Platinum-based chemotherapy is the standard chemotherapy for high grade serous ovarian cancer and primary peritoneal high-grade serous carcinoma. PARP inhibitors have changed the paradigm of the treatment in platinum-sensitive ovarian cancers and primary peritoneal high-grade serous carcinoma with BRCA1/2 mutation or homologous recombination deficiency (HRD). Platinum-resistant ovarian and primary peritoneal high-grade serous carcinoma have a lower chance to treat and have worse outcomes. We described a case of patient with a platinum resistant primary peritoneal high-grade serous carcinoma with a rare somatic BRCA2 amplification. There are no guidelines for the treatment of ovarian cancer or primary peritoneal high-grade serous carcinoma with BRCA2 amplification. BRCA2 amplification could result in extreme homologous recombination repair (HRR) pathway efficiency and in less platinum sensitivity, which could be a molecular signature for platinum resistance. Free platinum chemotherapy regimens could be more effective in cases with BRCA2 amplification. Further studies are necessary to establish better approaches and strategies for oncological management and treatment in BRCA2 amplification high grade ovarian cancer and primary peritoneal high-grade serous carcinoma.

Primary serous peritoneal carcinoma (PPC) is a rare malignancy often presenting with a significant disease burden and a poor prognosis. A 65-year-old female was seen in the surgical outpatient clinic with a two-month history of weight loss, altered bowel habits and a CT scan characterizing a heterogenous right paracolic gutter mass and suspicious liver lesions. At colonoscopy, a prominent appendiceal orifice was biopsied to be poorly differentiated carcinoma favouring gynaecological tract origin. The patient was admitted with an acute small bowel obstruction secondary to progression of metastases and underwent neoadjuvant chemotherapy with a near complete response on repeat staging. A debulking hysterectomy, bilateral salpingo-oophorectomy, pelvic peritonectomy and small bowel nodule excision were performed. The diagnosis of PPC was confirmed when no malignancy was found in the pelvic organs. The presence of intraluminal colonic metastasis with PPC is exceedingly rare with this being only the third such case in the literature.

With the advancement in technologies and the development of a vast variety of tests, diagnosing diseases has become relatively easy. However, certain diseases are challenging to diagnose due to their similarities with other disease processes. Primary peritoneal carcinoma (PPC) is one of the infrequent tumors that has a resemblance to an ovarian tumor, often making it hard to diagnose. The symptoms are non-specific, and by the time primary peritoneal cancer is diagnosed, the patient is usually at an advanced stage. Although diagnosis might be suspected based on presenting symptoms, it is rarely confirmed with symptomatology alone, requiring additional tumor markers or radiological studies. Sometimes it is diagnosed after surgical removal of the lesion. Several similarities have been described between PPC and ovarian cancer, with some studies explaining the differences as well. We highlight the importance of careful interpretation of imaging studies for the timely diagnosis of PPC. However, several factors can interfere with the analysis of test results leading to delays in diagnosis and management. Interpretation of imaging becomes difficult, especially in patients with significant ascites.

The current theory of carcinogenesis for the deadliest of \'ovarian\' cancers-high-grade serous carcinoma (HGSC)-holds that the malignancy develops first in the fallopian tube and spreads to the ovaries, peritoneum, and/or regional lymph nodes. This is based primarily on the observation of early forms of serous neoplasia (serous tubal intraepithelial lesions [STILs], and serous tubal intraepithelial carcinomas [STICS]) in the fimbria of women undergoing risk reduction surgery. However, these lesions are uncommon in the general population, confer a low risk (5%) of HGSC following their removal in at-risk women with germ-line BRCA1/2 mutations, and require 4 or more years to recur as intraperitoneal HGSC. These features suggest that isolated STILs and STICs behave as precursors, with uncertain cancer risk rather than carcinomas. Their evolution to HGSC within, or after, escape from the tube could proceed stepwise with multiple biologic events; however, it is unclear whether tubal or ovarian HGSCs encountered in the setting of advanced disease evolved in the same fashion. The latter scenario could also be explained by a \'catastrophic\' model in which STICs suddenly develop with invasive and metastatic potential, overwhelming or obscuring the site of origin. Moreover, a similar model might explain the sudden emergence of HGSC in the peritoneal cavity following escape of precursor cells years before. Long-term follow-up data from opportunistic or prophylactic salpingectomy should shed light on where malignant transformation occurs, as well as the timeline from precursor to metastatic HGSC. © 2022 The Pathological Society of Great Britain and Ireland.

