Solitary fibrous tumor is a soft tissue neoplasm initially described in the pleura but subsequently reported in the thyroid gland.
The clinical behavior is usually benign, but the existence of aggressive cases has been documented both in the pleura and in extrapleural sites.
Synopsis
age range : 43 to 64 years (mean 52 years)
tumo size: from 2 to 6 cm
white-tan tumor
well circumscribed tumor
— variegated, wavy, storiform, hemangiopericytic or desmoid-like arrangement of spindle cells
trapped thyroid follicles within the tumor
peripheral jagged tumor infiltration among follicles
Immunochemistry
CD34 +
CD99 +
bcl-2 +
Ultrastructure
fibroblastic lineage
Differential diagnosi
benign and malignant mesenchymal tumors of the thyroid
spindle cell follicular adenoma
Riedel thyroiditis
spindle cell and paucicellular variants of anaplastic carcinoma
papillary thyroid carcinoma with exuberant nodular fasciitis-like stroma
spindle epithelial tumor with thymus-like differentiation (SETTL)
See also
fibrous tumors
References
Rodriguez I, Ayala E, Caballero C, De Miguel C, Matias-Guiu X, Cubilla AL, Rosai J. Solitary fibrous tumor of the thyroid gland: report of seven cases. Am J Surg Pathol. 2001 Nov;25(11):1424-8. PMID: 11684960