title: Solitary fibrous tumour of thyroid: report of two cases with immunohistochemical features and literature review.
abstract: Solitary fibrous tumour (SFT) is a rare tumour principally found in adults in the pleural cavity. Extrapleural occurrences are rare. Two cases of SFT of the thyroid gland are described in this paper showing their distinctive microscopical architecture, namely "patternless growth pattern". It is characterized by a bland spindle-cell proliferation alternating hyper- and hypo-cellular areas, keloid-like hyalinization and a focal hemangiopericytoma-like vascular pattern. Tumour cells revealed a diffuse strong positivity for CD34, CD99, bcl-2 and Vimentin, but negativity for Desmin, EMA, AE1/AE3, SMA, S-100 and CD31 antibodies. The differential diagnosis of thyroid SFT includes different types of spindle cell proliferation, benign and malignant mesenchymal tumours, medullary thyroid carcinoma, fasciitis-like papillary carcinoma, and undifferentiated (anaplastic) carcinoma. However, the morphologic and immunohistochemical findings of SFT are so characteristic that this diagnosis seldom represent a difficulty.
authors.affiliation: Dipartimento di Biopatologia e Diagnostica per Immagini, Sezione di Anatomia Patologica and UOC Anatomia Patologica, Università degli Studi di Roma Tor Vergata, Ospedale S. Eugenio, Piazzale dell'Umanesimo n.10, Rome, Italy. santeusanio@med.uniroma2.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Santeusanio
authors.forename: Stefania
authors.initials: S
authors.lastname: Schiaroli
authors.forename: Angela
authors.initials: A
authors.lastname: Ortenzi
authors.forename: Antonino
authors.initials: A
authors.lastname: Mulè
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perrone
authors.forename: Guido
authors.initials: G
authors.lastname: Fadda
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D002277:Carcinoma / Q000175:diagnosis; D018276:Carcinoma, Medullary / Q000175:diagnosis; D002291:Carcinoma, Papillary / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008637:Mesenchymoma / Q000175:diagnosis; D008875:Middle Aged; D054364:Solitary Fibrous Tumors / Q000378:metabolism / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor