Peritoneal mesothelioma and primary peritoneal carcinoma are often found during surgical and gynecologic procedures because of the difficulty of diagnosis. Mesothelioma was first reported in 1908 by Miller et al. The occurrence of mesothelioma was first suggested to be associated with exposure to asbestos dust by Wagner et al. in 1960. It has been suggested that the disease may be associated with radioactive materials, viruses, genetic susceptibility and chronic inflammatory stimuli, suggesting that some mesothelioma development is not related to asbestos. Mesothelioma is a highly aggressive tumor and there is a lack of reliable serologic tumor indicators. Robinson et al. in Australia reported that serum soluble mesothelial-related protein (SMR) was useful in predicting and diagnosing mesothelioma (Lancet 2003;362:1612). 37 of 44 patients (84%) with histologically confirmed mesothelioma had elevated SMR levels, whereas only 3 of 160 patients (2%) with other tumors, other inflammatory lung disease, and pleural disease had SMR was elevated in 1 of 28 healthy controls without a history of asbestos exposure and in 7 of 40 controls with a history of asbestos exposure, of whom 3 and 1 developed mesothelioma and lung cancer, respectively, during the 1- to 5-year follow-up period. Clinical features: The incidence rate is 1~2/million in the general population, the onset is insidious, and most of them are asymptomatic in the early stage. If heterogeneous mesothelial cells with malignant features are found in the ascites, it can help to make the diagnosis, but the positive rate is extremely low, and the diagnosis needs to be confirmed by pathological histological examination. Mesothelioma Mesothelioma is one of the pelvic peritoneal tumors that occurs from the mesothelial cells of the uterine plasma membrane. Mesothelial cells are primitive and pluripotent and can form a variety of different tissue types during their proliferation and development. Therefore, a variety of names appear in the literature, such as adenofibroma, adenoma, hemangioma-like tumor and lymphangioleiomyoma. Uterine mesothelioma is rare and occurs mostly in middle-aged or older women. There are no specific clinical symptoms. Its presentation is identical to that of uterine fibroids and is easily confused with uterine sarcoma. The tumor is usually found in the subplasmic layer of the uterine horn and is diffusely scattered or forms cords or sheets. They are usually small in size (<3 cm in diameter), hard, without envelope, and grayish white or grayish yellow in cut surface. Microscopically, the tumor cells are rectangular, spindle-shaped, round or polygonal in shape. There are basically three types of cell morphology, namely epithelioid cells, fibroblastic spindle cells and pleomorphic sarcoma-like cells. According to the pathological histological morphology, they can be classified as plasmacytoid papillary, solitary fibrous and adenomatous. Diagnosis: The presentation is identical to that of uterine leiomyoma and is easily confused with uterine sarcoma. Primary mesothelioma of other organs should be excluded before the diagnosis of primary uterine mesothelioma. Treatment: It is generally advocated that total hysterectomy should be performed for those located between the uterine wall, small in size and without special cellular anomalies on microscopic examination; if the tumor is large and protrudes significantly into the abdominal cavity or uterine cavity, especially those of plasma papillary type, extensive complete resection with appropriate adjuvant radiotherapy or chemotherapy should be performed according to the principles of uterine malignancy management. Extrinsic peritoneal plasmacytoid papillary carcinoma Since Suerdlou first reported a case of pelvic peritoneal mesothelioma like papillary cystic adenocarcinoma of the ovary in 1959, many scholars have reported many similar cases, such as mesothelioma, primary peritoneal papillary plasmacytoid cystic adenocarcinoma, multifocal extrinsic plasmacytoid carcinoma of the ovary, extrinsic peritoneal plasmacytoid papillary carcinoma of the ovary (EPSPC), etc. BLCss reported more than 250 cases. More than 250 cases. Rarely reported in