Primary solitary fibrous tumor of the thyroid gland: A review starting from a case report

Ion Negură, Victor Ianole, Radu Dănilă, Maria-Christina Ungureanu, Delia Gabriela Ciobanu Apostol


Primary solitary fibrous tumor (SFT) of the thyroid gland is a rare mesenchymal tumor with fibroblastic differentiation, ramified, thin-walled, enlarged (staghorn) vessels and specific NAB2-STAT6 gene fusion, which is more commonly found in pleura and peritoneum. This neoplasm can be located in a variety of anatomical sites outside pleura and peritoneum including bone, visceral organs and soft tissues, head and neck examples representing only 10-15% of the extra-pleural and extra-peritoneal tumors. Diagnosing this entity can be difficult, especially in thyroid gland, mainly because of the rarity of this neoplasm, but presence of characteristic microscopic features together with positivity for STAT6 and CD34 can confirm the diagnosis and exclude other differential diagnosis. Information about the diagnosis and treatment options of thyroid SFTs is limited but almost all primary thyroid SFTs have a good prognosis and indolent clinical course. Clinical surveillance is still necessary because some SFTs can be aggressive. Raising awareness regarding extra-pleural and extra-peritoneal location of this tumor in endocrine organs can help to better manage these patients. We report the case of a 34-year-old female with primary SFT of the thyroid gland. Additionally, we review the literature for the main clinical, paraclinical and pathological features of this neoplasm.


solitary fibrous tumor; thyroid; mesenchymal neoplasm; CD34; BCL-2; STAT6

Full Text:



Davanzo B, Emerson RE, Lisy M, Koniaris LG, Kays JK. Solitary fibrous tumor. Transl Gastroenterol Hepatol. 2018; 3:94. https://doi:org/10.21037/tgh.2018.11.02.

Chmielecki J, Crago AM, Rosenberg M, et al. Whole-exome sequencing identifies a recurrent NAB2-STAT6 fusion in solitary fibrous tumors. Nat Genet. 2013; 45(2):131-132. .

Huang SC, Huang HY. Solitary fibrous tumor: An evolving and unifying entity with unsettled issues. Histol Histopathol. 2019; 34(4):313-334. .

Klemperer P, Rabin CB. Primary neoplasms of the pleura. A report of five cases. Arch Pathol. 1931; 11:385-412.

Doyle LA, Vivero M, Fletcher CD, Mertens F, Hornick JL. Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics. Mod Pathol. 2014; 27(3):390-395.

Schweizer L, Koelsche C, Sahm F, et al. Meningeal hemangiopericytoma and solitary fibrous tumors carry the NAB2-STAT6 fusion and can be diagnosed by nuclear expression of STAT6 protein. Acta Neuropathol. 2013; 125(5):651-658.

Larsen SR, Godballe C, Krogdahl A. Solitary fibrous tumor arising in an intrathoracic goiter. Thyroid. 2010; 20(4):435-437.

Suh YJ, Park JH, Jeon JH, Bilegsaikhan SE. Extrapleural solitary fibrous tumor of the thyroid gland: A case report and review of literature. World J Clin Cases. 2020; 8(4):782-789.

Mizuuchi Y, Yamamoto H, Nakamura K, et al. Solitary fibrous tumor of the thyroid gland. Med Mol Morphol. 2014; 47(2):117-122.

Taccagni G, Sambade C, Nesland J, Terreni MR, Sobrinho-Simões M. Solitary fibrous tumour of the thyroid: clinicopathological, immunohistochemical and ultrastructural study of three cases. Virchows Arch A Pathol Anat Histopathol. 1993; 422(6):491-497.

Mohamed A, Qureshi F, Eldin RS. Solitary fibrous thyroid tumor: A case report. J Endocr Soc. 2021; 5(1 Suppl):A900-901.

Papi G, Corrado S, Uberti ED, Roti E. Solitary fibrous tumor of the thyroid gland. Thyroid. 2007; 17(2):119-126.

