**Question:** All is true about digastric triangle EXCEPT:

A. It is a triangular region located between the anterior border of the digastric muscle and the posterior border of the sternocleidomastoid muscle.
B. It contains the posterior belly of the digastric muscle.
C. It is a site of infection and inflammation.
D. It is a region of lymph node involvement in head and neck cancers.

**Correct Answer:**

D. It is a region of lymph node involvement in head and neck cancers.

**Core Concept:**

The digastric triangle is a clinically relevant anatomic region located in the posterior aspect of the anterior triangle of the neck. It is formed by the anterior border of the digastric muscle, the posterior border of the sternocleidomastoid muscle, and the lower border of the mandible. The triangle contains the posterior belly of the digastric muscle, which is responsible for mandibular depression and elevation.

**Why the Correct Answer is Right:**

Digastric triangle is primarily associated with the anatomy and function of the digastric muscle, not with lymph node involvement or cancer. While it is a distinct anatomic region, it does not directly relate to lymph node status or cancer progression. Therefore, the statement that it is a region of lymph node involvement in head and neck cancers is incorrect.

**Why Each Wrong Option is Incorrect:**

A. The digastric triangle is indeed a triangular region, but the focus here is on its anatomic features (anterior border of the digastric muscle and posterior border of the sternocleidomastoid muscle), not infection or inflammation.

B. While the posterior belly of the digastric muscle is indeed present in the digastric triangle, it is unrelated to the correct answer. The muscle is involved in mandibular movement but does not relate to infections or cancer.

C. Infections and inflammation are not relevant to the digastric triangle, which is a distinct anatomic region. Infections and inflammation would typically affect adjacent structures, such as the submandibular gland or submandibular space, rather than the digastric triangle itself.

**Clinical Pearl:**

The digastric triangle is an essential anatomic landmark in head and neck surgical procedures. Understanding its location and relationship to surrounding structures like the submandibular gland and submandibular space helps surgeons avoid complications during surgeries in this region. However, the correct answer highlights the misconception that the digastric triangle is directly related to infections, inflammation, lymph node involvement, or cancer.