Collision metastasis of bladder and prostate carcinoma to a single pelvic lymph node.

Genitourinary organs are at greater risk for multiple primary malignant neoplasms because of the high incidence of these tumours as primaries among all other organs. We present a case of prostate and bladder carcinoma metastasized to a single pelvic lymph node, called a "collision" metastasis, in a patient with four primary tumours.