A case of Pseudomyxoma Peritonei of an unexpected origin

Background Pseudomyxoma peritonei (PMP) is a complex and partially understood disease defined by mucin deposits in the peritoneal cavity, mostly of appendiceal origin caused by the rupture of a mucocele often containing Low or High grade Appendiceal Mucinous Neoplasm (LAMN/HAMN). Other origins include primitive ovarian mucinous cystadenoma or cystadenocarcinoma almost always with an associated teratoma, but to our knowledge no case of ovarian teratomatous appendiceal-like mucocele with LAMN has been reported as a cause of PMP. Case presentation A 25-year old female with infertility was diagnosed with an isolated left ovarian tumor in a context of PMP. Histological examination revealed an ovarian teratoma containing an appendiceal-like structure with mucocele and LAMN, without any associated lesion of the appendix on full histological analysis. Molecular characterization of the ovarian lesion showed co-KRAS and GNAS mutations, as described in PMP of appendiceal origin, while only KRAS mutations are reported in primitive ovarian mucinous tumor. Conclusions Detection of co-KRAS and GNAS mutations in our case of ovarian teratomatous appendiceal-like mucocele with LAMN shows that when PMP derives from a mucinous ovarian lesion (with histological proof of none-appendiceal involvement), it is probably of a digestive teratomatous origin, emphasizing the need to actively search for tetatomatous signs in a context of ovarian PMP.

A case of pancreaticoduodenectomy and partial hepatic resection as repeat cytoreductive surgery for recurrent pseudomyxoma peritonei

Background For recurrent pseudomyxoma peritonei (PMP), repeat cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) can provide survival benefits if patients are carefully selected. We describe a case of pancreaticoduodenectomy and partial liver resection (HPD) as the repeat CRS for a recurrent tumor that infiltrated the pancreatic head around the hepatic hilum. This is the first report of HPD for recurrent PMP. Case presentation The patient was a 58-year-old male without comorbidities. In 2001, he was diagnosed with PMP at the time of laparoscopic cholecystectomy. In 2004, CRS, including total peritoneal resection, pyloric gastrectomy, splenectomy, and right hemicolectomy with HIPEC was performed (peritoneal cancer index (PCI) = 28). In 2008, the first repeat CRS with HIPEC was performed (PCI = 14). In 2016, fourth repeat CRS, including partial hepatectomy with HIPEC for recurrence of the round ligament of the liver, was performed. In 2017, a tumor of 5 cm in size was observed from the hepatic hilum to the pancreatic head, which infiltrated the main pancreatic duct. Other tumors 2 cm in size were observed (PCI = 7). We performed the fifth repeat CRS, including HPD. The adhesions of the small intestine from around the liver to the lower abdomen were detached for the reconstruction of pancreatojejunostomy and cholangiojejunostomy. The uncinate approach was applied for the pancreatic head resection because it was difficult to identify the cranial part of the pancreas due to adhesions in the hepatoduodenal ligament and the omental bursa. We approached to the origin of the extrahepatic Glissonean pedicle by resecting a part of the liver around the hepatic hilum using transhepatic hilar approach. A complete cytoreduction was achieved. The postoperative pathological diagnosis was a recurrence of PMP, which is equivalent to peritoneal mucinous carcinomatosis. He was discharged on the 22nd postoperative day without major postoperative complications. The patient survived without recurrence four years after HPD. Conclusions Even for recurrence around the hepatic hilum and the pancreatic head, repeat CRS can be safely performed by applying the techniques of hepatobiliary pancreatic surgery.

Tumor-stroma ratio as a new prognosticator for pseudomyxoma peritonei: a comprehensive clinicopathological and immunohistochemical study

Background As a rare clinical tumor syndrome with an indolent clinical course and lack of pathognomonic symptoms, pseudomyxoma peritonei (PMP) is usually diagnosed at an advanced stage. In-depth pathological analysis is essential to assess tumor biological behaviors, assist treatment decision, and predict the clinical prognosis of PMP. The tumor-stroma ratio (TSR) is a promising prognostic parameter based on the tumor and stroma. This study explored the relationship between TSR and the pathological characteristics and prognosis of PMP. Methods PMP patients with complete data who underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy were enrolled. The TSR of postoperative pathological images was quantitatively analyzed by Image-Pro Plus. Then the relationship between TSR and the clinicopathological characteristics, immunohistochemical characteristics and prognosis of PMP was analyzed. Results Among the 50 PMP patients included, there were 27 males (54.0%) and 23 females (46.0%), with a median age of 55 (range: 31–76) years. 25 (50.0%) patients were diagnosed with low-grade PMP (LG-PMP), and 25 (50.0%) were diagnosed with high-grade PMP (HG-PMP). There were 4 (8.0%) patients with vascular tumor emboli, 3 (6.0%) patients with nerve invasion, and 5 (10.0%) patients with lymph node metastasis. The immunohistochemical results showed that the Ki67 label index was < 25% in 18 cases (36.0%), 25 - 50% in 18 cases (36.0%) and > 50% in 14 cases (28.0%). The range of TSR was 2 - 24% (median: 8%). The cutoff value of TSR was 10% based on the receiver operating characteristic (ROC) curve and X-Tile analysis. There were 31 (62.0%) cases with TSR < 10% and 19 (38.0%) cases with TSR ≥ 10%. The TSR was closely related to histopathological type (P < 0.001) and Ki67 label index (P < 0.001). Univariate analysis showed that preoperative carcinoembryonic antigen (CEA), preoperative carbohydrate antigen 19–9, pathological type, vascular tumor emboli and TSR influenced the prognosis of PMP patients (P < 0.05). Multivariate analysis showed that preoperative CEA, vascular tumor emboli and the TSR were independent prognostic factors. Conclusions The TSR could be a new independent prognosticator for PMP.

Novel Perspectives in Pseudomyxoma Peritonei Treatment

Pseudomyxoma Peritonei (PMP) is an anatomo-clinical condition characterized by the implantation of neoplastic cells on peritoneal surfaces with the production of a large amount of mucin. The rarity of the disease precludes the evaluation of treatment strategies within randomized controlled trials. Cytoreductive Surgery (CRS) combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) has proven to be the only therapeutic option with potential chances of cure and long-term disease control. The present review discusses the epidemiology, pathogenesis, clinical presentation and treatment of PMP, focusing on the molecular factors involved in tumor progression and mucin production that could be used, in the upcoming future, to improve patient selection for surgery and to expand the therapeutic armamentarium.

Appendiceal Mucocele - A Review of Literature with a Case Report

Background: Appendiceal mucoceles represent neoplastic and non-neoplastic, dilatated, mucus filled appendix vermiformix. Appendectomy is obligatory due to a possible malignancy. It is crucially important to avoid rupturing of the mucocele because it can result in pseudomyxoma peritonei, with high morbidity and mortality. Case Report: We presented a 52-year-old man with pain and palpable mass in the lower right quadrant of the abdomen. The mucocele was removed without a rupture, and the patient was discharged from the surgical department one day after the surgery without a complication. Discussion: The resection must be done very carefully, because the rupture of a mucocele can cause pseudomyxoma peritonei, a very dangerous and often lethal condition. Due to the concern of rupture, we performed the classical resection through laparotomy. Conclusion: It is very important, especially for young, inexperienced surgeons to be aware of this rare diagnosis and perform a surgical intervention according to the guidelines of good clinical practice.