Actinic Keratosis, Transected: What Lies Beneath?

Abstract

Evaluation of superficial transected shave biopsies of squamous neoplasms often presents a diagnostic dilemma for the dermatopathologist because of the lack of complete visualization of the base of the epidermis. Fear of "missing" an invasive carcinoma must be balanced with avoidance of overdiagnosis of precancerous actinic keratosis (AK), especially on cosmetically sensitive areas such as the face. If a concern exists that a more invasive component may be present, a diagnosis of AK transected at the base (AKT) will often be rendered to alert the dermatologist of this concern. Because of lack of objective data regarding the malignant transformation of this diagnosis, the method of treatment is often based on the clinical appearance of the residual lesion or the lesion is rebiopsied to establish a more definitive diagnosis, costing patient and physician time and increasing health care costs. This study aims to provide objective data regarding (1) how often dermatologists are resampling these lesions and (2) how accurately an AKT diagnosis identifies patient risk for a more aggressive lesion, to establish whether there is a benefit in providing more tissue for the initial biopsy. We performed a retrospective study examining 274 biopsies with a diagnosis of AKT. We found only 27% had follow-up rebiopsy or excision. Of these 73 cases, 63% showed residual AK and 20% showed a more serious lesion, which warrants more aggressive treatment. Because the health care culture slowly shifts to metric-driven medicine and value-based payment, providing objective data for the progression of diagnosis, such as AKT, will be important (1) to aid the clinician in taking adequate tissue samples for diagnosis to make adequately informed management decisions, (2) to reduce the conversion of AK to squamous cell carcinoma, the resultant depth of squamous cell invasion, and the patient's risk of metastases to improve the patient's long-term outcomes, and (3) to decrease the overall cost of the patient's health care by improving the patient's long-term outcomes.