A Case of Multiple Pancreatic Acinar Cell Carcinoma with a Clinical Course Suggesting a Possibility of Multi-centric Carcinogenesis

Abstract

A 79-year-old man presented with abdominal pain and was found to have a 20 × 13 mm tumor in the pancreas head, a 38 × 22 mm tumor in the pancreas tail, and a 9-mm diameter nodule in the left adrenal gland on abdominal CT. He was diagnosed with pancreatic acinar cell carcinoma associated with adrenal metastasis and was referred to our hospital. We introduced gemcitabine and nab-paclitaxel combination therapy, but it had to be withdrawn due to adverse events. Then the therapy was replaced with S-1, but it was also interrupted due to drug eruption. Evaluation after chemotherapy revealed partially effective for the pancreas head lesion and stable for the pancreas tail lesion. Reevaluation of the left adrenal lesion with ultrasonic endoscopic needle aspiration cytology denied adrenal metastasis. Accordingly, we determined that radical resection might be possible and total pancreatectomy was performed. The histopathological diagnosis of the two pancreatic lesions was pancreatic acinar cell carcinoma.

Pancreatic acinar cell carcinoma is a rare form of pancreatic neoplasm, especially multiply occurred one, which has been reported in only one case so far. In this case, imaging changes and pathological features after chemotherapy differed from the pancreas head to the body lesions, leading to our consideration that tumors with different biological characteristics might arise from multicentric carcinogenesis.