title: Poorly differentiated thyroid carcinoma in a 9-year-old boy: case report.
abstract: Poorly differentiated thyroid carcinoma (PDTC) is a rare disease with a poor prognosis in children. We describe a 9-year-old boy with a thyroid nodule composed of cystic and solid components, which became completely solid and hypoechoic and was subsequently proved to be PDTC. The tumor consisted of small- to intermediate-size round cells in a trabecular or insular pattern with hyperchromatic nuclei and mitotic figures. The tumor cells were positive for thyroid transcription factor 1 and thyroglobulin. PDTC is morphologically and prognostically between the well-differentiated and anaplastic carcinomas. It must be distinguished from the solid variant of papillary carcinoma and well-differentiated follicular carcinoma with a predominantly solid/trabecular growth pattern. The tumor stage was T2N0M0. The patient was treated with total thyroidectomy, left-sided neck level VI lymph node dissection, recombinant human thyrotropin-stimulated 131I ablation therapy, and thyroid-stimulating hormone suppression. Malignancy should be suspected in a cystic thyroid nodule that becomes solid and hypoechoic.
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Yi-Lei
authors.initials: YL
authors.lastname: Wu
authors.forename: Wei-Hsin
authors.initials: WH
authors.lastname: Ting
authors.forename: Shiuan-Li
authors.initials: SL
authors.lastname: Wey
authors.forename: Chi-Kuan
authors.initials: CK
authors.lastname: Chen
authors.forename: Chi-Yu
authors.initials: CY
authors.lastname: Huang
authors.forename: Shih-Ping
authors.initials: SP
authors.lastname: Cheng
authors.forename: Yann-Jinn
authors.initials: YJ
authors.lastname: Lees
mesh_terms: D002454:Cell Differentiation; D002648:Child; D003131:Combined Modality Therapy / Q000379:methods; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D013961:Thyroid Gland / Q000473:pathology* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D016606:Thyroid Nodule / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D013965:Thyroidectomy; D013972:Thyrotropin / Q000037:antagonists & inhibitors
chemical_list: D007457:Iodine Radioisotopes; D013972:Thyrotropin