Musculoskeletal tuberculosis constitutes nearly 35% of extrapulmonary tuberculosis cases and accounts for about 1–3% of the total global tuberculosis burden ^[1]. The most frequently affected joints, in descending order, are the spine, hip, and knee. Tuberculous arthritis of the elbow joint is exceedingly uncommon, comprising only 1–5% of musculoskeletal tuberculosis presentations ^[1]. Chronic synovial inflammation accompanied by hypertrophy may, on occasion, produce rice bodies ^[2]. Rice body tenosynovitis represents an infrequent clinical entity linked to diverse causes such as rheumatoid arthritis and tuberculosis. If neglected, the presence of multiple rice bodies may exert mass effect, with potential neurovascular compromise or even secondary osteoporosis in adjacent osseous structures ^[3].

A 70-year-old female presented with an insidiously developing swelling over the anterior aspect of the left elbow, which gradually increased and led to progressive limitation of movement. On examination, a firm, cystic, and immobile mass measuring approximately 3 × 4 cm was detected on the anterolateral elbow, associated with severe restriction of joint motion (fixed flexion deformity with range 40°–90°) (Fig. 1).

Figure 1: Firm swelling over the anterior aspect of the left elbow, causing limitation of movement.

Neurovascular examination was unremarkable. Plain radiographs demonstrated advanced joint destruction (Martini-Stage 4) (Fig. 2) ^[4].

Figure 2: Plain radiographs demonstrated advanced joint destruction (Martini-Stage 4).

Magnetic resonance imaging (MRI) revealed an ill-defined lobulated lesion measuring 10 × 9 × 6 cm involving the synovium, intra-articular and periarticular tissues of the postero-lateral elbow, producing erosions of the distal humerus and proximal radius and ulna, with distortion of joint alignment, radiologically mimicking synovial chondromatosis (Fig. 3).

Figure 3: Magnetic resonance imaging revealed an ill-defined lobulated lesion measuring 10 × 9 × 6 cm involving the synovium, intra-articular, and periarticular tissues of the postero-lateral elbow.

Sputum smear for acid-fast bacilli and culture were negative. Core-needle biopsy yielded non-diagnostic results. Total synovectomy was performed, revealing a dislocated elbow joint with intact ligaments. Upon synovium incision, numerous glistening, friable rice bodies were found and excised en bloc. Thorough debridement of the joint was carried out, following which the limb was managed conservatively with an above-elbow immobilization cast for 6 weeks (Fig. 4).

Figure 4: Synovectomy showing numerous glistening, friable rice bodies.

Histopathological examination confirmed chronic granulomatous inflammation with caseous necrosis and multinucleated giant cells, consistent with tuberculosis (Fig. 5).

Figure 5: Low-power view of histopathological section demonstrating chronic granulomatous inflammation with caseous necrosis and multinucleated giant cells.

Postoperatively, with anti-tuberculous therapy (ATT) and physiotherapy, the deformity was corrected, and functional motion was regained, maintaining a range of 10°–100° by 8 weeks. The patient was followed up clinically for a period of 6 months, during which she maintained a stable functional range of motion (10°–100°) with clinical resolution of the infection and no evidence of recurrence. Further long-term follow-up was not possible as the patient expired due to an unrelated natural cause.

