Cardiac myxomas: A narrative review

Abstract

Cardiac myxomas are common primary neoplasms of the heart. They are biologically benign but "functionally malignant" because of the potential for embolization. They arise most commonly from the left atrium, but no chambers of the heart are immune. They may be sporadic in the majority but also familial as a part of the Carney complex. Two morphological forms exist: polypoid and papillary. Polypoid myxomas often present with obstructive features, while the papillary forms are more prone to embolization. Histogenesis is still controversial; the current view centres around origin from the primitive pluripotent mesenchymal cells. They may be of giant proportion, be calcified or get infected. Clinical presentation typically involves the triad of intracardiac obstruction, embolic events and constitutional symptoms. Precordial examination findings may simulate those of mitral or tricuspid stenosis. The presence of tumour plop and change of the physical findings with changing position may help differentiation between the two. Echocardiography is the investigation of choice. Echogenic polypoid or papillary mobile mass within the atrial cavity remaining attached to the interatrial septum through a stalk are the tell-tale echocardiographic features. Cardiac magnetic resonance and computed tomographic scanning may have incremental diagnostic value. Histopathological examination reveals abundant loose myxoid stroma with scattered round, polygonal or stellate cells with dense irregular nuclei. Genetic testing may detect mutations in the PRKAR1A gene in the familial form of cardiac myxoma, i.e. the Carney complex. Surgical excision is the mainstay of treatment with low operative mortality, excellent postoperative survival and low recurrence rate. The current trend favours minimal-access surgery with or without robotic assistance. Physicians should have appropriate preparedness to make a timely diagnosis and enthusiastic treatment to avoid potentially fatal complications.

Keywords: Cardiac; Carney Complex; Echocardiography; Embolism; Myxoma; Neoplasm.

Figure 1

Different locations of myxoma. A-C: Cardiac myxoma involving the left atrium (A and C) and the right atrium (B); A, B: The myxoma mass is attached to the atrial septum; C: The tumour is related to the lateral wall of left atrium.

Figure 2

Biatrial myxoma in a 22-yr-old Bangladeshi male. A: 2-D transthoracic echocardiography shows biatrial myxoma arising from the midinteratrial septum; B, C: Tumour mass during and after surgery.

Figure 3

Carney complex in a middle-aged Bangladeshi female. A: Multiple pigmented lentigines distributed symmetrically on the face of the patient; B: 2-D transthoracic echocardiography shows multichamber myxoma involving the left atrium, left ventricle and the right atrium; C: 2-D transthoracic echocardiography of the son of the lady shows myxoma in the right atrium.

Figure 4

Polypoid and papillary myxoma in 2D echocardiography. A: Parasternal long axis view shows a polypoid left atrial myxoma; B: Subcostal view shows a papillary right atrial myxoma with multiple projections.

Figure 5

Papillary myxoma presenting with ischemic stroke. Transesophageal echocardiography shows a fragile papillary myxoma. The young patient presented with acute ischemic stroke.

Figure 6

Giant myxoma in right atrium. A, B: 2D transthoracic echocardiography shows a giant myxoma occupying the major parts of the right atrial cavity. Note the multiple papillary projections evident in (B).

Figure 7

Calcified myxoma in the left atrium. Transesophageal echocardiography shows a large calcified myxoma occupying the left atrial cavity.

Figure 8

Infected myxoma in the left atrium. Transthoracic echocardiography shows a large left atrial myxoma protruding into the left ventricular cavity across the mitral valve. A vegetation with independent mobility is attached to the tumour. The patient presented with prolonged fever with positive blood culture.

Figure 9

Histopathology of myxoma. Histopathological examination shows abundant loose myxoid stroma with scattered round, polygonal or stellate cells with dense irregular nuclei.

Figure 10

Echocardiographic features of myxoma. A, B: Transthoracic echocardiography 2D (A) and M-mode (B) shows a large polypoid mass in the left atrial cavity attached to the interatrial septum by means of a stalk (not visualized here) and protruding into the left ventricular cavity across the mitral valve in diastole.