Purpose: Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue tumour first identified at the end of the 1990s. This study presents our experience and literature reviews focusing on risk of recurrence.
Methods: Rizzoli Orthopaedic Institute database and literature were searched for patients with MIFS observed from 1997 to 2012. Data were analysed in a new database.
Results: Five patients underwent surgery at our institute, and 133 cases were retrieved from the literature. Not all clinicopathological data were available: 76/138 were men (55%), median age was 45 [interquartile range (IQR) 34-56] years, median tumour size was three (IQR two to five) centimetres. Common sites of occurrence were hand (24%), fingers (23%) and foot (20%). Pain was present at diagnosis in 14/82 patients (17%), with a median duration of seven (IQR three to 12) months. Surgery was performed for a suspected benign tumour in 88 patients (74%). Resection was incomplete in 45/71 cases (63%); re-excision was performed in 32/45 (71%). At a median follow-up of 26 months, 26/118 patients (22%) developed recurrent disease; median time to recurrence was 15 months (IQR seven to 26). Actuarial relapse-free survival (RFS) at one, three and five years was 93%, 72% and 67%, respectively. At univariate analysis, only symptom duration of six months or less was significantly associated with a worse RFS (p = 0.046). Metastatic disease to lymph nodes and/or lungs was observed in four patients (3%).
Conclusions: Clinicopathological findings confirm the low-grade nature of MIFS. However, local recurrence occurs, and patients may be affected by aggressive forms with a potential for distant metastases. Follow-up is strongly advised.