[Mucinous adenocarcinoma on chronic perianal fistula treated by neoadjuvant QT-RT neoadyuvante and laparoscopic abdomino-perineal resection].

A 62-year-old patient, operated in the last 30 years in three occasions for perianal fistula. In June of 2004 is seen in our Service by presenting perianal fistula with abscess formation, inflammation and fever. He was explored surgically, being obtained scarce quantity of purulent material and, given the ligneous characteristic of the abscess, samples for pathology examination were obtained that were reported as mucinous adenocarcinoma. Colonoscopy showed two tubulowillous polyps, one of 6 cm of diameter and another of 1 cm located at 12 and 19 cm. from anal margin, respectively. Helicoid thoraco-abdominal-pelvic CT scan showed a perineal mass of 5 x 4 cm (Fig. 1), as well as the polyp situated to 12 cm without evidence of lymph node enlargement neither distant metastasis findings what was confirmed by the RMN . With the diagnosis of mucinous adenocarcinoma of perianal fistula or perianal extension of rectal adenocarcinoma, neoadyuvant chemotherapy was proposed along with radiation therapy of long cycle during 5 weeks and radical surgery thereafter. RT on the pelvis, including tumor with photons –6 MV– and on four isocentric fields complied with Pb to a total dose of 45 Gy in five weeks was administered. The same day chemotherapythe with 5 FU and leucovorín was initiated, cycle that was repeated during the last week of RT. Tumor responded, being reduced its size by 50%. On August 31, 2004 an abdomino-perineal laparoscopic assisted resection was done. Postoperative period was uneventful. Pathology report was of colloid mucinous adenocarcinoma without lymph node involvement and two adenomas tubulo-villous, the major of them with severe displasia serious (Fig. 2). Patient is free of disease so far in controls.