Solitary fibrous tumour of the thyroid: Clinicopathological, immunohistochemical and ultrastructural study of three cases

Abstract

We describe three cases of solitary fibrous tumour (SFT) arising from thyroid stroma. Grossly, the tumours were clearly delimited but only partly encapsulated. The following histomorphological growth patterns were observed: bundles of cells in storiform configuration; non-structured bundles; prevalence of fibrous matrix; highly cellular, non-structured; prevalence of loose, non-structured extracellular substance; cellular proliferation and vascular spaces in a haemangiopericytic configuration and a lipomatous component. Immunohistochemical investigation demonstrated intense, diffuse vimentin positivity and focal, less intense actin positivity in all three cases. At electron microscopy we observed a primitive cell of mesenchymal type, with cytoplasm poor in organelles and rich in filaments; this cell sometimes presented differentiation characteristics. SFT is at present the most correct term for the lesions presented here despite some morphological characteristics which differ from cases reported in the literature.

Solitary Fibrous Tumour of Thyroid: Report of Two Cases with Immunohistochemical Features and Literature Review

“…Histologically, all except one case displayed the characteristic lack of architectural pattern and the distinctive cytologic findings. One exceptional case had an extensive lipomatous component [17]. No evidence of local recurrence or distant metastases were reported.…”

“…A review of the literature regarding primary thyroid SFT, showed only 19 cases being reported to date ( [7][8][9][10][11][12][13][14][15][16][17] and Table 3). The morphological and immunohistochemical features of SFT of thyroid, including our cases, are identical to pleural-based solitary fibrous tumours.…”

“…With regard to the thyroid gland, only 19 cases have been reported to date [7][8][9][10][11][12][13][14][15][16][17].…”

Solitary fibrous tumor of the kidney: a case report

“…In 40% of cases they are found in subcutaneous tissue; others are located in deep soft tissues of the extremities or extracompartimental in the head and neck region (especially in the orbit), chest wall, mediastinum, pericardium, retroperitoneum and abdnominal cavity region. Other locations, already described, include meninges, spinal cord, periosteum, salivary glands, lungs, thyroid, liver, gastrointestinal tract, adrenal glands, bladder, prostate and testicles (1,2,5,6,(8)(9)(10)(11)13) . Clinically, the patient complains of localized compressive pain.…”

Tumor fibroso solitario del tiroides

“…Pueden presentar degeneración quística. No se ha descrito hemorragia, necrosis ni calcifi cación en ninguno de los casos reportados en tiroides 3,5 . Estos tumores pueden alcanzar un gran tamaño, describiéndose en uno de los casos una masa de 9,7 cm de diámetro 7 .…”