Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells showing intraductal growth and intratumoral hemorrhage: MRI features.

We report a case of undifferentiated carcinoma of the pancreas with osteoclast-like giant cells ocalized within the main pancreatic duct (MPD). A 61-year-old woman was referred to our hospital for evaluation of dilatation of the MPD that was detected on screening sonogram. Preoperative MR imaging revealed a small hypervascular tumor within the dilated MPD, showing high signal on R2* map and signal reduction on in-phase as compared to out-of-phase. R2* hyperintensity and in-phase signal reduction may be a characteristic feature of undifferentiated carcinoma of the pancreas with osteoclast-like giant cells, which indicates intratumoral hemorrhage even if they are small.