Pleomorphic hyalinizing angiectatic tumours are rare stromal lesions histologically resembling both neurilemoma and malignant fibrous histiocytoma and occurring in the subcutaneous soft tissue of the lower and upper limbs and, less frequently, in the chest wall. The case reported here is one of 22 cases published in the medical literature and describes a pleomorphic hyalinizing angiectatic tumour which was localized in a body cavity and developed in the pelvis. The present report is the first of its kind to date. A 53-year-old asymptomatic woman was treated via an open laparotomy. The lesion arising from the left mesorectal tissue was entirely resected. The postoperative course was uneventful and the patient was discharged on postoperative day 3. The patient is still disease-free 58 months after the operation. A review of the literature shows that pleomorphic hyalinizing angiectatic tumours are locally aggressive. A 20% recurrence rate has also been observed in long-term follow-up. These patients should therefore be treated by wide local excision and require long-term surveillance.