99Tcm (v) DMSA: the pituitary sign.

Technetium-99m (99Tcm) (v) dimercaptosuccinic acid (DMSA) is a new tumour imaging agent which has been used to evaluate head and neck tumours. It has a normal head and neck biodistribution to include the lacrimal glands, nasal mucosa and the blood-pool. Seventy-seven patients were studied of whom 63 had a head and neck malignancy. Of these patients, 19 (25%) exhibited positive accumulation of radioactivity in the region of the pituitary gland and this was a constant finding in those followed-up after treatment. Biodistribution studies in forty New Zealand white rabbits confirmed pituitary accumulation of 99Tcm (v) DMSA. The pituitary gland region should be included in the normal biodistribution of 99Tcm (v) DMSA.