Painful penile erection as a manifestation of metastatic pancreatic ductal adenocarcinoma

BACKGROUND: Penile metastasis represents one of the rarest metastatic sites despite the organ's rich vascular network. Most reported cases originate from malignancies of the genitourinary tract, whereas metastasis from pancreatic ductal adenocarcinoma (PDAC) is exceedingly uncommon. Primary tumors responsible for penile metastases are typically located in the prostate or rectum and are frequently associated with disseminated disease and poor prognosis. CASE PRESENTATION: An 86-year-old man presenting with abdominal pain underwent distal pancreatectomy with regional lymphadenectomy for PDAC. Three months after surgery, computed tomography revealed multiple liver metastases, para-aortic lymph node involvement, and peritoneal dissemination. Subsequently, the patient developed penile pain and persistent erection. Physical examination revealed multiple whitish indurated nodules on the glans penis. Ultrasonography demonstrated a hypoechoic mass, and a penile biopsy confirmed metastatic adenocarcinoma consistent with the primary pancreatic lesion based on morphological features and KRT7/20 immunoprofiles. The patient's condition progressively deteriorated, and he died five months after surgery. CONCLUSION: Penile metastasis from PDAC is an extremely rare event and portends a dismal prognosis. Including our patient, only six cases have been documented to date. Awareness of this manifestation is important, as penile symptoms such as pain or persistent erection in patients with PDAC may indicate advanced systemic dissemination.