We describe the case of a 51-year-old woman with a 10-year history of dyspnoea and fatigue on slight effort, presyncopal episodes, and ventricular extrasystolic arrhythmia. Tests were negative for coronary artery disease, valvular disease, or left ventricular dysfunction. The patient fulfilled the clinical criteria for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and the diagnosis was confirmed histologically with an endomyocardial biopsy. During 5-year follow up she also exhibited significant structural progression to the left ventricle. This is a rare case of ARVC/D manifested in middle age, with a negative family history, negative test for desmosome mutations, and negative myocardial immunohistochemical analysis, evidence that tends to suggest an acquired form of the disease. We also present a brief review of the clinical, electrocardiographic, structural, pathological/anatomical and genetic characteristics of the disease, the diagnostic criteria, prognosis, management, and sudden death prevention, as well as the way we have managed our patient until the present day.