peripheral nerve sheath tumor; growth that arises from protective lining around peripheral nerves скачать в хорошем качестве

peripheral nerve sheath tumor; growth that arises from protective lining around peripheral nerves

Peripheral nerve sheath tumors (PNSTs) are a diverse group of neoplasms that arise from the cells surrounding peripheral nerves, including Schwann cells, perineurial cells, and fibroblasts. They range from benign to malignant and can occur anywhere in the body. 🧠 Classification of PNSTs Type Description Schwannoma Benign, encapsulated tumor from Schwann cells; often solitary and slow-growing Neurofibroma Benign, non-encapsulated; may be solitary or associated with NF1 Plexiform Neurofibroma Diffuse, infiltrative variant; pathognomonic for NF1 Perineurioma Benign tumor from perineurial cells; rare Hybrid Tumors Show features of more than one PNST type Malignant PNST (MPNST) Aggressive sarcoma; often arises in NF1 patients or from pre-existing lesions 🔬 Histopathological Features Schwannoma: Biphasic pattern: Antoni A (dense) and Antoni B (loose) areas Verocay bodies: aligned nuclei with acellular zones Strong S100 positivity Neurofibroma: Mixed cellularity: Schwann cells, fibroblasts, mast cells Wavy nuclei in collagenous stroma S100 positive but less intense than schwannoma MPNST: Highly cellular with spindle cells Necrosis, mitotic figures, and nuclear atypia Variable S100 expression; often requires additional markers (e.g., SOX10, CD34) 🧬 Genetic Associations NF1 (Neurofibromatosis Type 1): Mutation in NF1 gene (neurofibromin) Associated with neurofibromas and MPNSTs NF2 and Schwannomatosis: Linked to multiple schwannomas ⚠️ Clinical Presentation Localized pain or mass Neurological deficits due to nerve compression In MPNST: rapid growth, pain, and possible metastasis #peripheralvision #nerve #sheath #tumor