Evaluation of Invasive Squamous Cell Carcinoma, Seborrheic Keratosis and Verruca Vulgaris in Superficial Shave Biopsies using p16, p53, p63, and PHLDA1 Immunohistochemistry

Abstract

Occasionally, the distinction between malignant and benign is challenging in superficial shave biopsies of squamoproliferative lesions. This phenomenon is compounded by the increasing prevalence of conditions encountered that weaken the immune system, such as chemotherapy, immune deficiency diseases, and anti-rejection medications for organ transplantation that have all been shown to increase the risk of the development of squamous cell carcinoma. We collected 30 cases (10 invasive SCC, 10 SK and 10 VV) and performed immunohistochemical staining using a panel approach composed of markers important for proliferation and the cell cycle, including Ki-67, p16, p53, and PHLDA1. The results demonstrate that the invasive SCC group was enriched for high PHLDA1 (80% with PHLDA1 score=3, 100% with PHLDA1 score ≥ 2) and high p53 (50% of SCC with p53 score ≥ 2 vs. 60% of SK and 90% of VV with p53 score=1). The SK group was enriched for low p16 (100% with p16 score ≤ 1) and high p63 scores (100% with p63 score=3). A panel approach may be utilized to help in the distinction between benign keratoses and carcinoma and may be increasingly critical to promote quality care.