**Question:** Most common primary tumour of the heart:

A. Myxoma
B. Lipoma
C. Sarcoma
D. Angiosarcoma

**Core Concept:**
The heart is a complex organ responsible for pumping blood throughout the body. Primary cardiac tumours are rare and can be benign or malignant. Among these, myxomas are the most common type.

**Why the Correct Answer is Right:**
Myxomas are benign, slow-growing tumours that originate from the cardiac muscle cells (cardiomyocytes) or connective tissue cells (fibrocytes) found in the heart's atria and ventricles. They are usually solitary and have a gelatinous appearance due to their mucoid matrix.

**Why Each Wrong Option is Incorrect:**

A. Lipomas are benign tumours that develop from adipose tissue. They are typically found in subcutaneous tissues and muscles, but not in the heart.
B. Sarcomas are malignant tumours that arise from connective tissue cells, such as fibroblasts, myofibroblasts, or endothelial cells. Sarcomas are less common than myxomas.
C. Angiosarcomas are malignant tumours originating from vascular endothelial cells. They are less common than myxomas and lipomas.

**Clinical Pearl:**
Myxomas are usually solitary and cause symptoms like dyspnoea, chest pain, and palpitations. Surgery is the treatment of choice, as myxomas can be removed en bloc without damaging the surrounding cardiac tissue.

**Correct Answer:** D. Angiosarcoma

Myxomas are the most common primary cardiac tumours, while angiosarcomas are less common. The other options are either benign (lipomas) or malignant (sarcomas and angiosarcomas), and not the most common primary cardiac tumour.