Collision of melanocytic nevi and seborrheic keratosis- report of an unusual case

Seborrheic keratosis is the common benign epithelial tumors of the skin with an increasing incidence with age and exposure to UV light. Melanocytic nevus refers to any benign tumor of nevus cell which can be congenital or acquired. The coexistence or the collision of seborrhoic keratosis and meloncytic nevus in the same tissue specimen is very uncommon. In this paper we present a case of collision tumour in a 75 year old farmer who presented with a chief complaint of black moles on his left face since 10 years. On examination they
were soft, non-tender, with irregular surface. Histopathological examination revealed the features of both seborrheic keratosis and junctional nevi in the same lesion suggestive of coexistence of seborrheic keratosis and melanocytic nevi in the same lesion. The present case is unusual because the coexistence of seborrheic keratosis and melanocytic nevi is not a frequent finding in that seborrheic keratosis occurring in association with junctional nevi is extremely rare with only two cases reported in the literature.