Pathological Examination in Pilonidal Sinus Surgery: Evaluating Necessity and Cost-Effectiveness: A 10-Year Retrospective Analysis.

Background: Malignancy in pilonidal sinus disease (PSD) is rare, with squamous cell carcinoma (SCC) being the most common type. This study aims to assess the incidence of malignancy in PSD and identify risk factors to guide more targeted pathological examination strategies.

Methods: A retrospective analysis was conducted on 1505 patients who underwent surgical excision of PSD between January 1, 2014, and December 31, 2023. Patients with incomplete or missing histopathological data were excluded, and no imputation methods were used for missing data. All specimens underwent histopathological examination to detect malignancies.

Results: Two cases (0.13%) of SCC were identified, both in males aged 50 and 58 years without a history of Crohn's disease, HIV, prior radiation, or other cancers. Significant risk factors for malignancy included age over 40 years (OR 3.2, 95% CI 1.1-9.5) and disease duration over 3 years (OR 2.8, 95% CI 1.0-7.6). Both cases were treated surgically and received adjuvant radiotherapy, with both patients being disease-free at the 2-year follow-up.

Conclusion: While malignancy in PSD is rare (0.13%), older age and prolonged disease duration are associated with increased risk. Selective pathological examination based on these risk factors could enhance cost-effectiveness by reducing unnecessary routine examinations.