Thompson LDR, Wei C, Rooper LM, Lau SK. Thyroid gland solitary fibrous tumor: report of 3 cases and a comprehensive review of the literature. Head Neck Pathol. 2019; 13(4):597-605.

Song Z, Yu C, Song X, Wei L, Liu A. Primary solitary fibrous tumor of the thyroid - report of a case and review of the literature. J Cancer. 2011; 2:206-209.

Saeed O, Zhang S, Cheng L, Lin J, Alruwaii F, Chen S. STAT6 expression in solitary fibrous tumor and histologic mimics: a single institution experience. Appl Immunohistochem Mol Morphol. 2020; 28(4):311-315.

Tariq MU, Din NU, Abdul-Ghafar J, Park YK. The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior. Diagn Pathol. 2021; 16(1):32.

Han Y, Zhang Q, Yu X, et al. Immunohistochemical detection of STAT6, CD34, CD99 and BCL-2 for diagnosing solitary fibrous tumors/hemangiopericytomas. Int J Clin Exp Pathol. 2015; 8(10):13166-13175. PMID:26722515.

Hasegawa T, Matsuno Y, Shimoda T, Hirohashi S, Hirose T, Sano T. Frequent expression of bcl-2 protein in solitary fibrous tumors. Jpn J Clin Oncol. 1998; 28(2):86-91.

Geramizadeh B, Marzban M, Churg A. Role of immunohistochemistry in the diagnosis of solitary fibrous tumor, a review. Iran J Pathol. 2016; 11(3):195-203. PMID:27799967.

Mordenti P, Di Cicilia R, Delfanti R, Capelli P, Paties C, Cavanna L. Solitary fibrous tumors of the pleura: a case report and review of the literature. Tumori. 2013; 99(4):e177-183.

Ronchi A, Cozzolino I, Zito Marino F, et al. Extrapleural solitary fibrous tumor: A distinct entity from pleural solitary fibrous tumor. An update on clinical, molecular and diagnostic features. Ann Diagn Pathol. 2018; 34:142-150.

Kao YC, Lin PC, Yen SL, et al. Clinicopathological and genetic heterogeneity of the head and neck solitary fibrous tumours: a comparative histological, immunohistochemical and molecular study of 36 cases. Histopathology. 2016; 68(4):492-501.

Kant R, Davis A, Verma V. Thyroid nodules: advances in evaluation and management. Am Fam Physician. 2020; 102(5):298-304. PMID:32866364

Ning S, Song X, Xiang L, Chen Y, Cheng Y, Chen H. Malignant solitary fibrous tumor of the thyroid gland: report of a case and review of the literature. Diagn Cytopathol. 2011; 39(9):694-699.

Parwani AV, Galindo R, Steinberg DM, Zeiger MA, Westra WH, Ali SZ. Solitary fibrous tumor of the thyroid: cytopathologic findings and differential diagnosis. Diagn Cytopathol. 2003; 28(4):213-216.

Tani E, Wejde J, Åström K, Wingmo IL, Larsson O, Haglund F. FNA cytology of solitary fibrous tumors and the diagnostic value of STAT6 immunocytochemistry. Cancer Cytopathol. 2018; 126(1):36-43.

Tanahashi J, Kashima K, Daa T, et al. Solitary fibrous tumor of the thyroid gland: report of two cases and review of the literature. Pathol Int. 2006; 56(8):471-477.

Cameselle-Teijeiro J, Manuel Lopes J, Villanueva JP, Gil-Gil P, Sobrinho-Simões M. Lipomatous haemangiopericytoma (adipocytic variant of solitary fibrous tumour) of the thyroid. Histopathology. 2003; 43(4):406-408.

Koelsche C, Schweizer L, Renner M, et al. Nuclear relocation of STAT6 reliably predicts NAB2-STAT6 fusion for the diagnosis of solitary fibrous tumour. Histopathology. 2014; 65(5):613-622.

