Basicmedical Key

Ependymoma Elizabeth A. Montgomery, MD Key Facts Terminology Cellular glial or epithelial-appearing neoplasm manifesting ependymal differentiation as either perivascular rosettes or true rosettes Myxopapillary variant has pseudopapillary architecture and intercellular…

Ectopic Meningioma Lester Thompson, MD Cyril Fisher, MD, DSc, FRCPath Key Facts Terminology Benign neoplasm of meningothelial cells Clinical Issues Approximately 0.2% of sinonasal tract and nasopharynx tumors M:F= 1:1.2…

Perineurioma Thomas Mentzel, MD Key Facts Terminology Benign mesenchymal neoplasm composed of neoplastic perineural cells Clinical Issues Progressive muscle weakness &/or sensory disturbances are seen in intraneural perineurioma Extraneural perineurioma…

Nasal Glioma Steven D. Billings, MD Key Facts Terminology Rare congenital anomaly Clinical Issues Subcutaneous mass Bridge of nose most common site 1/3 are intranasal 20% associated with communication to…

Neurofibroma Amitabh Srivastava, MD Key Facts Terminology Benign peripheral nerve sheath tumor with heterogeneous admixture of axons, Schwann cells, perineurial cells, and fibroblasts Most are sporadic; NF1 associated with multiple,…

Schwannoma Amitabh Srivastava, MD Key Facts Terminology Encapsulated, benign peripheral nerve sheath tumor composed predominantly of Schwann cells Clinical Issues Common between 20-50 years of age Affects males and females…

Neuroma Thomas Mentzel, MD Key Facts Terminology Neuroma represents proliferation of peripheral nerve fibers in which ratio of axons to Schwann cell fascicles approaches 1:1 Solitary circumscribed neuroma (“palisaded encapsulated…

Fibrolipomatous Hamartoma Cyril Fisher, MD, DSc, FRCPath Key Facts Terminology Increased fibrofatty tissue infiltrating and surrounding nerves Clinical Issues Median nerve most commonly affected Predominantly in children, including congenitally Macrodactyly…

Myoepithelioma/Mixed Tumor/Parachordoma Thomas Mentzel, MD Key Facts Terminology Neoplasms that are composed of epithelial &/or myoepithelial cellular elements in varying proportions Tumor cells are set in hyalinized to chondromyxoid stroma…

Malignant Mesothelioma Cyril Fisher, MD, DSc, FRCPath Key Facts Terminology Malignant tumor of mesothelial cells arising in pleura, peritoneum, or pericardium Etiology/Pathogenesis Asbestos exposure Amphibole: Crocidolite, amosite Thin long fibers…