Note the variable cellularity in these needle biopsies taken from a thoracic solitary fibrous tumor, the site where they were described many years ago. The morphology is characteristic. The strong CD34 expression is against synovial sarcoma, which shares the presence of staghorn shaped blood vessels.
Vintage reference - England DM, Hochholzer L, McCarthy MJ. Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases. Am J Surg Pathol. 1989 Aug;13(8):640-58. Erratum in: Am J Surg Pathol 1991 Aug;15(8):818. PMID: 2665534.
Case provided by Dr. Elizabeth Montgomery, Clinical Professor, Vice Chair of Faculty Development & Mentoring, Director of Surgical Pathology Fellowship Training Program, Co-Director, Pathology Reference Services, and Editor-In-Chief at Innovative Science Press.
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