The Development of Sarcoidosis in an Ulcerative Colitis Patient Treated with Vedolizumab: A Case Report and Review of the Literature

BACKGROUND: Ulcerative colitis (UC) and sarcoidosis are chronic inflammatory diseases that share immunological pathways but rarely coexist. The increasing use of biologic agents in inflammatory bowel disease (IBD) has raised concerns regarding paradoxical inflammatory manifestations, including sarcoidosis-like reactions. CASE PRESENTATION: We report the case of a 63-year-old man with long-standing UC treated with vedolizumab who developed systemic sarcoidosis characterized by bilateral hilar lymphadenopathy, mediastinal and abdominal lymph node enlargement, pulmonary involvement, and erythema nodosum. Extensive diagnostic work-up, including imaging and histopathology, confirmed non-necrotizing granulomatous disease consistent with sarcoidosis, while alternative infectious, malignant, and drug-induced causes were excluded. Vedolizumab was temporarily discontinued, leading to UC relapse, and subsequently reintroduced with rapid clinical remission of UC. DISCUSSION: Sarcoidosis remained clinically and radiologically stable despite vedolizumab re-initiation, suggesting a coincidental association rather than a direct causal relationship. This case highlights the diagnostic challenges and therapeutic dilemmas in patients with immune-mediated diseases receiving biologic therapy. CONCLUSION: The coexistence of UC and sarcoidosis during vedolizumab therapy is rare. Although causality cannot be established, our findings suggest that vedolizumab may be safely continued in selected patients under close multidisciplinary monitoring.