Primary Melanoma of the Umbilicus: Report of a Case and Review of the Relevant Anatomy

Abstract

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.

Primary umbilical melanoma

“…level, and are much more common than primary malignant tumours. 2 Sister Mary Joseph's nodules are cutaneous metastases to the umbilicus, generally from intraabdominal malignant diseases. The source of the primary tumour may be from the gastrointestinal (35-65%) or genitourinary (12-35%) tract, haematological malignancies, lung and breast cancers (3-6%), or unknown (15-30%).…”

“…1,2 In particular, primary umbilical melanomas are extremely rare, with fewer than 12 cases reported in the literature. 1,2,[4][5][6][7] In a large series of 112 umbilical tumours, melanomas accounted for four of eight primary malignancies. 1 The mean age of these patients was 61 years (range 43-77 years) and the incidence was the same in both sexes.…”

“…1 Subsequently, primary umbilical melanoma has been reported in only single case reports. 2,[4][5][6][7] In approximately 50% of these cases melanomas developed in a pre-existing melanocytic naevus. 6 Therefore, an accurate surveillance of these umbilical naevi, including an excision of suspicious lesions, is recommended.…”

“…6 The presence of relevant vascular and embryological connections of the umbilicus with the peritoneum and other intra-abdominal visceral organs has important implications for the surgical approach to these patients. 2,6 It is known that the vestigial remnants of several embryonal structures, including the urachus, the vitelline artery, the vitello-intestinal duct, and the round ligament of the liver pass to the umbilicus. 2,3 Therefore, extension of a tumour developing in the umbilicus along these fibrous remnants has been suggested as a possible risk of incomplete excision and recurrence or metastatic spread.…”

“…2,3 Therefore, extension of a tumour developing in the umbilicus along these fibrous remnants has been suggested as a possible risk of incomplete excision and recurrence or metastatic spread. 2,6 Consequently, malignant umbilical tumours, including primary melanomas should be managed by wide excision of the entire umbilical structure, including its attachment to the underlying peritoneum. For the same reason, the role of SLNB in the management of umbilical tumours appears questionable.…”