title: Papillary carcinoma of the thyroid with anaplastic transformation: diagnostic pitfalls in fine-needle aspiration biopsy.
abstract: A case of coexistent papillary and anaplastic carcinoma of the thyroid is presented. The diagnosis of papillary carcinoma was made by fine-needle aspiration biopsy (FNAB); however, it did not correspond to the aggressive clinical behavior of the tumor. Subsequent biopsies revealed anaplastic carcinoma in the thyroid and pretracheal tissue. This case most likely represents anaplastic transformation in a pre-existing papillary carcinoma. The limitations of diagnosing this entity by FNAB as well as some possible solutions are discussed.
authors.affiliation: Department of Laboratory Medicine, Ottawa Civic Hospital, Ontario, Canada.
authors.forename: D S
authors.initials: DS
authors.lastname: Vinette
authors.forename: L L
authors.initials: LL
authors.lastname: MacDonald
authors.forename: H M
authors.initials: HM
authors.lastname: Yazdi
mesh_terms: D002277:Carcinoma / Q000175:diagnosis* / Q000473:pathology; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000473:pathology; D002466:Cell Nucleolus / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D003581:Cytodiagnosis; D003593:Cytoplasm / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology