Giant cell tumor is the most common locally aggressive bone tumor that occurs mostly at the distal femur or proximal tibia, typically involving the epiphysis of the bone [1-3]. Clinically, it presents as insidious pain at the affected site that worsens with activity. Swelling and joint stiffness may also be present [2,4]. Radiologically, the tumor typically shows a characteristic “soap bubble” appearance [3,5], and diagnosis is confirmed with biopsy postoperatively ^[5]. Intraoperatively, after excision of the bony lesion, adjuvants are used to reduce recurrence [6,7]. Bone grafting or bone cementation is performed when there is a large defect post-excision ^[6]. Postoperatively, patients are immobilized with a splint for 2–3 weeks, followed by physiotherapy. By six months, patients typically show clinical and functional improvement with full range of motion and no pain at the operated site [6-10].

A 43-year-old female presented with complaints of pain and swelling in her right wrist for 15 days following a slip and fall inside a moving bus. She initially self-medicated with NSAIDs, but the pain persisted. On examination, a solitary, tender, bony-hard swelling measuring 4×2×1 cm was noted over the ulnar aspect of the right wrist without secondary skin changes [Fig. 1]. Wrist movements were preserved except for terminal pain in ulnar deviation and dorsiflexion [Table 1]. Radiographs revealed an epiphyseal lesion with metaphyseal extension at the distal ulna, displaying a geographic lytic pattern with a narrow zone of transition, soap bubble appearance, internal trabeculations, and a possible cortical breach [Fig. 2], consistent with findings reported by Goldenberg et al. ^[3] and Schajowicz ^[8]. CT confirmed focal cortical discontinuity [Fig. 3,4], while T2-weighted MRI demonstrated fluid-fluid levels, a feature noted in prior studies by Masui et al. ^[5] and Turcotte et al. ^[6] [Fig. 3]. Based on Enneking’s staging system, the lesion was classified as Stage 2 [active], and according to Campanacci grading, it was a Grade II lesion, indicating locally aggressive behavior with cortical thinning but without soft tissue extension ^[2].

Surgical management involved wide resection using the Darrach procedure ^[14] [Fig.s 5 and 6], followed by dynamic stabilization with extensor carpi ulnaris [ECU] tenodesis to the distal ulnar stump [Fig. 7], as described by Singh et al. ^[9] and Novel and Arafa ^[15]. A frozen section was performed intraoperatively to confirm negative margins before proceeding with definitive reconstruction, ensuring complete tumor clearance ^[10]. Following excision, hydrogen peroxide was used as a local chemical adjuvant within the cavity to reduce the risk of local recurrence, consistent with methods reported in prior studies ^[7]. Postoperatively, the patient was immobilized with an above-elbow splint for 4–5 weeks, followed by progressive wrist mobilization and strengthening through physiotherapy.

Follow-up was structured in accordance with established GCT surveillance guidelines [10,11]. Clinical evaluation and local radiographs were performed every 3 months for the first two years, then every 6 months for up to 5 years to monitor for local recurrence. Chest imaging [X-ray or CT] was conducted biannually during the first two years and annually thereafter to screen for pulmonary metastasis. Functional outcomes were assessed during each visit, with focus on wrist range of motion, grip strength, and any signs of recurrence. Patients were educated about early symptoms such as return of pain, swelling, or limited joint function.

At one-year follow-up, the patient had full, pain-free wrist motion [Fig. 8-12] without any clinical or radiological evidence of recurrence [Fig. 10], consistent with outcomes reported by Ward and Li ^[10].

Giant cell tumor [GCT] of bone is a benign yet locally aggressive tumor, constituting 4–5% of all primary bone tumors, with a predilection for young adults, especially females [1,4]. The distal radius and ulna are common sites, accounting for 10–12% of cases ^[11]. These tumors originate from mesenchymal stromal cells and exhibit osteolytic destruction, cortical breach, and soft tissue extension in aggressive cases [7,12]. Radiologically, GCTs show a characteristic soap bubble appearance with a narrow zone of transition, internal trabeculations, and an expansile nature, as described by Goldenberg et al. ^[3] [Fig. 2]. MRI findings, including fluid-fluid levels, are useful in differentiating GCTs from aneurysmal bone cysts [5,6] [Fig. 3]. Enneking’s staging classifies GCTs into Stage 1 [latent], Stage 2 [active], and Stage 3 [aggressive], which influences surgical management decisions ^[2]. Similarly, Campanacci grading divides them into Grade I [latent], Grade II [active but contained within bone], and Grade III [aggressive with soft tissue extension] ^[2]. The lesion in this case was classified as Stage 2 [active] and Grade II, indicating a high risk of recurrence but without extraosseous invasion. Treatment strategies for GCTs range from intralesional curettage with adjuvant therapy to en bloc resection, depending on lesion grade and anatomical location [7,13]. Wide resection is preferred in cases involving extensive cortical breach or high recurrence risk ^[10] [Fig. 4]. The Darrach procedure, originally described for post-traumatic conditions, has been successfully adapted for tumors of the distal ulna ^[14] [Fig. 5, Fig. 6]. However, resection of the distal ulna can result in instability, necessitating reconstructive stabilization techniques. Extensor carpi ulnaris tenodesis is a well-established method to restore wrist stability post-resection, as highlighted by Singh et al. ^[9] and Novel and Arafa ^[15] [Fig. 7]. This approach allows preservation of wrist function while minimizing postoperative complications. Postoperative radiographs at two weeks [Fig. 8], six months [Fig. 9], and one year [Fig. 10] demonstrated no radioulnar convergence, confirming the efficacy of the stabilization procedure. Improvement in wrist mobility was noted at six months [Fig. 11, Table 2] and further optimized at one year [Fig. 12, Table 3].

Early recognition of GCT, particularly in patients with persistent pain and swelling post-trauma, is crucial to prevent misdiagnosis and delays in treatment. Radiological evaluation, including CT and MRI, plays a critical role in diagnosis and surgical planning. The Enneking and Campanacci grading systems provide a structured approach to assessing tumor behavior and determining appropriate treatment strategies. Surgical excision with proper stabilization, such as the Darrach procedure with ulnar tenodesis, ensures optimal functional recovery while minimizing complications. This case reinforces the importance of a tailored surgical approach in achieving successful long-term outcomes in patients with GCT of the distal ulna.

Giant cell tumors should be considered in patients with persistent wrist pain and swelling post-trauma, even in the absence of severe movement restriction. Radiological assessment, along with Enneking staging and Campanacci grading, aids in early diagnosis and treatment planning. Surgical excision with stabilization techniques like ulnar tenodesis can restore wrist function while preventing long-term instability.