[A case of Sister Mary Joseph's nodule as a presenting sign of gastric cancer].

The cutaneous metastasis of a visceral malignancy to the umbilicus is known as "Sister Mary Joseph's nodule (SMJN)". It is considered to be a predictor of poor prognosis because it mostly occurs in advanced, metastasizing cancer. However, it is a very rare condition as an initial presenting sign of primary cancer. We recently encountered a 48-year-old man presented with an umbilical lump. The lesion was a firm, ill-delineated, painful nodule with regular surface in the umbilicus. Abdominal computed tomography showed a 2.2 cm sized, ill-defined, delayed enhancing mass at the periumbilical area accounting for umbilical nodule. Diffuse irregular thickening of peritoneum and diffuse wall thickening of stomach implied the diagnosis of gastric cancer. Esophagogastroduodenoscopy revealed diffuse nodular infiltrative lesion from cardia through body of the stomach, compatible with Bormann type 4 advanced gastric cancer. Later, histopathologic confirmation showed a presence of signet ring cell adenocarcinoma from biopsy specimens. We experienced a case presenting with an umbilical metastasis as the first sign of gastric adenocarcinoma. It is thought that direct extension of tumor through the peritoneum might be the route for umbilical metastasis. Careful examination of all umbilical lesions must be needed for the early diagnosis of internal malignancy.