Preoperative magnetic resonance imaging findings and intraoperative tumor invasion as risk factors for recurrence of Tenosynovial giant cell tumors of the fingers.

BACKGROUND: Tenosynovial giant cell tumors (TSGCTs) of the fingers have a relatively high recurrence rate. However, no previous studies have examined preoperative magnetic resonance imaging (MRI) data as predictors of recurrence. This study aimed to identify preoperative MRI findings and intraoperative tumor invasion patterns associated with recurrence of TSGCTs of the fingers. METHODS: We retrospectively analyzed 51 patients with TSGCTs of the fingers, who underwent preoperative MRI and surgery. Preoperative MRI parameters included tumor morphology and extent around the phalanx and tendon. Intraoperative findings included Al-Qattan classification and assessment of the neurovascular bundle, bone, joint, and tendon sheath invasion. Preoperative and intraoperative findings were compared between recurrent and non-recurrent groups. RESULTS: Recurrence occurred in six patients (11.8%). The recurrent group showed significantly higher tumor extent around the tendon (82.7 [45.8-100.0] vs. 44.8 [33.4-60.0], p = 0.04), more Al-Qattan Type II cases (66.7% vs. 22.2%, p = 0.04), and more neurovascular bundle invasion (33.3% vs. 2.2%, p = 0.03) than did those of the non-recurrent group. The four recurrent cases without neurovascular bundle invasion exhibited casting mold morphology and tumor infiltration into the deep surface of the tendon. CONCLUSIONS: Tumor extent around the tendon on preoperative MRI was greater in recurrent cases. Casting mold morphology, in cases without neurovascular bundle invasion, may indicate recurrence risk.