Voluminous abdominal gastrointestinal stromal tumor of unknown origin manifested with bleeding in a young man: synchronous management of the emergency and oncological approach—case report - Ferro, Silvia; Fabbri, Nicolò; Galeotti, Roberto; Salviato, Elisabetta; Cavallesco, Giorgio; Pansini, Giancarlo (AME Case Reports; Vol 4 (October 2020): AME Case Reports, 2020)