Elevated F-18 FDG uptake in plasmacyte-rich chronic maxillary sinusitis.

Abstract

Presented is a patient who had a benign lesion with elevated F-18 FDG uptake. A 58-year-old man underwent whole-body PET. High FDG uptake was noticed in his right maxilla. MRI demonstrated a soft tissue mass obstructing the right maxillary sinus. Laboratory tests, including leukocyte counts and C-reactive protein levels, were normal. Since the distinction between a neoplasm and inflammation was difficult, surgery was performed. During surgery, the mass was discovered to be fragile, and was easily removed. Pathology sections of the resected maxillary sinus mucosa demonstrated marked plasma cell infiltration in the edematous lamina propria mucosae. These plasma cells exhibited no cellular atypia, and no apparent formation of granulation tissue was found. Pathological diagnosis was chronic maxillary sinusitis. This case suggests that plasma cell-rich lesions may exhibit high glucose utilization, although the etiology of hypermetabolism in plasma cells remains unknown.