Primary signet ring cell carcinoma of the lung in patient with superior vena cava syndrome and lymphangitic carcinomatosis: a case report - Tropea, Giulia Maria Diletta; Frazzetto, Evelise; Musumeci, Andrea Giuseppe; Farina, Renato; Signorelli, Salvatore Santo (Internal and Emergency Medicine: Official Journal of the Italian Society of Internal Medicine, 2025)