**Core Concept**
Congenital cysts are abnormal fluid-filled structures present at birth, resulting from developmental anomalies. They can arise from various embryonic tissues and are often found in specific locations. Understanding the origin and characteristics of congenital cysts is essential for accurate diagnosis and management.

**Why the Correct Answer is Right**
Sebaceous cysts, also known as epidermoid or epiderm cysts, are acquired lesions that result from the accumulation of sebum and keratin in the skin. They are not congenital in origin but rather develop over time due to various factors such as trauma, infection, or blockage of the sebaceous glands. Unlike congenital cysts, sebaceous cysts are not present at birth and are not associated with specific embryonic tissues.

**Why Each Wrong Option is Incorrect**
**Option A:** External angular dermoid cysts are congenital cysts that arise from the embryonic dermatoid sinus, a remnant of the omphalomesenteric duct. They are indeed congenital in origin and are characterized by the presence of ectodermal and mesodermal tissues.
**Option C:** Branchial cysts, also known as branchial cleft cysts, are congenital anomalies that result from the incomplete closure of the branchial clefts during embryonic development. They are typically found in the lateral neck and are a classic example of a congenital cyst.
**Option D:** Thyroglossal cysts are congenital anomalies that arise from the remnants of the thyroglossal duct, which forms during embryonic development. They are typically found in the midline of the neck and are a common type of congenital cyst.

**Clinical Pearl / High-Yield Fact**
When encountering a congenital cyst, it's essential to consider the location, clinical presentation, and embryonic origin to determine the correct diagnosis. Congenital cysts can be associated with specific syndromes or conditions, and a thorough understanding of their embryonic development is crucial for accurate diagnosis and management.

**✓ Correct Answer: B. Sebaceous cyst is an acquired lesion, not a congenital cyst.**