{"paper_id":"3c113bff-247d-4a4e-a186-63b7b15cc193","body_text":"Catamenial Appendicitis\n- Breton F. Barrier\n- Shellaine R. Frazier\n- Lisa M. Brennaman\n- Jessica C. Taylor\n- Bruce J. Ramshaw\nBACKGROUND:\nReproductive-aged women undergoing appendectomy for suspected appendicitis have twice the rate of negative histology as age-matched men. The reason for this discrepancy is unknown.\nCASES:\nThree patients with peritoneal endometriosis and recurrent symptoms of acute appendicitis coincident with menses underwent resection of a noninflamed appendix with long-term symptom resolution. Standard pathological evaluation failed to demonstrate evidence of appendiceal endometriosis or appendicitis. Additional evaluation demonstrated a marked increase in number of mast cells in the appendiceal muscularis compared with normal appendices.\nCONCLUSION:\nThe term “catamenial appendicitis” has been coined to describe these cases, and a mechanism of pathogenesis of right lower quadrant pain and nausea in patients with histologically confirmed endometriosis is proposed.","source_license":"CC0","license_restricted":false}