Cancer of unknown primary: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up.

Contemporary primary treatment of women with stage II-IV low-grade serous ovarian/peritoneal cancer (LGSOC): Determinants of relapse and disease-free survival.

Psammocarcinoma is an uncommon subtype of low-grade serous carcinoma. It is characterized by the presence of extensive psammoma bodies and can have either an ovarian or peritoneal origin. To our knowledge fewer than 30 cases of primary peritoneal psammocarcinoma (PPP) have been reported in the English literature. We report a rare case of  PPP in a 74-year-old female, discovered fortuitously within a laparotomy for gallbladder lithiasis. At laparotomy, multiple nodular implants involving the omentum, the peritoneum and a magma of intestinal loops in the right iliac fossa were noted. A biopsy from nodules was performed. Gross examination showed multiple nodules of different sizes in the fat tissue. Pathologic examination showed massive psammoma bodies representing more than 75% of the tumor. The final diagnosis was psammocarcinoma. Our patient was referred to the gynecologic department for further investigation and to ascertain whether the tumor arose from the ovaries or peritoneum. Hysterectomy, bilateral adnexectomy and omentectomy were performed. Macroscopic examination showed that both ovaries were intact having a normal size. No invasion of ovarian stroma was shown in microscopic examination. The patient died of SARS-CoV-2 (COVID-19) six days after the surgery. PPP is a rare type of  low-grade serous carcinoma. The behavior of this tumor is unclear, and the treatment is not standardized because of its rarity and lack of long-term follow-up. More cases need to be studied for better understanding and improvement of the management protocols.

https://f1000research.com/articles/11-696/v1/pdf

Case Report: Fortuitous discovery of primary peritoneal psammocarcinoma

Purpose Psammocarcinoma (PK) is a rare disease of unknown origin. We aimed to report the characteristics, management and survival of patients operated on for PK within the French Network for Rare Peritoneal Malignancies (RENAPE) expert centers. Patients and methods All consecutive cases of PK operated within all 26 RENAPE centers between 1997 and 2018 were retrospectively analyzed. Results Twenty-five patients were identified. The median age was 53 years [range 17–78]. None of the patients had extra peritoneal metastases at diagnosis. A median of 6 cycles of carboplatin-based systemic chemotherapy was delivered in 52% preoperatively (n = 13) and 56% postoperatively (n = 14); associated with placlitaxel for 12 patients. All patients were operated on. The median PCI was 23 [0–33]. Eighty-four percent had a complete cytoreductive surgery through digestive (n = 7), spleen (n = 3), pancreas (n = 1) resections and/or multiple peritonectomies (n = 11). Five patients (20%) had intraperitoneal chemotherapy. Morbidity (Dindo-Clavien ≥3) was 12%. No postoperative death occurred. After a median follow-up of 42 months (range [2–194]), the median overall (OS) and progression-free (DFS) survival times were respectively 128 months and 31 months. Eighteen patients recurred (72%), mainly in the peritoneum (n = 16). Four of them (22%) were reoperated. The 5 and 10-year DFS rates were both 20.3%. The 5 and 10-year OS rates were 62% and 51.7%, respectively. A complete cytoreductive surgery was associated with a better OS and DFS in a univariate analysis. Conclusion Complete cytoreductive surgery is the cornerstone of the PK's management as a primary treatment. Recurrence remains common and new adjuvant strategies seem needed.

Anne Chevallier

Papers

Ovarian and peritoneal psammocarcinoma: Results of a multicenter study on 25 patients.