Appendiceal mucinous neoplasms have been classified differently over time causing confusion when comparing results between working groups in this field and establishing a prognosis of the disease. A historical perspective of the different classification systems of these tumors is essential for the understanding of the evolution of concepts and histopathological definitions that have led up to the present moment. We carried out a systematic review of the pathological classifications of appendiceal mucinous tumors and how they have included the new criteria resulting from clinical and pathological research. The latest classifications by PSOGI and AJCC 8th edition Cancer Staging have made a great effort to incorporate the new pathological descriptions and develop prognostic groups. The introduction of these new classification systems has posed the challenge of verifying how they adapt to our casuistry and which one defines best the prognosis of our patients. We reclassified our series of patients treated for mucinous appendiceal tumors with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy following the PSOGI and the AJCC 8th edition criteria and concluded that both classifications correspond well with the OS and DFS of these patients, with some advantage relative to the PSOGI classification due to a better histopathological description of the different groups.

Alvaro Gregorio Morales Taboada, Pablo Lozano Lominchar, Lorena Martin Roman, Pilar García-Alfonso, Andres Jesús Muñoz Martin, Jose Antonio Blanco Rodriguez, and Jose Manuel Asencio Pascual. Ann Hepatobiliary Pancreat Surg 2021;25:179-91. https://doi.org/10.14701/ahbps.2021.25.2.179

Objectives The Peritoneal Surface Oncology Group International (PSOGI) consensus subdivided pseudomyxoma peritonei (PMP) into four groups according to histopathological features. The aim of this paper is to report survival outcomes after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) from a national referral centre and to correlate the PSOGI classification with survival. Methods A retrospective study of a prospectively maintained database was performed. Consecutive patients treated with CRS + HIPEC for PMP of appendiceal origin were included (September-2013 to December-2021). Pathological features of the peritoneal disease were used to classify patients into the four groups proposed by PSOGI. Survival analysis was performed to evaluate the correlation of pathology on overall survival (OS) and disease-free survival (DFS). Results Overall, 104 patients were identified; 29.6 % were reclassified as acellular mucin (AM), 43.9 % as low-grade mucinous carcinoma peritonei (LGMCP), 22.4 % as high-grade MCP (HGMCP) and 4.1 % as HGMCP with signet ring cells (HGMCP-SRC). Median PCI and rate of optimal cytoreduction were 19 and 82.7 %, respectively. Median OS and DFS were not reached, 5-year OS and DFS were 88.6(SD 0.04) % and 61.6(SD 0.06) %, respectively. Log-Rank test revealed significant differences in terms of OS and DFS across the different histological subgroups (p<0.001 in both cases). However, histology did not retain its significance in the multivariate analysis for OS or DFS (p=0.932 and p=0.872, respectively). Conclusions Survival outcomes after CRS + HIPEC for PMP are excellent. The PSOGI pathological classification correlates with OS and DFS, but differences were not significant at multivariate analysis when adjusted for other prognostic factors.

Context Hypoparathyroidism is the most frequent complication after total thyroidectomy (PT-hypoPTH). After 1 year, most patients recover parathyroid function; however, the implicated physiologic dynamics remain unknown. Vitamin D deficiency (VDD) is the main cause of secondary hyperparathyroidism. Whether this compensatory hyperparathyroidism could influence parathyroid function recovery (PFR) in the setting of PT-hypoPTH has not been studied. Objective This work aimed to evaluate the effect of preoperative VDD on PFR. Methods A retrospective study was conducted with a prospectively maintained database including patients undergoing a total thyroidectomy between May 2014 and June 2019. Preoperative vitamin D (25(OH)D) less than 20 mg/mL was defined as VDD. Intact PTH less than 14 pg/mL on postoperative day 1 was defined as PT-hypoPTH. Transient PT-hypoPTH displayed PFR within the first year (early recovery: < 30 days; protracted recovery: > 30 days) whereas definite PT-hypoPTH did not. Survival analysis evaluated the effect of preoperative VDD on PFR, and a binary logistic regression model identified associated factors. Results A total of 397 patients were identified. The observed rates of transient, protracted, and definite PT-hypoPTH were 32.9%, 15.1%, and 5.2%, respectively. Rates of VDD were higher in the early-recovery PT-hypoPTH group (55.2% vs 31.5%; P = .01). Preoperative VDD was associated with faster PFR (19 vs 35 days; P = .03) and behaved as a protective factor for protracted PT-hypoPTH (odds ratio 0.47; 95% CI, 0.25-0.881; P = .016) in the multivariable analysis. Conclusion Preoperative VDD could act as a preconditioning factor of the parathyroid glands prior to the surgical aggression exerted against them during surgery aiding PFR. Basic research studies and prospective clinical trials are needed to explain the underlying physiological mechanisms and to provide further evidence to improve clinical management.

Aims Several classification systems are used for pseudomyxoma peritonei. The four-tiered classification system proposed by Peritoneal Surface Oncology Group International (PSOGI) and the two-tiered proposed by the eighth edition of the American Joint Committee on Cancer (AJCC) result from evolution in terminology and pathological insight. The aim is to evaluate the impact of PSOGI and eighth edition of the AJCC classifications on survival. Methods Pathological slides were reviewed from a prospectively maintained database including patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for an appendiceal mucinous neoplasm with peritoneal dissemination between January 2009 and December 2019. Patients were reclassified according to PSOGI and AJCC eighth edition criteria. Survival analysis evaluated the impact of each classification system on overall survival (OS) and disease-free survival (DFS) while the concordance-index evaluated their predictive power. Results 95 patients were identified; 21.1% were reclassified as acellular mucin, 55.8% as low-grade mucinous carcinoma peritonei, 8.4% as high-grade MCP (HGMCP) and 14 as HGMCP with signet ring cells. Median OS was not reached, 5-year OS and DFS were 86.1% and 51.5%, respectively. Multivariate analysis revealed significant associations with OS (PSOGI: HR 10.2, p=0.039; AJCC: HR 7.7, p=0.002) and DFS (PSOGI: HR 12.7, p=0.001; AJCC: HR 3.7, p<0.001). The predictive capacity of both classification systems was unacceptable for OS and DFS (concordance-index values <0.7). Conclusions Both classification systems behaved similarly when stratifying our series into prognostic groups. The PSOGI classification provides better histopathological description, but histology alone is insufficient for adequate patient prognostication.