[Clinicopathologic characteristics of pseudomyxoma peritonei].

Objective: To analyze the relationship between clinicopathologic characteristics of pseudomyxoma peritonei (PMP) and its prognosis. Methods: Fifty-two cases of PMP collected from 2012 to 2017 at Beijing Shijitan Hospital, Capital Medical University were reviewed using the diagnostic criteria of WHO 2010. The histopathologic features, including original location, neural invasion and calcification were observed; and the relationship with prognosis was analyzed. Immunohistochemical staining for CK7, CK20 and CDX2 was performed on all cases. ER, PR, and p16 were additionally performed on those without clear origin. Results: Patients' mean age was 52.0 years, and included 29 males and 23 females. Thirty-two cases were derived from appendix; among them, 23 were low grade and 29 were high grade. Signet ring-cells, neural invasion and calcification were detected in 15, 12 and 9 cases respectively. Neural invasion was associated with adverse prognosis (P=0.025) and signet ring cell morphology (P<0.01). Prognosis was not related to gender, age, original location or grade. Conclusion: Neural invasion is not uncommon in PMP and predicts a bad prognosis.