When intestinal ulceration meets hematologic malignancies: clinical features and mortality from a pooled individual-patient data systematic review.

Background and aims: Intestinal ulceration with pancytopenia is rare but associated with high mortality, reported mostly in small case series. It often occurs in patients with inflammatory bowel disease (IBD) or intestinal Behçet's disease (BD) and concurrent myelodysplastic syndrome (MDS) or aplastic anemia (AA). We performed a systematic review and pooled individual-patient data analysis to characterize the clinical features, evaluate mortality, and explore prognostic factors. Methods: We searched PubMed, Embase, ClinicalTrials.gov, and PROSPERO from database inception to November 10, 2025, for eligible case reports, case series, and cohort studies. Individual patient data were extracted and pooled to describe clinical features and evaluate mortality. Cox proportional hazards models were used to assess factors associated with mortality. Results: Sixty studies (128 patients) were included. In patients with BD and MDS, a marked female predominance (68.9%) and a high prevalence of trisomy 8 (85.7%) were observed, with ulcers predominantly located in the ileocecal region. In IBD-associated cases, patients with pancytopenia were characterized by a strong male preponderance (up to 90%) and rare trisomy 8 abnormalities; intestinal involvement typically manifested as ileal ulcers in Crohn's disease (CD) and pancolitis in ulcerative colitis (UC). Diagnoses were frequently concurrent, or intestinal symptoms preceded the onset of hematologic disease. Overall mortality was substantial, ranging from 31.3% to 44.4%. In subgroup analyses, male sex and MDS evolution were associated with higher mortality in patients with BD and MDS, while high-risk MDS subtypes were linked to poorer survival in those with IBD and MDS. Conclusion: The coexistence of intestinal ulcers and pancytopenia is associated with substantial mortality, reaching as high as 44.4%. The observed sex distribution and trisomy 8 patterns should be interpreted as hypothesis-generating clinical clues rather than definitive evidence of pathogenic significance or diagnostic utility. By systematically characterizing the clinical features and prognosis of this rare condition, this study provides a useful synthesis of the available evidence and highlights priorities for future prospective and mechanistic studies. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020165205, identifier CRD42020165205.