Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases.

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

Validation of European evidence-based guidelines and American College of Gastroenterology guidelines as predictors of advanced neoplasia in patients with suspected mucinous pancreatic cystic neoplasms.

BACKGROUND AND AIM: The European evidence-based guidelines (EEG) and American College of Gastroenterology Guidelines (ACGG) have been published to guide the management of pancreatic cystic lesions. We aim to evaluate the value of both guidelines in predicting advanced pancreatic cystic lesions (A-PCLs) with preoperatively imaging-suspected cystic mucinous pancreatic neoplasms (cMNs). METHODS: One hundred ninety-eight patients who underwent resections from 2013 to 2019 for suspected cMNs were retrospectively reviewed. Receiver operating characteristic curves were calculated and compared with measure diagnostic value. RESULTS: Sixty-two patients were diagnosed with A-PCLs pathologically. Cross-imaging modalities had comparable diagnostic accuracy to endoscopic ultrasound in type classification and A-PCLs prediction. Receiver operating characteristic curve comparison analyses showed that EEG absolute + MCN (EEGAM ) and EEG relative + MCN (EEGRM ) having at least one indications criteria were comparable to the ACGG (P = 0.21 and P = 0.45). For the criteria having at least two indications, ACGG was superior to EEGAM (P = 0.001) but comparable to EEGRM (P = 0.12). EEGAM ≥ 1 indication criteria was superior to ≥ 2 indications criteria (P = 0.02). EEGRM ≥ 1 indication criteria had comparable diagnostic performance with ≥ 2 indications criteria (P = 0.86). ACGG ≥ 2 indications criteria was superior to ≥ 1 indication criteria (P = 0.02). CONCLUSION: On the basis of cross-imaging evaluations, both sets of guidelines were found to be helpful in identifying A-PCLs in suspected cMNs with comparable performance. EEGAM  ≥ 1 indication criteria was superior to ≥ 2 indications criteria. ACGG ≥ 2 indications criteria was superior to ≥ 1 indication criteria.

Mucinous cystadenocarcinoma in the renal pelvis: primary or secondary? Case report and literature review.

INTRODUCTION: Cystic lesions in the renal pelvis may cause a diagnostic dilemma. These lesions may be benign or (pre)malignant and primary of secondary. CASE REPORT: A 65-year-old woman presents with a complex cystic mass in the lower pole of the left kidney measuring approximately 16 cm in size and classified as Bosniak type 2F with minimally thickened septa and thick calcifications on non-contrast-enhanced computed tomography. The histopathological findings are consistent with a mucinous cystadenocarcinoma in the renal pelvis. Given the absence of a primary focus and based on clinical and radiological examination, the diagnosis of a primary renal neoplasm is preferred. DISCUSSION: A review of the literature is performed to evaluate the histological differential diagnosis and confirm the diagnosis. Epidemiology with an overview of available similar cases since 2009, as well as etiological factors, treatment and prognosis was reviewed. CONCLUSION: Primary renal mucinous cystadenocarcinoma is an exceedingly rare tumor. Histopathology still remains the gold standard for the diagnosis of this tumor. Because of the rarity, secondary involvement from more common sites, such as ovary and gastrointestinal tract, should be thoroughly excluded.

Multiple KRAS mutations in the non-mucinous epithelial lining in the majority of mucinous cystic neoplasms of the pancreas.

AIMS: Mucinous cystic neoplasms (MCNs) of the pancreas are cystic neoplasms lined by mucinous lining epithelium (MLE) with associated ovarian-type stroma. Although a non-MLE (NMLE) can be observed in some MCNs, whether cystic neoplasms with ovarian-type stroma and NMLE should be classified as MCNs or separately designated is debated. METHODS AND RESULTS: To test this, NMLEs were defined as flat or cuboidal epithelial cells without intracytoplasmic mucin. A total of 112 MCNs were reviewed, and the epithelium was classified as NMLE or MLE. A total of 110 females and two males with a mean age of 46.5 ± 12.3 years were included in this study. At least focal NMLE was noted in 76.8% (86/112) of MCNs. The mean percentage of the neoplastic epithelium that was NMLE in these 86 cases was 46%. NMLE was predominant (>50%) in 38.4% (43/112) of cases. MCNs with NMLE were smaller (42 ± 21 mm) than those with MLE (60 ± 36 mm, P < 0.001), and all NMLEs had low-grade dysplasia. Twelve MCNs with NMLE or MLE were selected for KRAS mutation analysis with droplet digital polymerase chain reaction after laser capture microdissection. All 12 MCNs showed multiple types of KRAS mutation, which were detected in 92% (11/12) of NMLE foci and 89% (8/9) of MLE foci. Predominant NMLE was common in small MCNs with low-grade dysplasia. CONCLUSIONS: Clonal KRAS mutations were observed in both NMLE and MLE, supporting the hypothesis that MCNs with NMLE should be classified as MCNs.

