Oral squamous cell carcinoma margin discrepancy after resection and pathologic processing

Purpose: Resecting oral squamous cell carcinoma (SCC) with an appropriate margin of uninvolved tissue is critical in preventing local recurrence and making the decision regarding postoperative radiation therapy, This task can be difficult due to the discrepancy between margins measured intraoperatively and those measured microscopically by the pathologist after specimen processing. The goal of this study is to quantify and compare the amount of margin discrepancy observed based on tumor location and staging. Materials and Methods: Forty-one patients who underwent resective surgery with curative intent for primary oral SCC were included in this study. All patients underwent resection of the tumor with a measured 1 cm margin by one attending surgeon. Specimens were then submitted for processing and reviewing and histopathologic margins were measured. The closest histopathologic margin was compared with the in situ margin (I cm) to determine percentage discrepancy. Percent discrepancies were grouped by locations (buccal mucosa, mandibular alveolar ridge, and retromolar trigone in group 1; maxillary alveolar ridge and palate in group 2; and oral tongue in group 3) and analyzed. Percent discrepancies grouped by stages T1/T2 or T3/T4 were compared. Results: The mean discrepancy for all patients was a statistically significant 59.02% (P <.0001). The mean discrepancy was 71.90% for group 1, 53.33% for group 2, and 42.14% for group 3 (P =.0133). The mean discrepancy in T1/T2 tumors was 51.48% and in T3/T4 tumors was 75.00% (P =.0264). Conclusions: Oral SCC margin discrepancies after resection and specimen processing are highly significant. Tumors located in the buccal mucosa, retromolar trigone, and mandibular alveolar ridge show significantly greater discrepancies than tumors of the maxilla or oral tongue. Late stage tumors also show significantly greater margin discrepancies. These findings suggest that it might be prudent to consider oral site and staging when outlining margins to ensure adequacy of resection. (c) 2008 American Association of Oral and Maxillofacial Surgeons.