China. Extraovarian peritoneal serous papillary carcinoma (EPSPC) is a malignant tumor that originates from the peritoneal mesothelium and sometimes involves the surface of the ovary in a multifocal manner. EPSPC is a multifocal malignant tumor originating from the peritoneal mesothelium and sometimes involving the ovarian surface. It is asymptomatic in the early stage, but in the late stage, it may have gastrointestinal symptoms such as abdominal distension, ascites and poor appetite, and the primary lesion is often not found in the gastrointestinal system. There are two types of tissue sources for EPSPC: one is the malignant transformation of ovarian tissues remaining during the gonadal migration in embryonic period, and the other is the mesothelium of peritoneal epithelium and ovarian epithelium with potential Mullerian system, which becomes cancerous when stimulated by certain carcinogenic factors. The exact etiology of EPSPC is unknown, but Komatsu et al. suggested that the risk factors for EPSPC are similar to those for epithelial ovarian cancer, such as infertility and high gonadotropin levels. Most of the diagnostic criteria for EPSPC developed by the American Gynecologic Oncology Group (GOG) are now adopted in China (pathologic features of EPSPC): tumors mostly grow in the pelvis and abdominal peritoneum, forming multiple or multiple tumor nodules. The ovaries were basically normal in size bilaterally. The histological structure is consistent with ovarian plasmacytic cystic adenocarcinoma, and the tumor cells are mostly dwarf columnar, arranged in papillae, with common sand granule formation and poorly differentiated. The clinical presentation was nonspecific. Since EPSPC is similar to epithelial ovarian carcinoma and both CA125 are significantly increased, it can be used as one of the diagnostic criteria for this tumor. The treatment of EPSPC is currently based on surgery and chemotherapy, and because EPSPC and papillary plasmacytoid ovarian cancer (PSOC) have the same origin and similar histological features, the PAC regimen applicable to PSOC is often used to treat EPSPC. with an interval of 21 days for 6 courses of treatment. The prognosis of EPSPC is generally considered to be poor. I. Case 1: 43-year-old, married. She was admitted to the hospital on December 4, 1998, due to heavy menstrual flow with abdominal distension and "uterine fibroids and mixed pelvic tumor". Gynecological examination: the uterus was enlarged like 7 weeks of pregnancy, hard and hypermobile. Ultrasound showed: hypoechoic 5.5 cm×4.8 cm in the anterior wall of the uterus, irregular dark area 8.9 cm×5.9 cm in the posterior right side of the uterus with a little separation and irregular light mass 6.9 cm×5 cm, suggesting: uterine fibroids and mixed pelvic mass. On December 23, a dissection was performed. Intraoperatively, 300 ml of yellowish ascites was seen, the uterus was enlarged as at 8 weeks' gestation, there was a 7 cm × 5 cm × 5 cm bulge at the right side of the uterine fundus, and a 8 cm × 6.5 cm × 5 cm substantial mass in the tau fossa of the posterior uterine wall with papillary, brittle tissue, no peritoneum, and adhesions to the cervix and sigmoid colon. There was a 1.5 cm × 1 cm tumor foci in the left round ligament with normal bilateral ovarian morphology. Frozen section of the tumor foci in the round ligament and the tau fossa was taken immediately and reported: adenocarcinoma. Total hysterectomy with both adnexa and large omentum and appendix was performed. Intraoperative intraperitoneal cisplatin 60 mg was left in place. Pathology: (uterine rectal recess) primary peritoneal papillary adenocarcinoma (endometrioid adenocarcinoma predominantly) grade I, periprosthetic plasma membrane in the lower posterior uterine wall, minimal mesothelium showing early carcinoma, reactive mesothelial hyperplasia of the greater omentum, minimal adenocarcinoma foci seen, intermyometrial smooth muscle tumor, endometrial polyps, no carcinoma foci seen in the bilateral ovaries, chronic inflammation of the bilateral fallopian tubes. Postoperative CP regimen: cyclophosphamide 750 mg/m2 intravenous chemotherapy and cisplatin 75 mg/m2 intraperitoneal chemotherapy for 6 courses. On July 9, 