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What is A 69-yrs-old man with a 60 pack-year history for smoking presents with dizziness and visual disturbances. Physical examination reveals a purplish discoloration of his face, arms, and neck; retinal vein engorgement; and visible distention of his neck veins. His complete blood count reveals a normocytic anemia. The pathophysiology of this patient's clinical presentation most likely involves and explain in detail?
The patient has the superior vena caval syndrome (SVCS). Malignancy accounts for 80% to 90% of cases of SVCS. Most cases are caused by a primary lung cancer extending into the neck and obstructing the superior vena cava. Clinically, patients have a puffy face with a blue to purple discoloration of the face, arms, and shoulders. Retinal vein engorgement results from increased venous pressure. Central nervous system findings include dizziness, convulsions, and visual disturbances. Increased venous pressure is noted in the upper extremities. The diagnosis is confirmed by venography, and the prognosis is poor.