Sandbox:DDx HEENT

• 65 yo women
• Rapidly enlarging neck mass
• Neck pain, dyspnea, dysphagia, and hoarseness
• Constitutional symptoms

• Tender hard nodular goiter
• Extensive lymphadenopathy

• Pleomorphic giant cells separated by connective tissue septae
• Cavernous blood filled sinuses resembling aneurysmal bone cyst
• Spindle cells resembling sarcoma
• Squamoid cells that are relatively undifferentiated but also appear epithelial with occasional focal keratinization

Patterns are often mixed with better differentiated cells palisading at necrotic edges and with precursor well differentiated carcinoma; Necrosis Vascular invasion Increased mitotic activity Rhabdoid inclusions

• BRAF gene mutation
• p53 gene mutation