Role of computed tomography in the staging of primary melanoma

To evaluate the role of body computed tomography (CT) for the staging of patients with early melanoma.

A total of 151 new patients with American Joint Committee (AJC) clinical stage I, II, and III melanoma who received a CT scan of at least the chest and abdomen are the subject of this study. CT scans considered suspicious for metastases were reviewed again by one of the investigators (A.McB.C.).

Of 151 patients, 63 had AJC clinical stage I, 61 stage II, and 23 stage III disease. In addition, one patient each had primary melanoma of the anal canal, esophagus, or vulva. Twenty-nine (19%) of 151 patients had a CT scan that was considered suspicious for metastases. The most common radiologic findings were single hepatic, and single or multiple pulmonary nodules. Of these 29 patients with suspicious scans, 24 subsequently proved to have benign processes by biopsy or follow-up studies, three had second primary tumors (well-differentiated lymphocytic lymphoma, Hodgkin's disease, and renal cell carcinoma), and only two were found to have metastatic melanoma. Of these two patients, one had regional nodal disease (unsuspected on physical examination) and one had distant nodal metastases.

Body CT is not a useful imaging study in the detection of occult metastases in patients with primary melanoma. Although body CT commonly shows suspicious radiologic abnormalities in patients with early melanoma, these abnormalities most likely represent benign processes or a second primary tumor, rather than metastatic melanoma. The value of body CT in patients who present with nodal metastases needs further study.