Carcinomatous Invasion of Interventricular Septum Mimicking Endocarditis Vegetation

secondary cardiac tumours are rare and often represent a diagnostic challenge. We report the case of an aortomitral endocarditis associated with a recent history of breast cancer.

during the surgery, an unusual "vegetation-like" lesion was identified on the interventricular septum. Despite clinical and pathophysiological characteristics suggesting an infective endocarditis lesion (bacterial grafting onto an irritative lesion of the interventricular septum, secondary to systolic anterior motion of the mitral valve), histopathological examination revealed carcinomatous infiltration of the interventricular septum.

this case highlights the crucial importance of pursuing anatomopathological analyses in atypical locations of cardiac vegetations, particularly in patients with a history of malignancy, even in remission. Awareness of this diagnostic difficulty can help clinicians to implement rapid and appropriate care.