BACKGROUND: Primary peritoneal carcinoma (PPC) at presentation often masquerades as epithelial ovarian carcinoma (OC) but behaves different with respect to treatment response, recurrence patterns and has inferior outcomes. The objective of this study is to compare the clinicopathological features and survival outcomes of PPC and OC.
METHODS: Prospectively maintained database of patients presenting to the gynecologic oncology department at a tertiary hospital was reviewed between 1st January 2010 and 31st December 2020. A comparative analysis of high-grade serous stage III/IV PPC and OC was done. Demographics, treatment details, complications and survival outcomes were collected from electronic medical records.
RESULTS: 151 OC and 69 PPC patients were included. A higher proportion of women with PPC had reduced performance status prior to hysterectomy with salpingo-oophorectomy, a shorter symptom to treatment interval, and large volume ascites. A significantly lower number of women with PPC (4.3 vs. 46.1%; P < 0.001) underwent primary cytoreduction, had a lower median surgical complexity score (3 vs. 4; P < 0.001) but higher recurrence rates (66.7 vs. 47.0%; P = 0.041) as compared to the patients with OC. The median progression-free survival (PFS) was 18 (15-20) months in PPC and 23 (17-28) months in OC patients (log-rank P = 0.034), while the median overall survival (OS) was similar (44 vs. 48 months; log-rank P = 0.696). The presence of extraperitoneal disease and interval cytoreduction was associated with shorter PFS. Suboptimal cytoreduction and delay in adjuvant chemotherapy beyond 6 weeks post-surgery was associated with reduced OS.
CONCLUSIONS: PPC is an aggressive disease with lower PFS compared to OC. Commonly presenting with large volume carcinomatosis, it is not amenable for primary cytoreduction, making the usage of neoadjuvant chemotherapy a common practice and pragmatic approach.

Peritoneal tumors are very uncommon and among them, primary peritoneal clear cell carcinoma is extremely rare and often misdiagnosed as others subtypes. There are only 13 cases of primary peritoneal clear cell carcinoma previously reported in the literature and there are no reports about cutaneous metastasis in this setting and only brain metastases were described to be associated with other primary peritoneal carcinoma subtypes. More information about this topic is needed and so we are presenting a new case of primary peritoneal clear cell carcinoma with cutaneous and cerebral metastases in a 34-year-old female.

OBJECTIVE: The aim of this study was to investigate whether serum HE4 was associated with clinical risk prognostic factors and survival outcome.
METHODS: In this study, 72 patients with primary peritoneal carcinoma (PPC) from January 2011 to October 2019 participated. Serum HE4 and CA125 levels were detected at primary diagnosis, post-surgery, pre-recurrence and the presence of recurrence. The relations between serum HE4 levels with clinical prognostic factors were analyzed, and the hazard ratios between serum HE4 levels with overall survival and recurrence-free survival were also analyzed by univariate and multivariate survival analysis.
RESULTS: HE4 and CA125 levels were significantly elevated in serous type, high histological grade, advanced stage and positive lymph node status and residual tumor diameter more than 1 cm, respectively, compared with those in non-serous type, low histological grade, early stage, negative lymph node status and residual tumor diameter no more than 1 cm, respectively. HE4 was an independent prognostic factor for recurrence-free survival and overall survival with hazard ratios of 5.36 (95% confidence interval: 2.19-13.15) and 4.48 (95% confidence interval: 1.87-10.74), respectively.
CONCLUSIONS: HE4 is correlated with clinical risk prognostic factors in PPC and is effective in the recurrence detection and predicting outcome in PPC patients.

