A Diagnostic Challenge: Changes in Histopathologic Tumor Diagnosis of Atypical Squamous Proliferations After Surgical Removal.

Background: Biopsy-proven "atypical squamous proliferations" (ASPs) may prove difficult to diagnose histologically because of partial sampling, lack of complete criteria for definitive diagnosis, or overlap of histopathological features with other neoplasms. There are no guidelines concerning the management of ASPs.

Objective: To retrospectively clarify the diagnosis of biopsy-proven ASPs after surgical removal, specifically, to ascertain what fraction represent malignant tumors.

Methods: Medical records of patients who underwent surgical removal of biopsy-proven ASPs in an academic dermatologic surgical unit from June 2008 to July 2013 were examined. The resultant histopathologic diagnosis of these lesions after surgical removal, along with other demographic data, was obtained.

Results: Of the 71 biopsy-proven ASPs that were treated by surgical removal in the study period, 54.9% exhibited resultant pathologic diagnosis of nonmelanoma skin cancer (NMSC).

Conclusion: Biopsy-proven ASPs present a therapeutic challenge. The authors' data illustrate the importance of subsequent tissue sampling, as these lesions often represent NMSCs.