A Rare Septal Hamartoma of Mature Cardiac Myocytes Manifesting With Cardiac Cachexia in a Teenager

Hamartomas of mature cardiac myocytes are a rare type of primary cardiac tumor, with only 5 cases of interventricular septal involvement reported to date. They are often challenging to diagnose, and there is currently no standardized approach to surgical resection. Here, we present a rare case of a large 6.0 × 4.4 × 3.8-cm interventricular septal hamartoma that manifested with cardiac cachexia in a teenage patient. Surgical biopsy was used after 4 attempts at endomyocardial biopsy were nondiagnostic, and partial debulking was performed as complete resection was not feasible.

Atypical Presentation of Right Ventricular Cardiac Hamartoma in a Young Man

Cardiac tumors in adults are exceedingly rare and usually benign. We describe a 29-year-old man with a previous diagnosis of interventricular septal hypertrophy who presented with increasing severity of dyspnea and fatigue. Work-up revealed a 4.9 × 3.7 cm mass at the base of the interventricular septum. Biopsy revealed a benign cardiac hamartoma atypically located in the right ventricle, and the mass was resected via right ventriculotomy.

A Rare Case of Cardiac Mesenchymal Hamartoma and Comprehensive Review of the Literature With Emphasis on Histopathology

Hamartomas are primary, benign neoplastic lesions that most commonly derive from a single variably differentiated cell lineage. Here, we report an unusual case of a cardiac hamartoma. A 62-year-old woman presented with chest pain and palpitations. Serial imaging revealed a large slowly growing and highly vascularized left ventricular mass, which required surgical resection. Microscopically, the lesion was composed of nodular fibrovascular proliferation with haphazardly embedded muscle bundles and peripheral calcifications. Immunohistochemical studies revealed prominent muscle-specific actin positive and smooth muscle actin positive muscle fiber bundles within a disorganized fibrovascular stroma. This characterization is most consistent with cardiac mesenchymal hamartoma. Relevant differential diagnoses for this lesion include hamartoma of mature cardiac myocytes (HMCMs) and intramuscular hemangioma. The prominent smooth muscle differentiation of muscle bundles was incompatible with defining features of HMCM. Absence of S100-positive nerve and mature adipose cells distinguished this lesion from the recently defined, heterogeneous cardiac mesenchymal hamartoma. Forty-seven cases of cardiac hamartoma reported from 1970 to 2020 were reviewed to provide histopathologic context.

How does knowledge of the blood supply to an intracardiac tumour help?

Myxoma is a common benign tumour found in the heart. On reviewing literature, we found some left atrial myxomas receive blood supply from the right coronary artery. Performing a coronary angiogram in a cardiac tumour has the following uses: (1) it shows the vascularity that can be ligated by the surgeon at operation; (2) if there is a blood supply visible, it may not be an intracardiac thrombus; (3) the coronary angiogram may detect a myxoma even before an echocardiogram does so; (4) some myxomas may bleed into the right atrium or left atrium and this may be seen on coronary angiography. We show here the neovascularity of a left atrial myxoma and its blood supply from the right coronary artery. We recommend that all routine coronary angiograms be reviewed carefully for any signs of tumour vascularity or tumour blush as this would prevent missing early myxomas. Echocardiography is the gold standard for detection of myxomas but literature has a number of intracardiac tumours that were detected only by the tumour blush. Some left atrial tumours have been treated by occluding their blood supply.The absence of a blood supply on coronary angiography could rule out a benign cardiac tumour that usually has a blood supply.

Cardiac Hamartoma: A Diagnostic Challenge

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Cardiac hamartoma is a rare clinical entity with hypertrophied myocytes mixed with fibro-vascular and fatty tissues.

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Multi-modality imaging is needed to narrow the differential diagnosis.

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Surgical resection can lead to the definitive diagnosis in some cases.

Prenatal diagnsis of intracardiac hamartoma and Turner syndrome

Turner syndrome is associated with a higher frequency of heart defects detected prenatally when compared to postnatal reports. The most common heart defects detected prenatally are hypoplastic left heart syndrome and coarctation of the aorta. We report a case involving a fetus at 16 gestational weeks with a septated cystic hygroma located on the neck and head, an interventricular septal mass, a hypoplastic left ventricle due to aortic stenosis, mitral stenosis, and a hypoplastic aortic arch with a karyotype of mos 45, X, [47 cells]/47, XXX [3 cells]. The autopsy findings confirmed our prenatal diagnosis with a final diagnosis of Turner syndrome and congenital cardiac vascular malformation.