Rice body synovitis in children: a retrospective study of 6 cases and a systematic literature review of the last two decades (2006-2026).

OBJECTIVE

Rice body synovitis (RBS), historically linked to tuberculosis, is increasingly recognized as an articular manifestation of autoimmune diseases in children, particularly Juvenile Idiopathic Arthritis (JIA). However, its diagnosis remains challenging and its management often fragmented between rheumatology and orthopedics. This study aims to characterize RBS within the spectrum of pediatric rheumatic disease and propose an integrated management framework.

METHODS

We conducted a retrospective analysis of six pediatric patients (aged 2-9 years) with knee RBS, all of whom underwent arthroscopic debridement. Concurrently, a systematic literature review (2006-2026) was performed to synthesize global evidence on etiology, diagnosis, and treatment. Descriptive statistics were utilized to analyze the pooled cohort.

RESULTS

In our cohort, RBS was associated with JIA (n = 1), tuberculosis (n = 1), and non-specific synovitis (n = 4). Magnetic resonance imaging (MRI) demonstrated high diagnostic specificity, showing characteristic hypointense "rice bodies" within hyperintense effusion on T2-weighted sequences. Surgical debridement provided immediate symptom relief, but recurrence occurred in the JIA patient, necessitating a combination of standard and biologic disease-modifying antirheumatic therapy (DMARD). Integrating literature data yielded a pooled cohort of 44 patients, confirming JIA as the predominant etiology (77.3%) in contemporary practice, highlighting an emerging trend moving away from strictly infectious to autoimmune origins.

CONCLUSIONS

RBS represents a rare but clinically significant articular phenotype within pediatric rheumatology, most commonly linked to JIA. Successful management requires a dual strategy: (1) MRI-guided early diagnosis and (2) a collaborative rheumatology-orthopedics approach combining arthroscopic intervention with targeted immunomodulatory therapy. Critically, the interpretation of etiology must be contextualized by geographical variability; while JIA predominates in developed nations, mycobacterial infections remain a paramount diagnostic priority in tuberculosis-endemic regions.