Undifferentiated pleomorphic sarcoma of the right atrium in an infant

Undifferentiated pleomorphic sarcoma is a high-grade malignant tumour, accounting for one-third of all primary cardiac sarcomas. This paper describes a case of undifferentiated pleomorphic sarcoma in an infant using detailed morphological characterisation, immunohistochemical examination and a brief literature review. Taken together, these data will be useful not only for practicing pathologists but also for researchers of other biomedical fields for the development of procedures for differential diagnoses, investigation of the pathogenesis and development of therapeutic approaches for undifferentiated pleomorphic sarcoma.