1999, a two-visit plus pelvic lymph node dissection was performed, with no tumor foci visible to the naked eye and negative lymph nodes on pathological examination. He was followed by the above chemotherapy for 2 times after the operation, and is currently under follow-up. Case 2: 41-year-old married man who visited the hospital for poor bowel movement and increased frequency. She was hospitalized on June 7, 1999. Gynecological examination: 7 cm×6 cm round substantial mass between posterior vaginal wall and rectum, smooth surface, no pressure pain, 1 cm×1.5 cm nodule in the anterior part of the mass near the left fornix, light cervical erosion, mid-positioned uterine body. Anal examination: 7 cm×6 cm mass in the anterior rectal wall, smooth surface, convex to the posterior wall, passable by fingers, no blood staining in the finger sleeve. A caesarean section was performed on June 16, 1999. There was a 10 cm × 8 cm × 7 cm cystic-solid interstitial mass between the uterine rectum, with an uneven surface and infiltration with the presacral and left pelvic wall. Because of the difficulty in removing the mass, mass aspiration was performed. Pathology was adenocarcinoma cells. Interventional chemotherapy with femoral artery cannulation was administered twice with cisplatin 80 mg and adriamycin 70 mg. reoperation was performed on August 8 and both ovaries were normal to the naked eye. There were two masses at the junction of the sigmoid colon and rectum, 3 cm × 2 cm and 2 cm × 2 cm, respectively, which were hard and adherent to the posterior wall of the cervix and infiltrated the left parametrium and the left pelvic wall. There was a 6 cm×5 cm×5 cm mass between the posterior vaginal wall and the anterior rectal wall, with a smooth, hard surface and poor mobility. A total hysterectomy with Hartman's surgery was performed. The pathology was an extra-ovarian plasmacytic papillary cystic adenocarcinoma (granuloma) (utero-rectal fossa) with a mass of 8 cm × 5 cm × 5 cm, tumor infiltrating the plasma membrane layer of the sigmoid colon and 5/11 lymph nodes adjacent to the intestinal wall (cancer metastasis was seen, and the left ovarian plasmacytic papilloma was confined to the ovarian epithelium). One postoperative intraperitoneal chemotherapy with mitomycin 8 mg, 5 fluorouracil 1 g, and cisplatin 80 mg. is currently under follow-up. Case 3: The patient was 61 years old and married. He was admitted to the hospital for more than 2 months with a feeling of anal swelling, with a feeling of urgency and heaviness, without pus and blood in the stool, and without obvious abdominal pain. Physical examination: no enlargement of superficial lymph nodes, flat and soft abdomen, no palpable mass, no pressure pain and rebound pain, active bowel sounds, mobile turbid sounds (-). Ultrasound: uterus 4.9cm×4.9cm×2.2cm, 6.5cm×2.3cm strong echogenic light mass outside the posterior uterus. CT examination: anterior rectal wall tumor. After admission, a dissection was performed and the uterus was seen to be less than normal and smooth, the right adnexa (-), and a 9-10 cm diameter mass on the left side of the rectal fossa, which was not smooth and brittle, with adhesions to the left adnexa, rectum and pelvic wall. The pelvic peritoneum and rectum each had a 2 cm large nodule, and no nodule was palpable around the greater omentum and liver and spleen. Intraoperative rapid pathology: plasmacytic papillary cystic adenocarcinoma of the ovary. Intraoperatively, the gynecologist was asked to perform a large lesion excision and found that the left adnexa was normal. The uterus and bilateral adnexa were removed and the pelvic funnel ligament was ligated at a high level. Postoperative pathology (confirmed by immunohistochemical examination): malignant mesothelioma of the peritoneum. Chemotherapy with carboplatin, cyclophosphamide, adriamycin, and 5-fluorouracil was administered. Forty months after surgery, the patient developed large omental and hepatic metastases and died. IV. Case 4: The patient was 65 years old, married, and was seen at an outside hospital for paroxysmal abdominal pain, bloating, and diarrhea for more than 1 month and aggravated for more than 10 days. Physical examination: