Definition: Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.
Input: Abstract: A 15-year-old girl presented with a very large desmoid tumour in her buttock; it extended into the pelvis and thigh and would have required hindquarter amputation for its removal. This was not performed and the tumour underwent spontaneous regression. Fourteen years later the patient is alive and well. The suggestion is made that in some cases a more expectant approach to treatment might be justified for what is essentially a non-malignant condition.

Spontaneous regression of a desmoid tumour.