Xanthogranulomatous inflammation of the 1 perimetrium with infiltration into the uterine 2 myometrium in a postmenopausal woman : a 3 case report

29 Background: Xanthogranulomatous inflammation is an uncommon form of chronic 30 inflammation that is destructive to the normal tissue of affected organs. Although 31 xanthogranulomatous endometritis and xanthogranulomatous salpingitis of the female 32 genital tract has been described previously, to the best of our knowledge, this is the first 33 report of xanthogranulomatous inflammation with infiltration into the uterine 34 myometrium from the perimetrium without endometritis. 35 Case presentation: A 68-year-old Japanese woman with intermittent lower abdominal 36 pain and low-grade fever who was initially treated with antibiotics underwent 37 hysterectomy due to abscess formation in the posterior wall of the myometrium and 38 perimetrium (the outer serosal layer of the uterus). Histopathological findings revealed 39 that the abscess was caused by xanthogranulomatous inflammation with the granulation 40 tissue and chronic inflammatory cells that consisted of focal and sheets of foam cells. The 41 inflammation destroyed the perimetrial elastic lamina, and the myometrium was deeply 42 infiltrated by the xantohma cells. Neither endometritis nor salpingitis was coexistent with 43 the xanthogranulomatous inflammation. 44 Conclusion: The patient was diagnosed as xanthogranulomatous inflammation, most 45 likely arising from the perimetrium. Our findings suggest that the perimetrium, as well as 46 the endometrium and adnexae, is one of the origins of xanthogranulomatous 47