A 71-year-old man was admitted in our structure for perianal discharge. No past medical history was reported. The patient reported no tobacco, alcohol, or illicit drugs intake. His past surgical history included a precedent undocumented surgery of anal fistula over 20 years ago, to which the patient supposedly underwent incision and drainage, according to history assessment. Evolution was uneventful until October 2019 where the patient was treated twice for recurrent anal abscess fistulae at an interval of one month. Twenty-five days later the patient was admitted to our department for non-healing anal fistula. The patient reported upon admission persistent foul-smelling anal discharge with no hematochezia, no blood spotting, and no pain. Rectal examination at supine position showed an ulcerative growth measuring 1x2cm at the medio-superior quadrant on a radius of 2cm from the anal verge. Clinical examination assessed a healed scar from a fistulous path at the left inferior quadrant (Figure 1.A).
Digital rectal examination showed no growth in the anorectum with a lax anal opening and no inguinal or any generalized lymphadenopathy. The remainder of the examination was standard. Pelvic MRI showed a left perianal abscess creating a complex anal fistula attaining the scrotum, the ischia fossa, and the levator ani muscle.
Biopsy examination confirmed diagnosis of anal mucinous adenocarcinoma with coexisting epithelioid granuloma with caseous necrosis consistent with anal tuberculosis. Pulmonary active tuberculosis was ruled out through TB-biological tests. HIV infection and immunodeficiency state was ruled out as well. Thoraco-abdominal-pelvic CT scan did not demonstrate distal metastasis. Consequent to multidisciplinary deliberation, adjuvant anti-bacillary chemotherapy and long-course chemo-radiotherapy was started. Adjuvant anti-bacillary chemotherapy was initiated 1 month prior to radio-chemotherapy. Surveillance of hepatic liver functions was carried along the treatment course, and the radio-chemotherapy protocol included a total of 50 Gry fractioned over five weeks. The patient was re-admitted at the 6th week following the last dose of radio-chemotherapy aiming to re-evaluate clinically and complete the therapeutic protocol. Latter clinical examination assessed scars of previous peri-anal ulcerative lesions and peri-anal fistulae, and painful digital rectal exam with persistent left abscess (Figure 1.B). The second pelvic MRI showed discreet hemi circumferential focal anal thickening, persistent though reduced perianal abscess, and persistent complex anal fistula attaining the inter-sphincter space (Figure 2).
Decision was made for abdominal perineal resection (APR). Post-operative evolution was uneventful. The patient was discharged on day 10, after completion of hospice-training of surgical wound care, by both the patient and its caretakers including family. Short-term evaluation one month later was satisfying. Further multidisciplinary discussions ruled unnecessary to prescribe adjuvant chemotherapy based on a satisfactory result of operative specimen histology. On long-term evaluation at 6 months, the patient reported absence of symptoms with weight gain with satisfactory wound healing (Figure 3).