BACKGROUND: Surgical exploration in the region of the neck identifies
a majority of parathyroid adenomas; however, in individuals in whom su
rgical exploration has failed, fine needle aspiration (FNA) biopsy can
be useful. Ectopic parathyroid adenomas can be rapidly diagnosed by t
he cytologic appearance of aspirate smears with the identification of
stromal and intracellular lipid on oil red O-stained smears. CASE: A 5
9-year-old male presented with hyperparathyroidism; surgical explorati
on of the neck in the region of the thyroid gland failed to identify a
ny parathyroid abnormality. Subsequent imaging with (99m)technetium an
d (201)thallium showed a mass in the left supraclavicular region that,
on FNA biopsy, was confirmed as an ectopic adenoma. Removal of the ad
enoma resulted in normal serum calcium levels. CONCLUSION: FNA can be
successfully utilized in the localization of ectopic parathyroid tissu
e.