This medical monograph by Dr. Pietro Rondoni, published in 1946, presents a systematic exploration of cancer (il cancro) from a mid-20th-century clinical perspective. The book addresses the nature, classification, etiology, diagnosis, and treatment approaches to malignant tumors as understood in the immediate post-war period. Drawing on both pathological studies and therapeutic experiences, Rondoni’s work reflects the scientific standards and medical knowledge of its time. With limited technical imaging and a focus on textual analysis, it stands as a historical document of oncology's development in Italy before the advent of modern molecular cancer research.