OBJECTIVE: Serous tubal intraepithelial carcinoma (STIC) is currently considered the precursor lesion of pelvic high-grade serous carcinoma. The management of STIC diagnosed after risk-reducing salpingo-oophorectomy (RRSO) in women with BRCA1-2 variants remains unclear. The aim of our study was to evaluate the incidence of STIC, serous tubal intraepithelial lesions (STIL) and occult invasive cancer (OC) and to determine the long-term outcomes of these patients.
METHODS: We conducted a retrospective study of patients with BRCA 1-2 variants who underwent RRSO between January-2010 and Dicember-2020 at the Clinic of Gynaecology of University of Padova.
METHODS: women with a negative pelvic examination at the last screening prior to RRSO, patients with fallopian tubes analysed using the SEE-FIM protocol.
METHODS: patients with a positive gynaecologic screening or with ovarian/tubal cancer prior to RRSO.
RESULTS: We included 153 patients. STICs were diagnosed in 4 patients (2.6%) and STILs in 6 patients (3.9%). None of the patients with STIC underwent restaging surgery or adjuvant chemotherapy; all patients were followed closely every 6 months. None of the patients developed primary peritoneal carcinomas (PPCs) with a median FUP of 54.5 months (15-106). OC was diagnosed in 3 patients (2%). All patients with OC underwent staging surgery, and one patient developed a peritoneal carcinoma (PC) after 18 months by staging surgery.
CONCLUSIONS: The incidence of STIC, STIL and OC after RRSO in BRCA1-2 variants was low. Our results demonstrated that long-term close surveillance in patients diagnosed with STIC should be considered a possible management strategy.

A 45-year-old multiparous woman with a STK11 mutation and a history of Peutz-Jeghers syndrome underwent radical hysterectomy and bilateral salpingo-oophorectomy for a gastric-type cervical mucinous carcinoma. Four and a half years later, blood tests revealed elevations in CEA and CA125 tumor marker levels, and computed tomography showed multiple calcifications in the peritoneum. Peritoneal dissemination was suspected, and a laparoscopic biopsy was performed. Histopathology showed a high-grade serous carcinoma, and the patient was diagnosed with a metachronous stage IIIC primary peritoneal carcinoma. She had no BRCA1/2 mutation. After chemotherapy with docetaxel, carboplatin, and bevacizumab, she achieved complete remission.

The findings of the DESKTOP 3 (Du Bois et al., 2017) ​study advocate secondary cytoreduction in patients with disease relapse of ovarian or peritoneal malignancy meeting specified criteria. We present a surgical video demonstrating the technique of laparoscopic resection of single site pelvic side wall recurrence 6 years after stage IIIc high grade serous primary peritoneal cancer. In 2014, our patient underwent 3 cycles of neo-adjuvant Cisplatin/Paclitaxel, followed by interval debulking surgery - achieving R0 - for stage IIIc high grade serous primary peritoneal carcinoma. Six years later, at aged 81 years, routine surveillance identified a rising CA 125 level of 91. CT imaging confirmed single site recurrence, reporting an isolated enlarged (3.5 × 2 cm) external iliac lymph node. Given the prolonged disease-free interval, absence of ascites, resectability of recurrent disease and fitness for surgery - secondary cytoreduction was undertaken. Our surgical video demonstrates gaining laparoscopic retroperitoneal access and the subsequent development of the lateral pelvic spaces to facilitate safe excision of disease relapse with a clear surgical margin, Our surgical video demonstrates the feasibility of minimal access surgery for single site recurrence of peritoneal carcinoma, highlighting the importance of understanding and exposing pelvic sidewall anatomy to enable safe and adequate resection - systematically identifying and preserving the ureter, iliac vessels and obturator nerve.