Cameselle-Teijeiro J. Uncommon tumors of the thyroid gland. Int J Surg Pathol. 2010; 18(3 Suppl):S205-208.

Corrado S, Corsello SM, Maiorana A, et al. Papillary thyroid carcinoma with predominant spindle cell component: report of two rare cases and discussion on the differential diagnosis with other spindled thyroid neoplasm. Endocr Pathol. 2014; 25(3):307-314.

Takada N, Hirokawa M, Ito M, et al. Papillary thyroid carcinoma with desmoid-type fibromatosis: A clinical, pathological, and immunohistochemical study of 14 cases. Endocr J. 2017; 64(10):1017-1023.

Folpe AL, Lloyd RV, Bacchi CE, Rosai J. Spindle epithelial tumor with thymus-like differentiation: a morphologic, immunohistochemical, and molecular genetic study of 11 cases. Am J Surg Pathol. 2009; 33(8):1179-1186.

Chen G, Liu Z, Su C, et al. Primary peripheral nerve sheath tumors of the thyroid gland: A case report and literature review. Mol Clin Oncol. 2016; 4(2):209-210.

Zhang Y, Tang H, Hu H, Yong X. A rare primary tumor of the thyroid gland: a new case of leiomyoma and literature review. Clin Med Insights Oncol. 2018; 12:1179554918813535.

Canu GL, Bulla JS, Lai ML, et al. Primary thyroid leiomyosarcoma: a case report and review of the literature. G Chir. 2018; 39(1):51-56.

Miettinen M. Smooth muscle tumors of soft tissue and non-uterine viscera: biology and prognosis. Mod Pathol. 2014; 27(1 Suppl):S17-29.

Kandil E, Abdel Khalek M, Abdullah O, et al. Primary peripheral nerve sheath tumors of the thyroid gland. Thyroid. 2010; 20(6):583-586.

Dhar H, Dabholkar JP, Kandalkar BM, Ghodke R. Primary thyroid schwannoma masquerading as a thyroid nodule. J Surg Case Rep. 2014; 9:rju094.

Miettinen M, McCue PA, Sarlomo-Rikala M, et al. Sox10--a marker for not only schwannian and melanocytic neoplasms but also myoepithelial cell tumors of soft tissue: a systematic analysis of 5134 tumors. Am J Surg Pathol. 2015; 39(6):826-835.

Bohlok A, El Khoury M, Bormans A, et al. Schwannoma of the colon and rectum: a systematic literature review. World J Surg Oncol. 2018; 16(1):125-136.

Ghasemi-Rad M, Wang KY, Jain S, Lincoln CM. Solitary fibrous tumor of thyroid: a case report with review of literature. Clin Imaging. 2019; 53:105-107.

Baldi GG, Stacchiotti S, Mauro V, et al. Solitary fibrous tumor of all sites: outcome of late recurrences in 14 patients. Clin Sarcoma Res. 2013; 3:4.

Colia V, Provenzano S, Morosi C, et al. Solitary fibrous tumour presenting with a single bone metastasis: report of six cases and literature review. Clin Sarcoma Res. 2016; 6(1):16.

Demicco EG, Park MS, Araujo DM, et al. Solitary fibrous tumor: a clinicopathological study of 110 cases and proposed risk assessment model. Mod Pathol. 2012; 25(9):1298-1306.

Salas S, Resseguier N, Blay JY, et al. Prediction of local and metastatic recurrence in solitary fibrous tumor: construction of a risk calculator in a multicenter cohort from the French Sarcoma Group (FSG) database. Ann Oncol. 2017; 28(8):1979-1987.


Copyright (c) 2021 Ion Negură, Victor Ianole, Radu Dănilă, Maria-Christina Ungureanu, Delia Gabriela Ciobanu Apostol

Creative Commons License
Archive of Clinical Cases is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.


ISSN: 2360-6975