Inadvertent 2-deoxy-2-[18F]fluoro-D-glucose lymphoscintigraphy: a potential pitfall characterized by hybrid PET-CT

To communicate an important pitfall in positron emission tomography (PET) oncologic staging using 2-deoxy-2-[18F]fluoro-D-glucose (FDG).

A 60-year-old man with a right upper lobe bronchogenic carcinoma was injected with FDG through a cannula in his left cubital fossa, with a small amount of the dose extravasating.

Images obtained one hour post-injection with a positron emission tomography-computerized tomography (PET-CT) scanner demonstrated linear FDG activity running with the left arm brachial vascular bundle and along collateral channels, and accumulation of FDG in a low left axillary lymph node of normal size and CT appearance.

Following inadvertent extravasation, FDG appears to accumulate in regional lymph nodes in the same fashion as bone scanning agents or lymphoscintigraphy colloid. Physicians and technologists need to be aware of this important pitfall in order to avoid the false positive diagnosis of nodal metastases. The ability of PET to demonstrate lymphatics and lymph nodes indicates its possible future use in lymphoscintigraphy.