Two Cases of Intraocular Undifferentiated Pleomorphic Sarcoma.

Introduction: Undifferentiated pleomorphic sarcoma (UPS), formerly known as malignant fibrous histiocytoma, is a high-grade soft tissue sarcoma arising from mesenchymal stem cells. UPSs are rare and account for about 5% of all soft tissue sarcoma. UPSs arising in the head and neck are especially rare, comprising 1-3% of all UPSs.

Frameless image-guided stereotactic brain biopsies: emphasis on diagnostic yield.

Background: Studies regarding frameless stereotactic brain biopsy mainly report high diagnostic yield (DY) as opposed to relatively low diagnostic accuracy. This discrepancy raises the question of the certainty and precision of obtained diagnoses. This article proposes a DY definition encompassing diagnostic certainty and precision according to the World Health Organization (WHO) central nervous system (CNS) tumour classification system.