Rice Body Formation Due to Different Etiologies in the Distal Forearm.

Abstract

Rice body formation in the distal forearm is an exceedingly rare clinical entity, often associated with chronic synovitis of varying etiologies. This study investigates four unique cases of forearm synovitis with rice body formation, hypothesizing that diverse underlying causes-rheumatoid arthritis, trauma, and idiopathic inflammation-contribute to this condition, and that surgical intervention ensures symptom resolution and prevents recurrence. The patients (three males, one female; aged 42-76 years) presented with heterogeneous clinical manifestations, including localized swelling, nerve compression symptoms, and restricted joint mobility. Diagnostic MRI revealed characteristic features: T1-weighted isointense masses with T2-weighted high-signal foci containing punctate low signals, aiding differentiation from other synovial pathologies. All patients underwent radical synovectomy with median nerve decompression, followed by histopathological analysis. Results demonstrated chronic granulomatous synovitis without evidence of infection (negative cultures and stains for tuberculosis, fungi, and bacteria). Postoperatively, all patients achieved complete symptom relief, with no recurrence or functional deficits observed during follow-up (9-22 months). Literature review highlighted the rarity of forearm rice bodies and underscored MRI's diagnostic superiority over radiography. The cases underscore that rice body formation, while historically linked to rheumatoid arthritis or tuberculosis, can arise from nonspecific synovial inflammation or trauma. Surgical excision combined with nerve release emerged as the definitive treatment, addressing both mechanical compression and inflammatory burden. This study emphasizes the importance of considering diverse etiologies in forearm synovitis, advocating for early MRI evaluation and tailored surgical management to optimize outcomes. The findings contribute to understanding the multifactorial pathogenesis of rice bodies and reinforce the efficacy of synovectomy in preventing recurrence and restoring function.