Tubercular synovitis mimicking rheumatoid nodules.

Area of Science:

• Rheumatology
• Infectious Diseases
• Radiology

Background:

• Tubercular tenosynovitis is an uncommon condition, typically affecting the upper limb.
• Systemic Lupus Erythematosus (SLE) can present with various musculoskeletal manifestations.
• Differentiating between infectious and autoimmune causes of synovitis is clinically important.

Observation:

• A patient with SLE presented with wrist swelling, initially suspected to be rheumatoid nodules.
• Radiographic findings showed calcification and erosive changes, primarily at the radio-carpal joint, with metacarpal joint sparing.
• Ultrasound revealed a nodule with solid and fluid components, and hyperechoic foci consistent with 'matted rice bodies' within thickened synovium.

Findings:

• The clinical and imaging findings suggested chronic synovitis of tuberculous origin, rather than rheumatoid nodules.
• Ultrasound characteristics, including 'matted rice bodies,' were key in identifying tuberculous tenosynovitis.
• The case highlights the diagnostic challenge in distinguishing between autoimmune and infectious arthropathies.

Implications:

• Ultrasound is a valuable tool for characterizing nodular swellings in patients with arthropathies.
• Early and accurate diagnosis of tubercular tenosynovitis is essential for appropriate treatment and preventing joint damage.
• This case underscores the importance of considering uncommon infections in patients with autoimmune diseases presenting with atypical symptoms.