A newborn had pinkish-blue lesion over upper eyelid. There was no lid edema or eye involvement and the lesion regressed spontaneously at about one year of age. What is the diagnosis?
**Core Concept**
The question is testing the student's knowledge of congenital melanocytic nevi, specifically the characteristics of a common type of lesion that appears at birth or in early infancy.
**Why the Correct Answer is Right**
The description provided is classic for a congenital melanocytic nevus (CMN), also known as a birthmark or nevus congenitalis. CMNs are benign pigmented lesions that are present at birth or appear within the first few months of life. They can be flat or raised, and may be pinkish-blue in color. The lesion in question is likely a CMN that regressed spontaneously, which is a common phenomenon in these types of lesions. The regression of CMNs is thought to be due to the involution of melanocytes, which are the pigment-producing cells that give the skin its color.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not match the description of the lesion. A hemangioma is a vascular lesion that appears as a reddish-purple mark and is often accompanied by lid edema or eye involvement. This does not match the description provided.
* **Option B:** This option is incorrect because it does not match the description of the lesion. A melanoma is a malignant tumor of the skin that can appear at any age, but it is not typically present at birth or in early infancy. Melanomas are also often associated with abnormal pigmentation and may be accompanied by other symptoms such as bleeding or ulceration.
* **Option C:** This option is incorrect because it does not match the description of the lesion. A port-wine stain is a type of vascular malformation that appears as a reddish-purple mark and is often associated with lid edema or eye involvement. This does not match the description provided.
**Clinical Pearl / High-Yield Fact**
It's worth noting that congenital melanocytic nevi are a common type of lesion that can appear at birth or in early infancy. They are usually benign and can regress spontaneously, but they can also increase the risk of developing melanoma later in life. It's essential to monitor these lesions closely and perform regular skin exams to detect any changes or abnormalities.
**Correct Answer:** . Nevus congenitalis.