[Hamartoma of mature cardiac myocytes. Autopsy case report]
Insights
A rare cardiac tumor, hamartoma of mature cardiac myocytes (HMCM), was incidentally discovered during an autopsy. This benign lesion showed disorganized cardiac myocytes without signs of proliferation.
Area of Science:
- Cardiovascular Pathology
- Cardiac Tumors
- Histopathology
Background:
- Hamartoma of mature cardiac myocytes (HMCM) is a rare benign myocardial lesion.
- Pseudoneoplastic lesions require accurate histopathological differentiation.
Observation:
- An autopsy revealed an incidental cardiac tumor in the left ventricle and interventricular septum.
- The tumor was unencapsulated, poorly demarcated, and protruded from the myocardial surface.
Findings:
- Microscopic examination showed disorganized, hypertrophic mature cardiac myocytes, some in a herringbone pattern.
- Dilated venules, thickened intramural coronary arteries, and connective tissue bands were noted.
- Immunohistochemistry for MIB1 was negative, indicating no proliferative activity.
Implications:
- This case expands the understanding of HMCM presentation and histology.
- Accurate diagnosis of HMCM is crucial to distinguish it from malignant cardiac tumors.
- Further research into the pathogenesis of HMCM may be warranted.
Abstract:
Hamartoma of mature cardiac myocytes (HMCM) is a rare benign pseudoneoplastic myocardial lesion. We describe a case of 39-year-old Bulgarian woman living in the Czech Republic, who died because of rupture of anterior communicating artery aneurysm, and severe bronchopneumonia. An incidental finding at the autopsy was a whitish unencapsulated and not sharply demarcated tumor of the left ventricle and adjacent area of interventricular septum, which protruded above the plane of section. Microscopically the tumor consisted of various different forms of disorganized hypertrophic mature cardiac myocytes without vacuolization of cytoplasm, focally in a "herringbone" pattern. Dilated venules and thickened intramural coronary arteries, and intervening bands of connective tissue were present between cardiomyocytes in the tumor. Immunohistochemical staining of MIB1 for the detection of proliferative activity was completely negative. No inflammatory infiltration, adipose tissue or calcifications were present in the tumor.
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