Purpose of the study: Extra-abdominal aggressive fibromatosis (EAAF) is a benign desmoid tumor with a potentially aggressive behavior. Surgical treatment is compromised by a very high rate of recurrence, sometimes with significant morbidity. We conducted a prospective surveillance of our patients (clinical and MRI) with EAAF to search for prognostic factors.
Material and methods: This cohort included 17 patients with EAAF. For nine patients, biopsy alone was performed. For eight, the tumor was a recurrence after surgical removal. Patients were seen for a clinical assessment and MRI every six months.
Results: Median follow-up was 42 months (range 6-114). Three patients worsened clinically with pain or functional impairment. One patient required neurosurgery to control pain (good stable outcome). MRI showed progression for two tumors (12%) but with a short follow-up since diagnosis (9 and 14 months), in one case despite medical treatment. Three tumors regressed and twelve remained stable on successive MRI. On average the tumor growth lasted ten months.
Discussion: Tumor growth was never noted beyond 36 months. This notion of an interruption in tumor growth is mentioned sporadically in reports on EAAF, which have generally included recurrent tumors. To our knowledge this is the first series reporting tumors left in place a followed with modern imaging techniques. The high rate of spontaneous interruption of tumor growth must be counterbalanced with the difficult task of local treatment: the risk of recurrence is particularly high after surgery and functional sequelae can be significant when wide resection is proposed in an anatomically difficult localization. The precise role for surgery, and combined radiotherapy, remain to be determined. There are only scarce reports on general treatments. Considering these facts, we propose that surgical resection should not be considered the only solution for the treatment of EAAF. Further work is needed to define the useful contribution of simple surveillance of these benign tumors.