68Ga-PSMA-avid synchronous rectal cancer: incidental malignancy in prostate cancer staging
Medical Review (Med. pregled), 2024, 60(1), 53-58.
M. Dyankova1,2, T. Stoeva1,2, Z. Dancheva1,2, P. Ilieva-Gabarska3, A. Klisarova1,2
1 Department of Diagnostic Imaging, Interventional Radiology and Radiation Therapy, Medical University “Prof. Dr. Paraskev Stoyanov” – Varna
2 Clinic of Nuclear Medicine and Metabolic Therapy, „Sv. Marina” University Hospital – Varna
3 Nuclear Medicine Laboratory in Medical Center „Sv. Marina” – Pleven
Abstract. PSMA has been revealed in tumor-related neovasculature cells of the endothelium in different nonprostatic cancerous tumors, along with colorectal malignancy and numerous subtypes of solid neoplasms. Our aim is to present an uncommon clinical case of occasional synchronous cancer with increased 68Ga-PSMA-uptake during primary staging for prostate cancer (PC). We show a case of a 71-year-old male, in whom a synchronous primary metastatic colorectal malignancy was revealed with a PSMA PET/CT scanning accomplished for staging of PC. Due to newly diagnosed prostate adenocarcinoma, the patient was referred for staging with 68Ga-PSMA PET/CT. PSMA-PET was accomplished and fused PET/CT images showed a focal intense PSMA activity related tо rectal tumor and lymph node in the pelvis with high radiotracer uptake, which were thereafter histologically confirmed as moderately dif- ferentiated synchronous colorectal adenocarcinoma with related metastatic regional lymph node in the pelvis and free intraperitoneal fluid. The present case demonstrates the importance of accurate interpretation and analysis of 68Ga-PSMA PET/CT scan results, as well as judgment for histological verification of incidentally identified tumor structures with increased PSMA-expression.
Key words: primary colorectal cancer, 68Ga-PSMA, adenocarcinoma
Address for correspondence: Marina Dyankova, MD, PhD, e-mail: Marina.Dyankova@mu-varna.bg