Content area
Full Text
Context.-Primary cardiac tumors are rare and the great majority are benign neoplasms. Mass-forming reactive and pseudoneoplastic growths are less common, but recognizing and distinguishing these lesions from the neoplasms they resemble is critical to appropriate patient care.
Objective.-The general clinical, imaging, gross pathologic, and histologic features of 5 important pseudoneoplasms (inflammatory myofibroblastic tumor, hamartoma of mature cardiac myocytes, mesothelial/monocytic cardiac excrescences, calcified amorphous tumor, and lipomatous hypertrophy of the atrial septum) are discussed, with an emphasis on features differentiating them from other benign and malignant tumors.
Data Sources.-Pertinent citations of the literature and observations from the authors' experience are drawn upon.
Conclusions.-While lacking malignant potential, these lesions can be associated with considerable morbidity and occasional mortality. Their recognition is important in guiding patient management, providing both guidance for appropriate therapy and avoidance of inappropriately aggressive and toxic treatments.
(Arch Pathol Lab Med. 2010;134:362-368)
Tumors of the heart, whether neoplastic or not, are infrequently encountered in surgical or autopsy pathology. Their scarcity and the spectrum of lesions spanning reactive conditions, and both benign and malignant neoplasms, often generate considerable diagnostic difficulty. This section focuses on 5 reactive and "pseudoneoplastic" tumors of the heart, which mimic true neoplasms either grossly (including by clinical imaging) or microscopically, and include (1) inflammatory myofibroblastic tumor (IMT), (2) hamartoma of mature cardiac myocytes (HMCM), (3) mesothelial/monocytic incidental cardiac excrescences (MICE), (4) calcified amorphous tumor (CAT), and (5) lipomatous hypertrophy of the atrial septum (LHAS).
Aspects of these lesions distinguishing them from the neoplasms they may resemble are highlighted. The general clinical, gross, imaging, and histologic features are discussed along with any pertinent genetic or immunophenotypic aspects. While these lesions do not have malignant potential, they are certainly associated with significant morbidity and mortality by affecting valvular function, cardiac conduction/electrical excitability, and by leading to obstruction of blood flow or embolization.
INFLAMMATORY MYOFIBROBLASTIC TUMOR
Fewer than 40 cases of cardiac IMT have been reported, 1,2 though its possible counterpart tumor in other sites (particularly lung, bladder, and intra-abdominal organs) is far more common.3 As mass lesions in the heart com- Accepted for publication July 25, 2008. From the Division of Anatomic Pathology, Mayo Clinic, Rochester, Minn (Dr Miller); and the Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Ariz (Dr...