The rate of occult invasive disease within biopsy-proven squamous cell carcinoma in situ (SCCIS) is not well defined.
To examine the rate of occult invasion in SCCIS.
An institutional-wide pathology database was retrospectively searched for “squamous cell carcinoma in situ” over a 6-year period, and the treatment modality and final pathology results were analyzed for evidence of invasion. In addition, consecutive tumor blocks from Mohs micrographic surgery (MMS) cases of SCCIS were prospectively analyzed for invasion.
The rate of occult invasion for biopsy-proven SCCIS treated with excision was 4.0% (N = 49) and for the MMS margins was 3.5% (N = 310). For the prospective MMS tumor block analysis, the rate of occult invasion was 10.1% (N = 69). No clinical factors (age, sex, location, or size) correlated with increased risk of invasion. All invasive SCCs detected were superficial and well differentiated.
The rate of occult invasion for biopsy-proven SCCIS ranged from 3.5% to 10.1%. The detected rate of invasion varies based on the method of excision and pathology processing of specimens. The rate of invasion should be considered when managing SSCIS.
*Division of Dermatology, UCLA, Los Angeles, California;
†Memorial Sloan Kettering Cancer Center Dermatology Service, New York, New York;
‡Department of Dermatology, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile;
§Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
Address correspondence and reprint requests to: Emily Newsom, MD, UCLA Division of Dermatology, 200 Medical Plaza Driveway, Suite 450, Los Angeles, CA 90024, or e-mail: firstname.lastname@example.org
This research was funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.
The abstract was presented at the American Society for Dermatologic Surgery Annual Meeting 2016 November 12; New Orleans.
The authors have indicated no significant interest with commercial supporters.