**Core Concept**
Leiomyomas of the esophagus are rare, benign smooth muscle tumors that can cause dysphagia and other esophageal symptoms. Endoscopic treatment is often considered, but it is not suitable for all cases due to the risk of complications.

**Why the Correct Answer is Right**
The correct answer is due to the high risk of bleeding and perforation associated with endoscopic treatment of esophageal leiomyomas. This is because these tumors are often large, fibrotic, and have a high risk of rupture during endoscopic manipulation. The use of caution or the application of endoscopic techniques such as EMR (endoscopic mucosal resection) is usually not sufficient to prevent these complications. **Option C: High risk of bleeding and perforation** is the most accurate answer, as it directly addresses the underlying concern with endoscopic treatment of esophageal leiomyomas.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not specific enough, as it does not address the underlying risk associated with endoscopic treatment of esophageal leiomyomas.
* **Option B:** This option is incorrect, as the risk of malignancy is not the primary concern when considering endoscopic treatment of esophageal leiomyomas.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that endoscopic treatment of esophageal leiomyomas is generally reserved for small, superficial tumors with a low risk of bleeding and perforation. Large or deeply located tumors may require surgical excision for safe removal.

**Correct Answer:** C. High risk of bleeding and perforation.