Sister Mary Joseph nodule

Sister Mary Joseph nodule refers to a subcutaneous metastatic deposit at the umbilicus arising from a primary malignancy elsewhere, most frequently gastrointestinal (stomach, colon, pancreas) or gynecologic (ovary) cancers. The nodule results from tumor spread via direct peritoneal extension, lymphatic dissemination (through the ligamentum teres or median umbilical ligament), or hematogenous spread, given the umbilicus's rich vascular and lymphatic connections to abdominal viscera. Clinically, it presents as a firm, sometimes ulcerated or friable nodule that may be tender, associated with discharge, and often noted incidentally on physical exam. Its presence indicates advanced, usually stage IV disease with a poor prognosis (median survival often less than a year). Diagnosis is confirmed via biopsy showing adenocarcinoma or other tumor histology matching the primary source, followed by imaging (CT abdomen/pelvis, endoscopy) to identify the primary tumor. The eponym honors Sister Mary Joseph Dempster, a surgical assistant to Dr. William Mayo at the Mayo Clinic, who first noted the association between this umbilical finding and intra-abdominal malignancy. On boards, this term is tested as a classic physical exam sign linking a seemingly benign skin/umbilical finding to underlying visceral cancer, emphasizing the need for thorough abdominal malignancy workup when an umbilical nodule is found.