A 5-year-old girl is brought to the physician after her parents noticed red blood in her stool. Physical examination reveals mucocutaneous pigmentation. Small bowel radiography discloses multiple, small- to medium-sized polyps that are diagnosed pathologically as hamartomas. Which of the following is the most likely diagnosis?

**Core Concept**
The question is testing the student's knowledge of gastrointestinal polyps, specifically the characteristic features of Peutz-Jeghers syndrome. This condition is a rare genetic disorder characterized by the presence of hamartomatous polyps in the gastrointestinal tract, along with mucocutaneous melanin deposits.

**Why the Correct Answer is Right**
Peutz-Jeghers syndrome is a hereditary condition caused by mutations in the STK11 (LKB1) gene, which leads to the development of hamartomatous polyps in the small intestine, stomach, and colon. The polyps are typically multiple, small to medium in size, and are often found in the jejunum. The syndrome is also characterized by the presence of mucocutaneous pigmentation, which is a distinctive feature of this condition. The mucocutaneous melanin deposits are usually found on the lips, oral mucosa, and digits.

**Why Each Wrong Option is Incorrect**
**Option A:** Congenital teratoma is a type of tumor that arises from embryonic tissues and is not characterized by the presence of hamartomatous polyps or mucocutaneous pigmentation.

**Option B:** Hyperplastic polyps are a type of non-neoplastic polyp that is typically found in the colon and is not associated with mucocutaneous pigmentation.

**Option D:** Tubular adenoma is a type of neoplastic polyp that is typically found in the colon and is not characterized by the presence of mucocutaneous pigmentation.

**Clinical Pearl / High-Yield Fact**
Peutz-Jeghers syndrome is associated with an increased risk of gastrointestinal and extraintestinal malignancies, including colon cancer, breast cancer, and ovarian cancer. Patients with this condition should undergo regular screening for these malignancies.

**✓ Correct Answer: C. Peutz-Jeghers polyp**

✓ Correct Answer: C. Peutz-Jeghers polyp