Sister Mary Joseph Nodules: A Case Report about a Rare Location of Skin Metastasis.

Umbilical skin metastases (or Sister Mary Joseph nodules) are rare. Their presence typically indicates the late manifestation of deep-seated abdominopelvic malignancy. They occur mainly in gynecological cancers, and gastrointestinal cancers in men. The most common histology is adenocarcinoma (∼75% of cases), but it can also rarely be squamous cell or undifferentiated carcinoma. These metastases can be present at diagnosis or appear at disease recurrence, and are associated with a very poor prognosis with an average survival of 11 months. We report the clinical case of a 58-year-old man with metastatic pancreatic adenocarcinoma and umbilical cutaneous metastasis after receiving first-line chemotherapy. The diagnosis was established upon liver biopsy in July 2019, after the patient presented with a complaint of transfixing abdominal pain. The first-line treatment consisted of six cycles of modified FOLFIRINOX chemotherapy. However, in November 2019, computed tomography (CT) scan showed disease progression. Second-line treatment with gemcitabine (Gemzar®) led to a 16% decrease in target lesions. During the fourth cycle, three periumbilical indurated nodules appeared. After six cycles, skin infiltration had increased, and the patient reported his abdominal pain had intensified. Reassessment by CT scan showed an increase in both hepatic and peritoneal disease progression. Third-line treatment with FOLFIRI, started on April 15, 2020, could not control the disease, leading to greater induration and subcutaneous infiltration, which were responsible for the increased pain and ultimate death. Umbilical skin metastases are rare, and they are associated with advanced metastatic disease and a very poor prognosis. Cases reporting Sister Mary Joseph nodules are needed to better understand the conditions and mechanisms of their appearance and dissemination.