Skeletal tuberculosis develops from a latent pulmonary or extra-osseous source through hematogenous, lymphatic, or occasionally direct spread. In elbow tuberculosis, the olecranon and distal humerus are most often affected, while primary synovial involvement is rare ^[5]. Diagnostic challenges frequently arise because symptoms overlap with more common disorders such as rheumatoid arthritis, chronic pyogenic arthritis of low virulence, gout, pigmented villonodular synovitis, or even neoplastic lesions ^[6]. Rice bodies, initially described in 1895, are intra-articular particles resembling grains of rice ^[7]. Their exact pathogenesis remains controversial. They are thought to arise from chronic inflammation with features of osteomyelitis and arthritis ^[6]. The process begins with synovial inflammation and granulation tissue proliferation, leading to effusion and fibrin deposition, which eventually organizes into rice bodies. Cheung et al. demonstrated their protein composition resembled synovium, while Berg et al. described microvasculature within certain rice bodies ^[8,9]. While many originate intra-synovially, extra-articular rice bodies have also been reported, implying a non-synovial source. They are associated with chronic inflammatory conditions such as both seropositive and seronegative rheumatoid arthritis, osteoarthritis, and juvenile arthritis ^[10]. Rice bodies in extrapulmonary tuberculosis have been documented and are often slightly larger compared to those in autoimmune disorders. Eventually, pannus formation causes cartilage destruction, bone rarefaction, and caseous necrosis, though joint space may remain preserved for a considerable duration, influencing clinical outcomes ^[6]. Patients with elbow tuberculosis usually complain of pain, swelling, and stiffness, sometimes with localized warmth. Constitutional symptoms such as fever, malaise, and weight loss are infrequent. Because clinical features are non-specific, the disease often masquerades as other inflammatory or septic arthritis ^[11,12]. Delay in diagnosis can thus result in progressive and potentially irreversible joint destruction. Radiographic findings may demonstrate Phemister’s triad, characterized by juxta-articular osteopenia, marginal erosions, and progressive narrowing of the joint space ^[13]. Martini et al. categorized the radiological evolution of osteoarticular tuberculosis into four grades: Stage 1 – localized osteoporosis; Stage 2 – erosions or cavities in bone; Stage 3 – diffuse joint involvement without major destruction; Stage 4 – gross joint destruction ^[4]. MRI provides the most sensitive characterization. Rice bodies appear as uniformly hypointense loose bodies across sequences, with low signal intensity on T2 and proton-density weighted images. In contrast, synovial chondromatosis manifests as hyperintense nodules on T2-weighted images, assisting in differentiation ^[14]. Confirmatory diagnosis relies on biopsy with demonstration of caseating granulomas or culture positivity for Mycobacterium tuberculosis ^[1]. Management of rice body synovitis lacks standardized protocols. Conservative approaches are not endorsed in current literature ^[15]. Standard recommendations advocate a 9-month course of anti- ATT: An intensive 2-month phase with isoniazid (INH), rifampicin (RMP), pyrazinamide, and ethambutol, followed by a 7-month continuation phase with INH and RMP ^[16]. Early treatment combined with mobilization ensures favorable functional results ^[1]. Rice body excision is generally considered in symptomatic cases. Advanced peripheral joint tuberculosis can be addressed successfully with synovectomy, debridement, and abscess drainage, often obviating the need for arthrodesis ^[5]. However, studies report recurrence rates up to 60% when surgical intervention was undertaken without concurrent chemotherapy ^[17]. Hence, optimal outcomes require both prompt pharmacological therapy and appropriate surgical management when indicated. Surgical goals should prioritize joint preservation and function, as medical therapy primarily focuses on eradicating the infection.

Tuberculous arthritis of the elbow with rice body formation is rare and often mimics rheumatoid arthritis, synovial chondromatosis, or chronic septic arthritis, delaying diagnosis and causing joint damage. In our patient, definitive diagnosis was confirmed only after synovectomy and demonstration of caseating granulomatous inflammation in histopathological examination. Surgical removal of rice bodies, combined with anti-tubercular therapy and physiotherapy, restored functional mobility. This case highlights the need to consider tuberculosis in atypical elbow lesions and underscores the importance of combined surgical and medical management.

Elbow tuberculosis with rice body formation is an uncommon but important differential in chronic painless swelling and stiffness of the joint. Non-specific imaging may mimic synovial chondromatosis or inflammatory arthritis, delaying diagnosis. Early synovectomy with histopathological confirmation, followed by appropriate anti-tubercular therapy and physiotherapy, is crucial to restore function and prevent permanent joint destruction outcomes.