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, keloidlike 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.

Solitary Fibrous Tumor of the Thyroid Gland: A Report of Two Cases with an Analysis of Their Clinical and Pathological Features

“…The two cases of SFT reported here are comparable with the 24 previously published cases of SFT, in terms of gender (12 females and 12 males), mean age (52.5±12 years old), tumor size (1.5 to 9.7 cm), and laterality (11 cases in the right lobe, 11 in the left lobe, and 2 not specified) [1][2][3][4][5][6][7][8][9][10][11][12].…”

Intrathoracic Thyroid Solitary Fibrous Tumor Presenting with Respiratory Failure

“…Including the patient described here, only 25 patients have been reported in the English literature. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The morphologic, immunohistochemical, and ultrastructural features of the thyroid SFTs are similar to their reported counterparts in other anatomic sites and their clinical outcome is similarly benign.…”

“…The clinical symptoms were variable, including asymptomatic thyroid nodule in 14 patients, progressed mass in 8 patients, asthma in 2 patients and hoarseness in one patient. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The duration of symptoms ranged from one month to more than 10 years. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The nonspecific symptoms and image…”

Malignant solitary fibrous tumor of the thyroid: a case-report and review of the literature

“…The size of the tumor can range from 2 to 10 cm, and there is equal incidence for both thyroid lobes (11). The clinical presentation is similar to regular thyroid neoplasms (10).…”

“…At immunohistochemistry, the tumor cells revealed positivity for CD34, bcl-2, CD99, and vimentin, but not for epithelial markers (such as keratins, thyroglobulin), desmin, and S100 protein (10,11).…”