Intestinal Submucosal Mucinosis in a Patient With Systemic Lupus Erythematosus: A Case Report

Systemic lupus erythematosus (SLE) is an autoimmune disease with various clinical presentations. Mucin deposition is a characteristic finding in skin lesions, but it is rare in other organs. We present a case with erythematous patches from the terminal ileum to the anus in an SLE patient. Diffuse colitis was diagnosed clinically. However, in addition to inflammatory cell infiltration, there was abundant mucinous material deposition in the submucosa. The mucinous material was positive for Alcian blue staining (pH 2.5) and was sensitive to hyaluronidase digestion. These findings are similar to those of cutaneous mucinosis in SLE patients. This is thought to be the first case of gastrointestinal tract mucinosis in SLE reported in the literature.