Clinical potential of an antitumor drug sensitivity test and diffusion-weighted MRI in a patient with a recurrent solid pseudopapillary tumor of the pancreas.

A solid pseudopapillary tumor (SPT) of the pancreas is a rare type of pancreatic neoplasm found predominantly in young women. SPTs typically behave as though benign; however, in some cases they also have malignant potential. We encountered a rare case of a recurrent SPT that developed 4 years after the initial surgery in an elderly male patient. Abdominal computed tomography (CT) revealed that the 61-year-old patient had four intra-abdominal masses, suggesting a recurrence of SPT. The patient had a history of distal pancreatectomy due to SPT in the pancreatic tail 4 years previously. These tumors showed positive signals on diffusion-weighted magnetic resonance imaging (MRI), and were treated successfully by aggressive surgical resection. Microscopic diagnosis was compatible with recurrent tumors of SPT. A chemosensitivity test, the collagen gel droplet-embedded culture drug sensitivity test (CD-DST), showed that the resected tumors were sensitive to several antitumor drugs. We suggest that the CD-DST may be used to indicate promising antitumor agents for treating SPTs with malignant tendencies. In addition, a diffusion-weighted MRI can be useful for accurately visualizing SPTs of the pancreas.