Cyst location and presence of high grade dysplasia or invasive cancer in intraductal papillary mucinous neoplasms of the pancreas: a seven institution study from the central pancreas consortium.

BACKGROUND: Traditionally, intraductal papillary mucinous neoplasms (IPMNs) of the pancreas with "high risk stigmata" (HRS) or "worrisome features" (WF) are referred for resection. We aim to assess if IPMN location is predictive of harboring either high grade dysplasia (HGD) or invasive cancer (IC). METHODS: Patients undergoing resection for IPMN from seven institutions between 2000 and 2015 (n = 275) were analyzed. HRS and WF were defined by the 2012 Fukuoka international consensus guidelines. RESULTS: 168 (61%) patients had head/uncinate cysts, while 107 (39%) had neck/body/tail cysts. No differences were noted between groups with regard to age, duct type, cyst size, or presence of at least one WF. Patients with cysts in the head/uncinate were more often male (55% vs. 40%), had at least one HRS (24% vs. 11%), and more often harbored HGD or IC(49% vs. 27%)[all p < 0.05]. On multivariate analysis, only cyst location in the head/uncinate remained associated with presence of HGD or IC(odds ratio 4.76, p = 0.02). DISCUSSION: Cyst location is predictive of HGD or IC in patients with IPMNs. Head/uncinated cysts are more likely to harbor malignancy compared to those of the neck/body/tail. Additional studies are needed to confirm these findings, however, cyst location should be considered part of the decision making process for surveillance vs. resection for IPMNs.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms.

BACKGROUND: Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN. METHODS: This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded. RESULTS: The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation. CONCLUSIONS: Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.

Resection of biliary mucinous cystic neoplasms of the liver: a prospective cohort series of 13 consecutive patients.

BACKGROUND: Biliary mucinous cystic neoplasms (BMCNs) are uncommon neoplastic septated intrahepatic cysts which are often incorrectly diagnosed and have the potential for malignant transformation. OBJECTIVE: To assess the outcome of surgical resection of BMCNs. METHOD: A prospective liver surgery database was used to identify patients who underwent surgery at Groote Schuur Hospital Complex for BMCN from 1999 to 2015. Demographic variables including age and gender were documented as well as detailed preoperative imaging, location and size, operative treatment, extent of resection, histology, postoperative complications and outcome. RESULTS: Thirteen female patients (median age 45 years) had surgery. Eleven were diagnosed by imaging for symptoms. Two were jaundiced. One cyst was found during an elective cholecystectomy. Five cysts were located centrally in the liver. Before referral three cysts were treated with percutaneous drainage and two were treated with operative deroofing. Six patients had anatomical liver resections and seven patients had non anatomical liver resections of which two needed ablation of residual cyst wall. One patient needed a biliary-enteric reconstruction to treat a fistula. Median operative time was 183 minutes (range: 130-375). No invasive carcinoma was found. There was no operative mortality. One surgical site infection and one intra-abdominal collection were treated. Two patients developed recurrent BMCN after 24 months. CONCLUSION: BMCNs should be considered in middle aged women who have well encapsulated multilocular liver cysts. Treatment of large central BMCNs adjacent to vascular and biliary structures may require technically complex liver resections and are best managed in a specialised hepato-pancreatico-biliary unit.

Management of patients with pancreatic cystic lesions: A case-based survey.

