CASE 139
By: Dr. Nizar Al-Nakshabandi MD, FRCPC
HISTORY: 59-year-old male with long-standing painless swelling of the distal third finger.
What are your findings?
What is the differential diagnosis?
What are the causes?
FINDINGS:
AP and lateral views of the right hand [A, B] respectively demonstrate a soft tissue swelling over the DIP of the third finger measuring 1 x 0.5 cm on the dorsal and ulnar aspect of the finger. There is an evidence of bone remodeling and erosion from long-standing effect from the lesion. Axial gradient echo image [C] demonstrates the lesion to be hypointense engulfing the tendon of the extensor pulley A 3 at the level of the DIP. Coronal T1 weighted image demonstrates the lesion once again engulfing the tendon and causing bone remodeling of the second phalanx of the third digit [D]. Coronal T1 weighted images with intravenous gadolinium with fat saturation [E] demonstrate the lesion to be mildly enhancing.
DIFFERENTIAL DIAGNOSIS:
· Giant cell tumor of the tendon sheath.
· Ganglion cyst.
· Pigmented villonodular synovitis.
· Desmoid tumor.
· Fibroma.
DIAGNOSIS: Giant cell tumor of the tendon sheath.
PEARLS AND DISCUSSION:
Giant cell tumor of the tendon sheath is a benign condition and not likely to represent a neoplasm. It is usually present in the fifth decade with a male to female ratio at 1.5:1. A mass is generally seen on the site of the swelling and is usually without pain. Long-standing history is given of a slow-growing lesion. Giant cell tumor is pathologically like pigmented villonodular synovitis and they can be localized or diffuse. The only difference is that giant cell tumor is outside the joint, whereas PVNS is inside the joint. Local surgical resection is efficient. However, recurrence can be seen in up to 20% of the cases. Metastasis has been reported to the lymph nodes and lungs although still considered a benign entity.
FURTHER READING:
1. Al-Nakshabandi N, Ryan AG, Choudar H, Al-Ismail K. Pigmented villonodular synovitis. Clinical Radiology 59(5):414-20 · June 2004.
2. Middleton WD, Patel V, Teefey SA et-al. Giant cell tumors of the tendon sheath: analysis of sonographic findings. AJR Am J Roentgenol. 2004;183 (2): 337-9.
