BACKGROUND: The WHO classification of mucinous appendix neoplasms and pseudomyxoma peritonei (PMP) describes low- and high-grade histology and is of prognostic importance. The metastatic peritoneal disease grade can occasionally be different from the primary appendix tumor. This analysis aimed to report outcomes from a high-volume center in patients with pathological discordance. METHODS: This was a retrospective analysis of prospective data of patients treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP at a single institution between January 2016 and December 2020. Reporting was by pathologists with a special interest in peritoneal malignancy. Discordant pathology was classified as a low-grade primary appendix tumor with high-grade peritoneal disease, or a high-grade primary appendix tumor with low-grade peritoneal disease. Outcomes analyzed were overall and recurrence-free survival, and Kaplan-Meier survival curves and the log-rank test were used to analyze the outcomes. RESULTS: Between 2016 and 2020, 830 patients underwent CRS and HIPEC for PMP, of whom 37 (4.4%) had discordant pathology. The primary appendix tumors were low-grade in 23 patients and high-grade in 14 patients. The median Peritoneal Cancer Index (PCI) was significantly higher in patients with a low-grade primary tumor (31 vs. 16; p = 0.001), while complete cytoreduction (CC0/1) was achieved in 31/37 (83.8%) patients. The median follow-up was 19 months. Overall survival was worse in those with high-grade peritoneal disease (p = 0.029), whereas recurrence-free survival was similar in both groups (p = 0.075). CONCLUSION: In PMP with pathological discordance, the peritoneal disease grade influences prognosis and survival.
BACKGROUND: The WHO classification of mucinous appendix neoplasms and pseudomyxoma peritonei (PMP) describes low- and high-grade histology and is of prognostic importance. The metastatic peritoneal disease grade can occasionally be different from the primary appendix tumor. This analysis aimed to report outcomes from a high-volume center in patients with pathological discordance. METHODS: This was a retrospective analysis of prospective data of patients treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP at a single institution between January 2016 and December 2020. Reporting was by pathologists with a special interest in peritoneal malignancy. Discordant pathology was classified as a low-grade primary appendix tumor with high-grade peritoneal disease, or a high-grade primary appendix tumor with low-grade peritoneal disease. Outcomes analyzed were overall and recurrence-free survival, and Kaplan-Meier survival curves and the log-rank test were used to analyze the outcomes. RESULTS: Between 2016 and 2020, 830 patients underwent CRS and HIPEC for PMP, of whom 37 (4.4%) had discordant pathology. The primary appendix tumors were low-grade in 23 patients and high-grade in 14 patients. The median Peritoneal Cancer Index (PCI) was significantly higher in patients with a low-grade primary tumor (31 vs. 16; p = 0.001), while complete cytoreduction (CC0/1) was achieved in 31/37 (83.8%) patients. The median follow-up was 19 months. Overall survival was worse in those with high-grade peritoneal disease (p = 0.029), whereas recurrence-free survival was similar in both groups (p = 0.075). CONCLUSION: In PMP with pathological discordance, the peritoneal disease grade influences prognosis and survival.
Authors: Haroon A Choudry; Reetesh K Pai; Anoosh Parimi; Heather L Jones; James F Pingpank; Steven S Ahrendt; Matthew P Holtzman; David L Bartlett Journal: Ann Surg Oncol Date: 2019-05-20 Impact factor: 5.344
Authors: Marwa Al-Azzawi; Joseph Misdraji; Marie-Louise F van Velthuysen; Jinru Shia; Melissa W Taggart; Rhonda K Yantiss; Magali Svrcek; Norman Carr Journal: J Clin Pathol Date: 2019-10-13 Impact factor: 3.411
Authors: Norman J Carr; Thomas D Cecil; Faheez Mohamed; Leslie H Sobin; Paul H Sugarbaker; Santiago González-Moreno; Panos Taflampas; Sara Chapman; Brendan J Moran Journal: Am J Surg Pathol Date: 2016-01 Impact factor: 6.394
Authors: Kim Govaerts; K Chandrakumaran; Norman J Carr; Thomas D Cecil; Sanjeev Dayal; Faheez Mohamed; Andrew Thrower; Brendan J Moran Journal: Eur J Surg Oncol Date: 2018-07-06 Impact factor: 4.424