Perianal fistulae are commonly complicated by abscesses and ramifications, which have well-recognized imaging morphology. Less commonly, atypical findings of solid enhancing mass-like lesions with no fluid component are associated with chronic and recurrent fistulae, the etiology of which includes inflammatory masses as well as locally aggressive malignancy. The latter predicts poorer prognosis and warrants extensive surgical resection. The reading radiologist must identify the unusual appearance, be aware of the possible etiologies, and if appropriate recommend prompt tissue sampling to exclude malignancy. This is pertinent as it determines surgical management, which is crucial in achieving a potential curative outcome.