BACKGROUND: Pancreatic cystic lesions (PCL), including intraductal papillary mucinous neoplasia (IPMN), harbor different malignant potential and the optimal management is often challenging. The present study aims to depict the compliance of experts with current consensus guidelines and the accuracy of treatment recommendations stratified by the medical specialty and hospital volume. METHODS: An international survey was conducted using a set of 10 selected cases of PCL that were presented to a cohort of international experts on pancreatology. All presented cases were surgically resected between 2004 and 2015 and histopathological examination was available. Accuracy of the treatment recommendations was based on the European and international consensus guideline algorithms, and the histopathological result. RESULTS: The response rate of the survey was 26% (46 of 177 contacted experts), consisting of 70% surgeons and 30% gastroenterologists/oncologists (GI/Onc). In the case of main-duct IPMN (MD-IPMN), surgeons preferred more often the surgical approach in comparison with the GI/Onc (55 versus 44%). The mean accuracy rate based on the European and international consensus guidelines, and the histopathological result, were 71/76/38% (surgeons), and 70/73/34% (GI/Onc), respectively. High-volume centers achieved insignificantly higher accuracy scores with regard to the histopathology. Small branch-duct IPMN with cysts <2 cm and malignant potential were not identified by the guideline algorithms. CONCLUSION: The survey underlines the complexity of treatment decisions for patients with PCL; less than 40% of the recommendations were in line with the final histopathology in this selected case panel. Experts and consensus guidelines may fail to predict malignant potential in small PCL.

The diagnosis of pancreatic mucinous cystic neoplasm and associated adenocarcinoma in males: An eight-institution study of 349 patients over 15 years.

BACKGROUND: Per WHO, 2000 classification, pancreatic mucinous cystic neoplasms (MCN) are defined by presence of ovarian stroma, and are primarily located in the pancreatic body/tail of females. The incidence of MCN and associated malignancy in males, since, standardization of MCN diagnostic-criteria is unknown. METHODS: MCN resections from 2000 to 2014 at eight institutions of the Central-Pancreas-Consortium were included, and divided into early (2000-2007) and late (2008-2014) time-periods. Primary aim was to characterize MCN and associated adenocarcinoma/high-grade-dysplasia (AC/HGD) in males versus females over time. RESULTS: Of 1667 resections for pancreatic cystic lesions, 349 pts (21%) had MCNs: 310 (89%) female, 39 (11%) male. Patients were equally divided between early (n = 173) and late (n = 176) time-periods. MCN in male-patients decreased over time (early: 15%, late: 7%; P = 0.036), as did pancreatic head/neck location (early: 22%, late: 11%; P = 0.01). MCN-associated AC/HGD was more frequent in males versus females (39 vs. 12%; P < 0.001). The overall rate of MCN-associated AC/HGD remained stable (early: 17%, late: 13%; P = 0.4), and was identical in males (39%) over both time-periods. Males with AC/HGD had more LN-positive disease versus females (57 vs. 22%; P = 0.039). CONCLUSIONS: As the diagnostic-criteria of MCN have standardized over time, MCN diagnosis has decreased in males and head/neck location. Despite this, MCN-associated adenocarcinoma/high-grade dysplasia has been stable and remains high in males. Any male with suspected MCN, regardless of location, should undergo resection.

Biliary tumors with pancreatic counterparts.

Some biliary diseases mimic pancreatic diseases pathologically as well as pathogenetically. Such diseases can be called "biliary diseases with pancreatic counterparts". Biliary intraepithelial neoplasm (BilIN), intraductal papillary neoplasm of bile ducts (IPNB), hepatobiliary mucinous cystic neoplasm (hMCN), and IgG4-inflammatory pseudotumor represent the biliary counterparts of pancreatic intraepithelial neoplasm (PanIN), intraductal papillary mucinous neoplasm of pancreas (IPMN), pancreatic MCN, and mass forming type 1 autoimmune pancreatitis (AIP), respectively. BilIN and PanIN represent pre-invasive intraepithelial stages of nodular sclerosing cholangiocarcinoma and pancreatic ductal adenocarcinoma, respectively. IPNB and IPMN are grossly visible, predominant papillary, intraductal neoplasms that may progress to invasive carcinoma. Morphologically similar MCNs with subepithelial ovarian-like stroma occur in both the hepatobiliary system as well as the pancreas. IgG4-inflammatory pseudotumor, usually of the lymphoplasmacytic type, and mass forming type 1 AIP represent IgG4-related disease in the biliary tree and pancreas respectively. The biliary tract, which is associated with the peribiliary glands, including the pancreatic acini, can be regarded as an incomplete pancreas, so several diseases mimicking pancreatic diseases may be expected to occur in the biliary tract (biliary diseases with pancreatic counterparts).