frog-shaped abdomen, abdominal tenderness, left lower abdominal tenderness, and mobile turbid sounds (+). Gynecological examination: the uterus was indistinct on palpation, and a solid mass was palpated in the rectal fossa of the uterus, about 4 cm × 3 cm × 3 cm, soft in texture. CT examination of the pelvis: malignant tumor in the pelvis with extensive peritoneal implantation; large amount of ascites. After admission, an exploratory dissection was performed and 5000ml of ascites was seen. There were cancer foci of different sizes in the peritoneum, greater omentum, mesentery, hepatic hilum and around the uterus and adnexa of the pelvic cavity; the uterus and ovaries were atrophic, and the cancer tissues on the greater omentum adhered to form a mass, about 15cm×10cm×6cm in size, and the liver surface was smooth. The large omental mass and part of the lesion were excised, and an abdominal chemotherapy pump was placed. Pathology report: tubular adenocarcinoma with metastasis (large omentum). After surgery, 6 courses of combined intraperitoneal and intravenous chemotherapy (carboplatin, adriamycin, cyclophosphamide, vincristine) were administered, followed by a second dissection: no abnormalities were seen in the uterus and adnexa, and scattered yellow nodules were seen on the peritoneal surface and round ligament, and hysterectomy and adnexal resection were performed. Pathology report: no cancer cells were found. After that, she came to our hospital for 4 courses of chemotherapy (combined abdominal and intravenous chemotherapy). At present, the patient has no discomfort, and no significant abnormality was found in pelvic examination, ultrasound and CT examination. The pathological section was reviewed and the diagnosis was peritoneal malignant mesothelioma. The patient has survived for 38 months so far. V. Case 5: The patient was 50 years old and married. She presented to the clinic with abdominal distension for more than 20 days, aggravated for 5 days, with lower abdominal cramping during stool, low urine output, inability to lie down, and minimal diet, and was proposed to be diagnosed with ovarian cancer. Physical examination: abdominal distension, frog-shaped abdomen, full-term pregnancy size, abdominal wall tension, light pressure pain, mobile turbid sounds (+). Gynecologic examination: uterus and adnexa were indistinct on palpation. There was a pelvic mass with unclear boundaries and inactivity. Ultrasound: uterus 5.5cm×4.1cm×3cm, normal shape, homogeneous echogenicity, 4.1×4.5cm×4.1cm mixed echogenicity and 3.3cm×3.3cm echolucency detected outside the left front of the uterus, large amount of ascites detected in the abdominal cavity, suggesting pelvic mass (ovarian cancer?). The pelvic mass (ovarian cancer?) was detected. After admission, diuresis was given, ascites was released by laparotomy (cancer cells were found in ascites), and carboplatin intraperitoneal chemotherapy was administered once, and then a dissection was performed. During the operation, about 7000ml of light tea-colored ascites was released. Intraoperatively, it was seen that the peritoneum was thickened, the greater omentum was "pie-like", there was a solid mass of 6cm×5cm×4cm in the fundus of the uterus, the uterus and the right adnexa were eroded, encircled and lumped by cancerous tissue, the left adnexa (-), the liver and stomach were generally normal, the lower pole of the spleen was slightly eroded, the surface of the intestine There were scattered cancer foci in the mesentery of the intestine, with varying sizes. Bilateral adnexal, appendiceal and greater omental resections and local lesion removal were performed, and an abdominal chemotherapy tube was placed. Intraoperative and postoperative PC regimen chemotherapy (combined abdominal and intravenous chemotherapy) was administered. Intraoperative rapid pathology: uterine leiomyoma with a few cancerous tissues detected on the surface, (right adnexal) carcinoma probably hypofractionated squamous cell carcinoma. Postoperative pathology (confirmed by immunohistochemistry): malignant mesothelioma of the peritoneum. Currently, the patient continues to complete all courses of chemotherapy and has survived with the tumor for 9 months.