Aggressive angiomyxoma (AA) is an uncommon mesenchymal tumour that is principally located in the soft tissues of the pelvis and perineum of young women. The primary features of this benign tumour are a local invasion, a high local recurrence rate and non-specific local clinical signs. We describe the case of a 58-year-old woman, initially treated for a Bartholin's cyst. Histological examination indicated the presence of an AA. The MRI showed a 7 cm soft tissue mass extending from the lateral wall of the vagina, into the left buttock and down into the subcutaneous tissue. We performed a radical excision with wide resection, which is considered the standard gold treatment.