accepted: January 31, 2013
Published online: February 28, 2013
Abstract

AIM: To investigate the frequency, typical and atypical locations and patterns of melanoma metastases identifiable by computed tomography (CT) in the abdomen and pelvis.

METHODS: We performed a retrospective review of index CT examinations of the abdomen and pelvis in patients with melanoma and recorded all findings suggestive of metastatic disease.

RESULTS: Metastases were present on 36% (181/508) of the index examinations and most commonly involved the liver (47%) and pelvic lymph nodes (27%). Lower extremity primaries had the highest rate of metastasis (52%). Ocular and head and neck melanomas have a predilection to metastasize to the liver (hepatic involvement in 70% and 63%, respectively, of patients with metastatic disease) and metastases from lower extremity primaries most commonly involve pelvic lymph nodes (54% of patients with metastatic disease). Metastases to atypical locations were present in 14% of patients and most commonly occurred in the subcutaneous tissue and spleen. Primary tumors of the lower extremity, back and head and neck were most commonly associated with atypical metastases. Pelvic metastases are more common with lower extremity primaries (accounting for 70% of cases with pelvic metastases) but 5% of patients with supraumbilical primaries also had pelvic metastases.

CONCLUSION: The distribution of metastatic melanoma in the abdomen and pelvis that we have defined should help guide the interpretation of CT exams in these patients.

Keywords: Melanoma; Metastases; Computed tomography; Abdomen; Pelvis