Coexistence of Giant Blue Nevus of the Scalp with Hair Loss and Alopecia Areata

A 43-year-old Japanese man exhibited a rare case of a giant cellular blue nevus on the scalp, characterized by a 7 cm grayish macule with sparse hair and histopathological features including spindle-shaped and ovoid melanocytes with abundant melanin. The study noted that giant blue nevi on the scalp, reported in 11 cases, often presented with hair loss and potential cranial invasion. The melanocytes in these nevi had a high potential to damage underlying structures such as bone and hair follicles. Additionally, the patient had alopecia areata on the left temporal region, which responded well to topical corticosteroid treatment.