title: Capsular pseudoinvasion after fine-needle aspiration of follicular adenomas of the thyroid.
abstract: Two cases of an unusual finding of capsular pseudoinvasion in follicular thyroid adenomas after fine-needle aspiration (FNA) procedures are reported. These capsular breaches were noted along the hemorrhagic needle track, which traversed the normal peripheral thyroid parenchyma into the lesions. A reparative reaction was seen at some points along one of the tracks. Histologic examination also showed extrusion of the tumor parenchyma through the capsular interruption in one case. Surgical pathologists should be aware of this rare complication of FNA of thyroid follicular adenomas as a differential diagnosis of minimally invasive (encapsulated) follicular carcinoma.
authors.affiliation: Section of Surgical Pathology, Hospital Italiano, Montevideo, Uruguay.
authors.forename: J
authors.initials: J
authors.lastname: Vercelli-Retta
authors.forename: E
authors.initials: E
authors.lastname: Almeida
authors.forename: G
authors.initials: G
authors.lastname: Ardao
authors.forename: A M
authors.initials: AM
authors.lastname: Paseyro
authors.forename: G
authors.initials: G
authors.lastname: Pedreira
authors.forename: R
authors.initials: R
authors.lastname: Morelli
authors.forename: O
authors.initials: O
authors.lastname: Balboa
mesh_terms: D000236:Adenoma / Q000473:pathology*; D001707:Biopsy, Needle / Q000009:adverse effects*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D013964:Thyroid Neoplasms / Q000473:pathology*