Surgical Continuity of Care: A Multidisciplinary Approach to Managing the Mohs Micrographic Surgery Positive Deep Margin at the Parotid in Cutaneous Squamous Cell Carcinoma

Abstract

Background:
While high-risk characteristics for cutaneous squamous cell carcinoma (cSCC) and the management of metastatic cSCC have received considerable attention in the literature, standard of care management for the positive MMS margin at the parotid fascia in cSCC has yet to be clarified. The aim of this study is to better define optimal management approaches for the positive deep Mohs Micrographic Surgery (MMS) margin at the parotid fascia.
Methods:
Inclusion criteria for this retrospective case series were patients presenting to the Saint Louis University with biopsy proven cSCC with a positive deep MMS margin at the parotid fascia who were referred to HNS and treated with curative intent. The following data were recorded: age; gender; NCCN high-risk factors; adjuvant surgical, medical, radiation (RT), or chemoradiation (CRT) therapies; outcomes; and follow-up data.
Results:
Eight patients undergoing MMS had a positive deep margin at the parotid fascia. HNS performed 7 parotidectomies and 1 wide local excision (WLE), obtaining negative margins in 75.0% (6/8) of patients (5/7 parotidectomies and 1/1 WLE). Obtaining negative surgical margins (6/8 patients) resulted in a disease free survival (DFS) and overall survival (OS) of 27.8 and 43.6 months, respectively; compared to a DFS of 20.6 months and OS of 39.1 months for positive margins (2/8 patients).
Conclusion: This study demonstrates that resection with negative surgical margins results in excellent long-term local and regional disease control, and overall survival for cSCC patients with positive deep MMS margin at the parotid fascia.