Primary melanoma of the umbilicus: report of a case and review of the relevant anatomy.

Background: Malignant melanoma presenting on the umbilicus is rare. Treatment of melanoma on the umbilicus is difficult because of the unusual anatomy of the umbilicus.

Objective: To present the case of a patient with a primary malignant melanoma of the umbilicus and to discuss treatment concerns that are relevant to the umbilical anatomy.

Methods: This is a case report as well as a review of the pertinent anatomy.

Results: The initial excision was read as having clear deep and lateral margins on histopathologic examination. Postoperative complications led to a re-excision down to and including the umbilical attachment to the peritoneum. The re-excision revealed residual primary cutaneous malignant melanoma in a remnant umbilical cyst.

Conclusion: When a malignant melanoma is located on the vertical sidewall or bottom of the umbilicus, one should consider surgical excision down to peritoneum, including the umbilical attachment to the peritoneum. Because this is beyond the scope of training for most dermatologic surgeons, it would be appropriate to refer these patients to a surgical oncologist or a plastic surgeon.