Although fistula-in-ano was one of the earliest diseases to affect mankind, its association with carcinoma was not reported in the medical literature until the early part of this century. This association may manifest itself in several ways: (1) a fistula may be associated with cancer elsewhere in the colon; (2) cancer, either primary or recurrent, may present as a fistula; or (3) cancer may develop in a fistula-in-ano. This paper concerns the third situation.
The development of cancer in fistulous tracts or draining sinuses has not been limited to fistula-in-ano. McAnally and Dockerty reported nine cases of carcinoma in sinuses of chronic osteomyelitis and one in a chronic empyema tract. Gillis and Lee described 34 cases in which carcinoma appeared at the site of war wounds sustained 18 to 31 years previously. A squamous-cell carcinoma arising in a pilonidal sinus which had been present for 20 years was reported by