Giant Cell Tumor of the Tendon Sheath: The Most Common Hand Tumor You’ve Never Heard Of

You’ve noticed a firm, painless lump on your finger or hand that’s been slowly growing over months or years. It doesn’t hurt, but it’s getting bigger and now interferes with gripping or bending the finger. The most likely diagnosis? A giant cell tumor of the tendon sheath (GCTTS)—the second most common hand tumor after ganglion cysts.

What Is a Giant Cell Tumor of the Tendon Sheath?

Also known as pigmented villonodular synovitis (PVNS) of the tendon sheath, this is a benign (non-cancerous) tumor that arises from the synovial lining of tendon sheaths or joints. It typically presents as a firm, well-defined, slow-growing mass on the palmar surface of the finger. The tumors are lobulated, often multicolored (yellow-brown due to hemosiderin deposits), and are attached to the tendon sheath.

Who Gets Them?

• Most common in adults ages 30–50

• Women are affected slightly more often than men

• The index and middle fingers are most frequently involved

• The cause is unknown—there is no known link to occupation or trauma

Symptoms

• A firm, painless lump on the finger, usually on the palm side

• Slow, steady growth over months to years

• Difficulty bending the finger as the tumor enlarges

• Occasionally mild discomfort with direct pressure or gripping

  In some cases, the tumor can erode into bone (visible on X-ray as a scalloped defect)

Diagnosis

I can usually suspect the diagnosis based on physical examination—the firm, well-defined nature and typical location are characteristic. X-rays may show soft tissue swelling or bone erosion. MRI provides detailed information about the tumor’s extent and relationship to surrounding structures, which is helpful for surgical planning. The definitive diagnosis is confirmed by pathology after excision.

Treatment: Surgical Excision

The treatment for GCTTS is surgical removal (marginal excision). The goal is to remove the entire tumor along with any extensions or satellite nodules to minimize recurrence. The surgery is outpatient, performed under local or regional anesthesia. I use magnification to carefully dissect the tumor from the tendon, neurovascular bundles, and surrounding tissue.

The recurrence rate is approximately 10–30%, depending on how completely the tumor was removed. Recurrence is managed with re-excision.

Recovery

• Days 1–7: Soft dressing, finger motion encouraged

• Days 10–14: Sutures removed

• Weeks 2–4: Return to normal activities

Frequently Asked Questions

Is this tumor cancerous?

No. Giant cell tumors of the tendon sheath are benign. Malignant transformation is exceedingly rare.

What if it comes back?

Recurrence is managed with re-excision. Recurrent tumors behave the same as the original—benign and slow-growing.

Hand Tumor Evaluation in Phoenix

Any lump on your hand or finger that’s growing deserves evaluation. Most hand tumors are benign, but getting a proper diagnosis provides peace of mind and guides treatment. I see patients from across the Phoenix metro—Scottsdale, Mesa, Chandler, Gilbert, and the surrounding areas.

☎ Schedule Your Consultation

Call (602) 258-4788 or visit toddrichardsmd.com to book an appointment with Dr. Todd Richards. Most insurance plans accepted. Same-week appointments often available.