Not all well-differentiated cutaneous squamous cell carcinomas are equal: Tumors with disparate biologic behavior have differences in protein expression via digital spatial profiling

Abstract

To the Editor: The vast majority of well-differentiated cutaneous squamous cell carcinomas (SCCs) have an excellent prognosis with rare locally aggressive behavior or metastasis. Current staging systems are largely unable to prognostically stratify more indolent forms of cutaneous SCC, particularly on superficial shave biopsies that are partial samples of a significantly larger tumor. However, on a clinical, experiential basis, certain well-differentiated squamous lesions (eg, true keratoacanthoma that regresses spontaneously or keratoacanthoma-like tumors that tend to occur on the lower portion of the legs of women with sun-damaged skin and which have indolent behavior) have a recognizable clinical presentation, particularly with clinical follow up1 or genetic sequencing.