Left atrial compression by a pericardial hematoma presenting as an obstructing intracavitary mass: a difficult differential diagnosis.

IMPLICATIONS: The differential diagnosis of extracavitary, intramural and intracavitary disease may be difficult. An extrinsic compression of the left atrium by a dissecting pericardial hematoma was misdiagnosed as an intracavitary mass, by echocadiography and computer tomography. This case emphasizes the importance of patient history and clinical setting.