Histopathological study of fistula in ano and its relevance

Introduction: Fistula in ano is disease present and documented since time immemorial but still there is no clear understanding about its pathogenesis. Many clinicopathological studies have been published. Though fistulectomy specimens are common surgical specimens received in any pathology department, there are not many studies with regard to histolopathological findings. This study was undertaken to examine the histological appearance of fistulous tract and its relevance when specific etiology was diagnosed by histopathological examination. Materials and Methods: A total of 183 fistulectomy specimens received over period of two years, for histopathological examination were included in this study. Paediatric cases were excluded. Observation: Most cases were in age group of 30-40 yrs (44.2%) with male preponderance. The most common histological finding was chronic non specific inflammation of the tract. Granulomatous inflammation with caseation necrosis seen in 12.56% of cases. Non caseating granuloma was seen in 4.9% alerting the clinicians to evaluate patient for a Crohns disease. None of the cases showed malignant transformation or presence of fungi, parasites. Conclusion: Fistula in ano occurs commonly in middle age group and men more affected than women. Histopathological diagnosis is relevant to differentiate chronic nonspecific inflammation from other fistulous tract with specific etiologies like presence of granulomatous inflammation due to tuberculosis and Crohns disease. Histopathological study is also important as not to miss any malignancy presenting as fistula in ano or rare malignant transformation in long standing case. We conclude that histopathological study of excised fistula in ano is useful in further management of patients ost fistulectomy. We recommend strongly all cases of fistulectomies done for fistula in ano to be submitted for histolopathological examination.