LAUSR

Solitary fibrous tumors (SFT) are uncommon mesenchymal neoplasms which can arise at a wide variety of anatomic locations. SFT were described from the pleura firstly, but they could arise in extrathoracic sites at abdominal cavity, head and neck or retroperitoneum. Most of SFT are asymptomatic at presentation, but abdominal neoplasms can associate abdominal pain, urinary symptoms, or palpable mass. Malignant behavior is rare but possible. We present the case of 83-year-old woman with a malignant pelvic SFT who underwent surgery and later adjuvant radiotherapy, with no recurrence at 36 months follow-up. An 83-year-old woman referred to our service because of an incidental finding of a pelvic mass on abdominal ultrasonography ordered by her family physician. She only reported abdominal discomfort for several months in duration, and hypoglycemia was not present at presentation. On physical examination there was the clinical impression of a painless and palpable mass in the left iliac fossa. Laboratory tests were normal. A computed tomographic scan revealed a 7.5 cm 5.4 cm 4.2 cm pelvic mass involving intimate contact with the left wall of the bladder, being this organ laterally displaced. The mass was well-defined, solid and lobulated, with internal necrotic areas and small peripheral cystic compounds. Multiple and dilated vascular structures located inside were identified, these being connected to peripheral vessels and irrigated by iliac internal vessels (Fig. 1A and B). A contrast magnetic resonance imaging (MRI) scan (Fig. 1C and D) showed an heterogeneous solid mass with mild