title: Fine-needle aspiration cytology of unsuspected metastatic thyroid carcinoma initially presenting in bone: report of three cases and a review of the literature.
abstract: We present a series of three cases of unsuspected thyroid carcinoma presenting as bony lesions and initially studied by fine-needle aspiration (FNA). This series consists of two cases of follicular carcinoma and a third case of Hurthle cell carcinoma. FNA was performed on all three lesions. In two of these cases, a definitive diagnosis of metastatic thyroid carcinoma was made based on the FNA material. FNA smears of both follicular carcinomas displayed cohesive clusters of atypical round cells with nuclear overlapping and positive immunoperoxidase staining for thyroglobulin. The aspirates of the Hurthle cell carcinoma were composed of sheets and individually scattered oval oncocytic cells with prominent nucleoli. All three cases demonstrated the presence of marginal vacuoles consistent with "flame" cells. To the best of our knowledge, this is the first series discussing the cytologic features and differential diagnosis of unsuspected thyroid carcinoma initially presenting as metastatic bone lesions.
authors.affiliation: Department of Pathology and Laboratory Medicine, Allegheny University of the Health Sciences, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Smith
authors.forename: J F
authors.initials: JF
authors.lastname: Silverman
mesh_terms: D001707:Biopsy, Needle; D001859:Bone Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000473:pathology*