Sister Mary Joseph's nodule: Three case reports

BACKGROUND An umbilical metastatic lesion is called 'Sister Mary Joseph's nodule'. It is an uncommon clinical or radiographic finding, and it is rare as the first sign of a malignant disease. CASE PRESENTATION We report three cases of Sister Mary Joseph's nodule. In the three cases presented, the primary tumor was an adenocarcinona of the sigmoid colon, a carcinoma of the bladder, and an adenocarcinoma of the gallbladder, respectively. CONCLUSION The differential diagnosis of an umbilical lesion should always include metastatic disease apart from benign lesions and primary neoplasms.