In diagnostic surgical pathology, the primary use of IHC for soft tissue tumors is to determine the line of differentiation or cell of origin of a mesenchymal neoplasm, aiding in its classification. Soft tissue tumors are a diverse group with overlapping morphological features under routine H&E staining. IHC provides essential clues by detecting expression of specific proteins characteristic of certain lineages. Key applications include: 1) **Confirming mesenchymal origin**: Using markers like vimentin. 2) **Identifying specific lineages**: - Muscle differentiation: Desmin, smooth muscle actin (SMA), myogenin (for skeletal muscle). - Neural/neuroectodermal: S-100 protein, SOX10, GFAP. - Endothelial: CD31, ERG, FLI-1 (for vascular tumors). - Histiocytic: CD68, CD163. 3) **Identifying specific tumor types**: For example, MDM2/CDK4 for well-differentiated liposarcoma, or STAT6 for solitary fibrous tumor. By applying a panel of antibodies, the pathologist can narrow down the diagnosis, which is crucial for prognosis and management, as behavior and treatment vary widely among soft tissue sarcomas.

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Zambia

• Joseph Soko – 101 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies