**Core Concept**
Atrial myxomas are the most common primary cardiac tumors, arising from the left atrium, particularly from the fossa ovalis. They are typically benign, gelatinous masses composed of myxoid tissue, fibroblasts, and blood vessels.

**Why the Correct Answer is Right**
Atrial myxomas are known to cause obstructive symptoms due to their size and location, often leading to symptoms such as dyspnea, palpitations, and even syncope. They can also cause systemic embolization due to their friable nature, leading to complications such as stroke or peripheral embolism. The most common presenting symptom is a left atrial mass, which can be visualized on echocardiography.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect as atrial myxomas are typically benign, and their growth is not influenced by hormonal factors.
**Option B:** This statement is incorrect as the majority of atrial myxomas are located in the left atrium, not the right.
**Option C:** This statement is incorrect as while atrial myxomas can cause embolic events, they are not typically associated with autoimmune disorders.

**Clinical Pearl / High-Yield Fact**
Atrial myxomas are more common in women, particularly in the 5th decade of life, and are often associated with a family history.

**Correct Answer:** B.