F-18 FDG accumulation in mucinous cystic neoplasm of pancreas.

We report a case of mucinous cystic neoplasm which showed FDG accumulation in its cyst wall. MRI revealed that this tumor had repeated intracystic hemorrhage. Inhomogeneous FDG accumulation was found in the cyst wall. The epithelium was focally denuded and ovarian-like stroma with macrophage migration, which phagocytosed red blood cells, and fibrosis were recognized on histopathological examination. These histopathological findings suggested that FDG accumulates not in the monolayer epithelium but in ovarian-like stroma with macrophage migration and fibrosis. Macrophage migration and fibrosis were considered to have contributed to FDG accumulation in this mucinous cystic neoplasm.