Tasche, K.

Background: To compare oncologic and postoperative outcomes in patients with scalp squamous cell carcinoma with periosteal, but not gross calvarial, involvement, treated with margin-clearing excision including either calvarial burring or periosteal excision alone. Study Design: Retrospective cohort study. Setting: Single tertiary academic referral center. Methods: We retrospectively reviewed surgical cases from January 2001 to January 2025. Inclusion criteria: patients ≥18 years with biopsy-proven scalp squamous cell carcinoma involving the periosteum without cortical invasion on imaging. Management of the deep margin included either burring of the outer table or periosteal excision alone. Demographic, surgical, and oncologic outcomes were collected and analyzed descriptively. Results: Twenty patients met inclusion criteria. Median age was 70 (range 56-92), and 18 (86%) were male. Thirteen (65%) patients underwent calvarial burring, 7 (35%) underwent periosteal excision. Local recurrence occurred in 31% and 29% of the burring group and non-burring group. Disease-free survival at 2 years was 46% and 57% in the burring and non-burring group, respectively. Overall survival at 2 years was 77% and 86% in the burring and non-burring group. Three patients in the burring group had local recurrences with intracranial extension, 1 died of disease, 1 died with disease and concurrent meningitis, 1 is alive with disease recurrence currently on palliative treatment. There were 7 disease-related deaths. Conclusion: Burring did not confer a significant oncologic advantage compared to periosteal excision alone when there was no gross cortical invasion. Local recurrence in patients undergoing calvarial burring was associated with intracranial extension of disease.