**Core Concept**
Blue rubber bleb nevus syndrome is a rare disorder characterized by multiple venous malformations, typically presenting with cutaneous lesions that are often accompanied by gastrointestinal and other systemic manifestations. The cutaneous lesions are usually benign, but they can cause significant morbidity due to bleeding and potential complications.

**Why the Correct Answer is Right**
The correct answer to this question is likely **C. Cutaneous lesions**. This is because the blue rubber bleb nevus syndrome is primarily known for its distinctive cutaneous manifestations, which are blue, rubbery, and compressible lesions that typically appear on the skin. These lesions are believed to result from an abnormal formation of blood vessels, specifically dilated veins that are filled with blood. The cutaneous lesions are usually the first sign of the disease and often lead to a diagnosis.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while gastrointestinal involvement is possible in blue rubber bleb nevus syndrome, it is not the most common presentation of the disease.
* **Option B:** This option is incorrect because while systemic manifestations can occur in blue rubber bleb nevus syndrome, they are not the most common presentation.
* **Option D:** This option is incorrect because while bleeding can occur from the cutaneous lesions, it is not the most common presentation of the disease.

**Clinical Pearl / High-Yield Fact**
One important aspect of blue rubber bleb nevus syndrome to remember is that the cutaneous lesions can cause significant morbidity due to bleeding, and patients may require surgical or interventional procedures to manage these lesions.

**Correct Answer: C. Cutaneous lesions**