[Uncommon manifestation of prostate cancer : Sister Mary Joseph's nodule]

We report on the case of an 81-year-old man suffering from prostate cancer for several years. In recent months, PSA levels increased, and ⁶⁸Ga-PSMA-PET-CT (PSMA: prostate-specific membrane antigen) imaging demonstrated suspicious lesions in the paravesical area and an umbilical tumor mass. Local excision was performed. Histologically, the tumor mass was diagnosed as metastasis of the prostate cancer, which is also designated as Sister Mary Joseph's nodule. Umbilical metastases of primary prostate cancer are extremely rare; however, they are of clinical importance since they are commonly associated with tumor progress and with a particularly poor prognosis.