Abstract
Cardiac metastasis and hypertrophic osteoarthropathy are both quite rare. We describe a patient presenting with hypertrophic osteoarthropathy as the first symptom of recurrent infantile fibrosarcoma (IF). During surgical resection of lung metastasis, the patient suffered sudden cardiac arrest. Autopsy demonstrated a metastatic lesion in the intraventricular septum of the heart, which is previously undescribed in the literature. This case demonstrates that IF can be aggressive despite its more typical benign course.