[Carcinoma of Unknown Primary Associated with a Sister Mary Joseph's Nodule--A Case Report].

A 72-year old woman visited our hospital complaining of an umbilical mass and a foul smell from the umbilical region. During the evaluation, a massive immobile tumor was palpated in the center of the lower abdomen in addition to an umbilical mass with necrosis. Computed tomography (CT) revealed a massive ovarian tumor accompanied by an umbilical tumor and cyst with peritoneal dissemination, metastases in the liver and spleen and a urachal tumor. There were no symptoms or imaging findings of gastrointestinal obstruction. While searching for the primary focus, it was determined that the ovarian tumor was not of ovarian origin. Under these circumstances, colonoscopy was the only remaining diagnostic modality. However, evaluation of the large intestine was impossible due to compression by the tumor, and diverticulosis of the sigmoid colon did not allow smooth insertion of the colonoscope. Therefore, an excisional biopsy of the umbilical tumor was performed. The most likely diagnoses based on the histopathological findings were colorectal cancer and urachal cancer. Therefore , mFOLFOX6 was selected for chemotherapy because it has been reported to be effective against both urachal and colorectal cancer. At the time of writing, good tumor control had been achieved in the lesions evaluated. Cases of Sister Mary Joseph's nodule have sporadically been reported. The most common primary foci for peritoneal metastases are the stomach, pancreas and ovary. However, in the present case, these sites were ruled out and the primary focus remained unidentified, making it difficult to select appropriate treatment. We present this case with a discussion of the literature.