Primary Orbital Eccrine Porocarcinoma: Serial [¹⁸F]FDG PET/CT Demonstration of Rapid Disease Progression

Primary orbital eccrine porocarcinoma is an exceptionally rare and aggressive malignancy. We present the case of a 67-y-old man with primary orbital eccrine porocarcinoma who underwent initial staging and postoperative restaging with [¹⁸F]FDG PET/CT. Initial imaging revealed an intensely hypermetabolic orbital mass with regional and contralateral cervical lymph node metastases. Four months after radical surgery, restaging PET/CT demonstrated rapid systemic progression involving multiple organs and skeletal structures. This case highlights the value of serial [¹⁸F]FDG PET/CT for comprehensive assessment of disease extent and rapid metastatic progression in this rare malignancy.