Acquired melanocytic nevi in Egyptian patients: a clinicopathological study.

Introduction: Melanocytic nevi (MN) are the most important simulants of melanoma. Although acquired nevi are usually clinically stable, they may show abnormal clinical behavior. This study assessed the histological changes and prognosis of acquired MN with changing clinical behavior in Egyptian patients.

Methods: The study included 236 patients that were classified into two groups; Group A included nevi with abnormal clinical presentation and Group B included clinically typical nevi.

Results: Each group included 118 patients with a predominance of female patients. Abnormal clinical presentation in Group A included altered pigmentation (35.6%), rapid enlargement (30.5%), keratotic changes (16.9%), inflammation (7.6%), ulceration (5.1%), and hemorrhage (4.2%). Typical histological features were significantly higher (p = 0.008) in Group B (99.2%) compared with Group A (87.3%). Atypical histological features were significantly higher (p = 0.002) in Group A, with higher numbers of ulcerative and altered pigmented nevi. Malignant changes showed no significant difference (p = 0.47) between the two groups. No relapse was recorded after excision of any lesion.

Discussion: Among Egyptians, changing clinical behavior of MN may show histological atypia but low risk of malignant transformation. Early excision and follow-up of ulcerative and altered pigmented nevi are recommended.