Milium of the Nipple

Case Presentation

A 4-year-old boy presented with a 1-year history of a single pearly white papule on the right nipple (Figure 1A). No previous skin inflammation or trauma was observed at the same location. The left nipple was normal. His growth and psychomotor development were normal. The dermoscopy showed a pearly white rounded structure with branching vessels (Figure 1B). Histopathology showed an epidermoid cyst containing keratinous material (Figure 1C). The diagnosis of milium was made.

Figure 1.

(A) A single pearly white papule on the right nipple. (B) The dermoscopy showed a pearly white rounded structure with branching vessels. (C) Histopathology showed an epidermoid cyst containing keratinous material (H&E; ×100 magnification)

Teaching Point

Milium is a common benign keratinous cyst characterized by pearly white dome-shaped lesion of 1 mm to 4 mm in diameter, but the involvement of the nipple seems to be rare and bigger. Milium may occur as either primary or secondary lesions. Four cases of milium involving the nipple were found by searching PubMed databases [1,2]. Among them, the male-to-female ratio was 1:3; the age range was from 6 to 16 months. They presented a unilateral single pearly white dome-shaped papule with a diameter of 3 mm to 8 mm. Three cases underwent surgical excision, and 1 spontaneously disappeared. The dermoscopic manifestation shows a white or yellowish-white rounded structure with linear or branching vessels. The differential diagnosis includes molluscum contagiosum, calcinosis cutis, juvenile xanthogranuloma, and syringoma.