title: Late bone metastasis from an encapsulated follicular carcinoma of the thyroid without capsular and vascular invasion.
abstract: A unique case of encapsulated follicular carcinoma of the thyroid, which lacked histologic evidence of capsular and vascular invasion but developed a late bone metastasis, is described. The thyroid tumor was found in a 42-year-old man. It was relatively small (2.5 cm) and totally encapsulated. Histologically, the thyroid tumor showed a microfollicular growth pattern of follicular cells and revealed no histologic evidence of nuclear atypia, mitotic figures or capsular and vascular invasion. The diagnosis of microfollicular adenoma was made and partial thyroidectomy was performed. Bone (rlb) metastasis of the thyroid tumor developed 22 years after the thyroidectomy. The present case suggested that capsular and/or vascular invasion is not always sufficient for the diagnosis of encapsulated follicular carcinoma of the thyroid.
authors.affiliation: Pathology Section, Kanazawa University Hospital, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Mizukami
authors.forename: A
authors.initials: A
authors.lastname: Nonomura
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.forename: K
authors.initials: K
authors.lastname: Ohmura
authors.forename: T
authors.initials: T
authors.lastname: Michigishi
authors.forename: M
authors.initials: M
authors.lastname: Noguchi
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Ishizaki
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology* / Q000601:surgery; D000236:Adenoma / Q000473:pathology*; D001859:Bone Neoplasms / Q000556:secondary*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D013997:Time Factors; D019043:Vascular Neoplasms / Q000473:pathology