Primary intestinal lymphangiectasia across the lifespan: adult-pediatric comparisons of diagnostic delay, immune findings, and treatment patterns.

Background

Primary intestinal lymphangiectasia (PIL) is classically considered a pediatric lymphatic disorder, but adult presentation may be under-recognized.

Methods

We searched six databases from inception through January 31, 2026, for reports with extractable PIL data. Adult-pediatric comparisons used Mann-Whitney U and Fisher exact tests.

Results

After a source-level and eligibility audit, the evidence base comprised 128 individually abstracted primary PIL cases and two author-described pediatric cohorts reported only in aggregate (n = 28 and n = 34); both aggregate cohorts were summarized separately. Among 111 individual cases with age at diagnosis, 58 (52.3%) were adults and 53 (47.7%) were pediatric. Median diagnostic delay was 4.00 years in adults (IQR, 1.00-15.00; n = 30) and 2.21 years in pediatric cases (IQR, 0.69-6.56; n = 30; p = 0.135); delays of at least 10 years occurred in 10/30 (33.3%) and 3/30 (10.0%), respectively (p = 0.057). Baseline albumin was 1.90 g/dL (IQR, 1.60-2.20; n = 93). Individually mapped objective protein-losing enteropathy testing was documented in 37/128 (28.9%), lymphocyte subsets in 20/128 (15.6%), and follow-up duration in 80/128 (62.5%). Diet and medium-chain triglycerides predominated; no estimable treatment or recurrence comparison reached nominal significance.

Conclusions

Adult PIL is well represented in published individual cases, but selective reporting and incomplete diagnostic confirmation limit inference. Structured exclusion of secondary etiologies and standardized longitudinal outcomes are needed.