One hundred recurrent, re-treated basal cell epitheliomas were studied. The original lesions had been treated with curettage and electrodesiccation, excision, or x-radiation. The 100 recurrences were treated by these same modalities, except that five were treated with Mohs' chemosurgery. Following re-treatment, almost half (47) recurred a second time. This inordinately high failure rate after treatment of recurrent basal cell epitheliomas would indicate that such lesions are more difficult to eradicate than primary basal cell epitheliomas, and that their treatment should be aggressive.
Menn H, Robins P, Kopf AW, Bart RS. The Recurrent Basal Cell EpitheliomaA Study of 100 Cases of Recurrent, Re-treated Basal Cell Epitheliomas. Arch Dermatol. 1971;103(6):628-631. doi:10.1001/archderm.1971.04000180054007