Umbilical metastasis as primary manifestation of cancer: a small series and review of the literature.

Umbilical metastasis is a rare manifestation of intra-abdominal cancer. It appears either as the first sign of a primary malignancy or as metastatic site of an already diagnosed cancer, representing an ominous prognostic finding. We report three cases of umbilical metastasis as the first sign of an underlying malignancy. Hypotheses about pathophysiology of umbilical metastasis are based on the embryological origin of the umbilicus and its residual communication with systematic, portal and lymphatic circulation.