Elevated CA-125 in IgG4 mesenteritis: a red herring or a disease biomarker? Case report and literature review.

Mesenteric panniculitis (MP) is a rare chronic disease characterized by inflammation and subsequently fibrosis of adipose tissue of the omentum. Only recently it has been associated with IgG4-related disease. Cancer antigen 125 (CA-125) is a high-molecular mass glycoprotein, traditionally associated with ovarian cancer, although it can be elevated in other conditions. Herein we describe a case of a 56-year-old man with IgG4 related mesenteric panniculitis associated with very high levels of CA-125 at the onset of disease. The CA-125 levels corresponded to clinical disease activity and improved with steroid therapy and rituximab. A literature review was performed concerning possible association of MP, IgG4-related disease and CA-125. The review of literature suggests that high levels of CA-125 can be raised in non-malignant, inflammatory conditions including IgG4-related mesenteritis and can improve with treatment.