Metastatic vs primary malignant neoplasms affecting the umbilicus: clinicopathologic features of 77 tumors.

Periumbilical skin is unique due to its proximity to intra-abdominal and pelvic structures. In addition to primary skin malignancies, it is a site often involved with metastatic disease. We reviewed the clinical and pathologic features of 77 umbilical malignancies occurring at our institution since 1988. Seventy-seven patients were identified (female/male ratio, 4.1:1.0) with the average age for women being 63 years and 55 years for men. Eighty-eight percent of malignancies originated outside the umbilicus and 12% were primary skin tumors. Fifty-eight (85%) patients with metastatic tumors had umbilical involvement from a known primary vs 10 (15%) with unknown primaries. Nine patients with metastatic tumors to the umbilicus would present with solitary umbilical involvement. Of these patients, 56% would not have a primary site assigned to their metastatic disease. In women, the 3 most common primary sites were the ovary, endometrium, and pancreatobiliary tree, whereas for men, it was the genitourinary tract, pancreatobiliary tree, and the gastrointestinal tract. Of the primary umbilical malignancies, 44% of patients were male and 56% female. Malignant melanoma was the most common primary umbilical malignancy. In summary, women are more likely than men to have malignant tumors affecting the umbilicus. Overall, the most likely primary site of a metastatic tumor to the umbilicus is the genitourinary tract. Rarely, patients present with metastatic tumors to the umbilicus, and most of these patients will not have a primary site of tumor origin assigned.