CT diagnosis for metastasis of clear cell renal cell carcinoma to the pancreas: Three case reports.

Rationale: Clear cell renal cell carcinoma (CCRCC) metastasis to pancreas is clinically rare. Misdiagnosis for these cases is frequently due to the low incidence, lack of specific clinical symptoms, and laboratory results.

Patient Concerns: Three female patients aged 47 years, 69 years, and 76 years, respectively, were admitted to hospital for routine examination after resection of clear cell carcinoma of kidney for 69 months, 57 months, and 123 months, respectively. All 3 cases had no specific clinical symptoms. Routine laboratory tests and common tumor markers including CEA, AFP, CA19-9, and CA125 showed no obvious abnormality.

Diagnosis: All 3 cases were finally diagnosed with CCRCC metastasis to pancreas on the basis of CT and pathological findings. On unenhanced CT, foci of the pancreas showed single or multiple nodules or masses with mildly low or equal density and obscure boundary. On enhanced CT, the enhanced mode of foci was similar to CCRCC and showed "fast in fast out." The main body was confined in the pancreas. The peripheral structure was clear relatively. Obstruction of common bile duct, main pancreatic duct, and local infringement of foci cannot be seen. Additional metastases of right adrenal gland can be seen in one case.

Interventions: All 3 cases underwent CT examination and surgical treatment, with complete removal of metastatic tumors.

Outcomes: All 3 cases underwent surgical treatment successfully, and recovered successfully after operation.

Lessons: The manifestations of pancreatic metastases from CCRCC on CT show certain characteristics, which may be useful to assess the histological features of pancreatic metastases from CCRCC and facilitate the preoperative diagnosis.