title: Squamous cell carcinoma arising in a tall cell papillary carcinoma of the thyroid.
abstract: Transformation of differentiated thyroid cancer into poorly differentiated carcinoma is rare. This report describes a case in which preoperative fine needle aspiration suggested a squamous cell carcinoma whereas needle core biopsy favoured an undifferentiated carcinoma of probable thyroid origin. Histology of the subsequent total thyroidectomy specimen revealed a biphasic tumour comprising areas of tall cell papillary carcinoma merging with moderately to poorly differentiated squamous cell carcinoma. The immunohistochemical findings are discussed in detail.
authors.affiliation: Department of Histopathology, Great Western Hospital, Swindon and Marlborough NHS Trust, Marlborough Road, Swindon SN3 6BB, UK.
authors.forename: J
authors.initials: J
authors.lastname: Sutak
authors.forename: J S
authors.initials: JS
authors.lastname: Armstrong
authors.forename: J E
authors.initials: JE
authors.lastname: Rusby
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D001707:Biopsy, Needle; D002291:Carcinoma, Papillary / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D018198:Mixed Tumor, Malignant / Q000473:pathology*; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000473:pathology*