Late Ga PSMA-positive Pancreatic Metastasis From Renal Cell Carcinoma in a Patient with Metastatic Prostate Cancer: A Mission Impossible.

We present the case of a patient with newly diagnosed high-risk prostate cancer. The patient underwent nephrectomy for renal cell carcinoma (RCC) in 2009. The prostate-specific membrane antigen (PSMA) scan revealed a primary tumor with seminal vessel involvement, PSMA-positive regional lymph nodes, several nodular lung lesions with mild PSMA uptake, PSMA-positive mediastinal lymph nodes, and a PSMA-positive mass in the pancreatic head. Ultrasound-guided biopsy was performed for the pancreatic lesions revealing metastasis from a RCC. Simultaneous treatment for prostate cancer and metastatic RCC was initiated. To separate metastatic sites for both primaries, we attempted to use fluorodeoxyglucose positron emission tomography/computed tomography, which was moderately positive for the pancreatic mass but not for the other locations. RCC is a Ga PSMA-positive tumor; the synchronous combination of RCC with prostate cancer can be confusing and requires more complex clinical interpretation.