Question

Discussion

The answer is E: palisaded encapsulated neuroma, also known as a solitary circumscribed neuroma. This is a common benign neural tumor that may be misdiagnosed as a carcinoma.¹ It presents as a small (2 to 6 mm), asymptomatic, skin-colored, firm, dome-shaped papule. It most often occurs on the mucocutaneous junction of the face in patients between 40 and 60 years of age. Men and women are equally affected.²

Palisaded encapsulated neuromas usually have no hair on the surface and minimal or absent telangiectasia; however, trauma to the area can cause prominent telangiectatic vessels and ulceration.² Histologically, these neuromas appear as a partially encapsulated dermal nodule. The cause is unknown, but it has been suggested that they are a trauma-induced hyperplasia of the nerve fibers.³ Excision is typically curative.⁴

The most common form of basal cell carcinoma presents as a dome-shaped papule or nodule that may ulcerate and bleed. The raised, rolled, pearly borders can be accentuated by applying traction to the surrounding skin.⁵ Telangiectasia forms an arboreal pattern on dermoscopy.⁶

An epidermal inclusion cyst usually presents as a 1- to 4-cm, solitary, firm, mobile, subcutaneous nodule on the trunk, neck, or face. A white, cheesy material (accumulated keratin debris) can be expressed from the cyst with a surface punctum.⁷

An intradermal melanocytic nevus is a benign lesion that may or may not be pigmented. It is usually soft with smooth edges and retains skin markings.⁸ Brown pigment, comma-shaped vessels, and hair are often noted on dermoscopy.⁹

A solitary neurofibroma presents as a soft sessile or pedunculated papule, usually on the trunk, that invaginates with pressure (“buttonholing”).⁵ Multiple neurofibromas are associated with von Recklinghausen disease, or neurofibromatosis 1. Other clinical features include café au lait spots, axillary freckling, and iris hamartomas (Lisch nodules).