Persistent melanoma is defined as the persistent growth of a residual, incompletely excised primary malignant melanoma
. It typically presents as a variably pigmented persistent or recurring flat patch with poorly defined borders near the scar of the primary excision site. Particularly susceptible to incomplete excision is desmoplastic melanoma
, due to its poorly defined borders, and amelanotic lentigo maligna
. Accordingly, persistent melanomas are more common on the head and neck than at other locations.
The prognosis for persistent melanoma is assessed in the same manner as that of the original tumour
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
IARC Press: Lyon 2005