Your case is a case of acute perianal abscess with fistula in ano....the biopsy of excised fistula tract is normal that is no tuberculosis or malignancy. So need motto worry about biopsy report
Next Steps
take good care of wound with daily dressings regular follow up with your surgeon as fistula has high chances of recurrence. plenty of liquids orally and high fiber diet to avoid constipation
Health Tips
keep monitoring the wound discharge if any