Peritoneal keratin granuloma associated with endometrioid adenocarcinoma of the uterine corpus

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7119869525769574 webcite.Peritoneal keratin granuloma has been described in cases of endometrioid adenocarcinoma with squamous differentiation of the uterus, ovary and atypical polypoid adenomyoma, although the number is limited [1-9]. These cases may resemble tumor implants grossly and microscopically, and most cases have been described as keratin granulomas without viable tumor cells. Keratin granulomas without viable cancer cells do not show any significant prognostic influence, although the number of cases is limited and the follow-up period is short [2]. In only rare cases, viable adenocarcinomatous cells are found in keratin granulomas [2,6]; however, the treatment in such cases is not established. Here, we report a case of peritoneal keratin granuloma with endometrioid adenocarcinoma of the uterine corpus and review the literature.A 69-year-old Japanese woman with no previous medical history presented with postmenopausal bleeding. Her first period started at the age of 16, and stopped at the age of 50. She was gravida 2, para 2 (both of them were vaginal deliveries). Cytology and biopsy of the endometrium were obtained, which revealed endometrioid adenocarcinoma. Laboratory data showed no abnormal findings except for the elevation of CA125 (138.2 U/mL, normal < 35.0 U/mL). Total abdominal hysterectomy, bilateral salpingo-oophorectomy, lymph nodes dissection as well as the biopsy of the greater omentum were performed. Atypical cells were noted in the intraoperative cytology of the peritoneal washing (Figure 1). In addition, peritoneal nodules suspicious for dissemination were found. However, it turned out to be granulation tissue with proliferating mesothelial cells in the intraoperative frozen section as well as its permanent section.Grossly, the uterine corpus showed a papillary mass measuring 8 cm in greatest diameter. Bilateral ovaries, fallopian tubes an