Mast cell deposition and activation may be a new explanation for epiploic appendagitis.

Epiploic appendagitis is as an acute painful condition of the fat on the outside of the intestine. Thus far, there have been no publications to our knowledge that appendagitis can be caused by mast cells or can be associated with chronic pain. A patient with multisystemic disorders suffered with both chronic and acute attacks of abdominal pain for a year. The worst attack led to surgical resection of an enlarged sigmoid colon epiploic appendage. Careful review of her complex medical history and mast cell stains of gastrointestinal biopsies led to the diagnosis of mast cell activation syndrome. Re-examination of the resected appendage using an immunohistochemical stain demonstrated a high mast cell density which is a new histopathological finding. Treatment of mast cell activation syndrome and other related syndromes led to marked improvement in her health, including all types of chronic abdominal pain.