A giant mucinous cystadenocarcinoma of the appendix: a case report and review of the literature.

BACKGROUND: Mucinous cystadenocarcinoma is the second most common etiology of appendiceal mucocele. We report a relatively rare case of a giant appendiceal mucocele caused by mucinous cystadenocarcinoma, which occupied the entire abdomen of an adult woman. CASE PRESENTATION: A 63-year-old woman presented with a chief complaint of abdominal distention. Imaging studies showed a giant cystic mass occupying her entire abdomen. Laparotomy confirmed a giant appendiceal mucocele, and the patient underwent ileocecal resection. A mucinous deposit was not found in her abdominal cavity, and the ovaries were grossly normal bilaterally. The pathological diagnosis was mucinous adenocarcinoma with a low-grade mucinous neoplasm that invaded the subserosa. Regional lymph node metastasis was not found. She has had recurrence-free survival for 5 years. CONCLUSIONS: The present case is the largest appendiceal cystadenocarcinoma ever reported. The optimal treatment of an appendiceal neoplasm requires further research based on consensus terminology of an appendiceal mucocele.

Primary mucinous carcinoma of the vulva with signet ring cells deriving from the cloaca.

Vulvar neoplasias are rarely encountered lesions at female genital tract, regardless if they are primary or metastatic. Presence of signet ring cells in a tumour at female genito-urinary tract is highly suggestive of a metastatic lesion particularly from a gastrointestinal tumour. Here the authors present a case of vulvar carcinoma with signet ring cells with an undetermined primary site possibly originating from embryonic cloaca.

Positive expression of insulin-like growth factor-1 receptor is associated with a positive hormone receptor status in ovarian cancer.

UNLABELLED: Summary PURPOSE: Ovarian cancer is the most deadly of all gynecologic malignancies, due in part to the diagnosis at an advanced stage caused by the deficiency of specific marks and symptoms, by the absence of reliable tests for screening, and by early detection. MATERIALS AND METHODS: Insulin-like growth factor-I (IGF-I) is known to be involved in the development and promotion of diverse examples of solid tumors including ovarian cancer. IGF-I levels in local tissue are subject to both endocrine and paracrine/autocrine regulation. RESULTS: Most patients will react initially to treatment, but almost 70% of them will have a recurrence. Consequently, new therapeutic modalities are urgently required to overcome chemoresistance observed in ovarian cancer patients. IGF-1R expression was evaluated immunohistochemically in tissue microarray blocks constructed from 1,200 ovarian cancer samples collected from three medical institutions. CONCLUSION: Evidence accumulates suggesting that the insulin/insulin growth factor (IGF) pathways could play a good therapeutic target in various cancers, including ovarian cancer.

Co-Existing Ovarian Mucinous Cystadenocarcinoma with Mature Cystic Teratoma: A Rare Case Report.

Background: Mature cystic teratoma is the most common benign germ cell ovarian tumor. Malignant transformation is uncommon. The pathology is mostly composed of squamous cell carcinoma. Mucinous cystadenocarcinoma should be differentiated between malignant transformation and the coincidental occurrence. Case Report: A case of an early stage mucinous ovarian cancer co-existing with mature cystic teratoma at the same ovarian side was reported. A 57-year-old woman presented with incidental palpable pelvic mass for two weeks. Right ovary consisted of multiloculated cyst and mature cystic teratoma. The patient underwent an exploratory laparotomy for a large ovarian cyst evaluation. Mucinous ovarian cancer was diagnosed as FIGO stage IC3 after operation. Histopathology report showed mucinous cystadenocarcinoma and mature cystic teratoma of the right ovary. There was no additional abdominal abnormality. Immunohistochemistry staining supported the diagnosis of metastatic adenocarcinoma of colon or intestinal type of mucinous ovarian cancer. Further investigation for locating other primary cancer site was then performed. The result was negative. The intestinal-type mucinous ovarian cancer co-existing with mature cystic teratoma of the right ovary was the final histopathological reading. The patient was then started on carboplatin/paclitaxel combination chemotherapy for 6 cycles after surgery. The patient showed complete remission at the end of the chemotherapy treatment. Conclusion: This was a rare case of mucinous ovarian cancer co-existing with mature cystic teratoma. Clinical acumen, immunochemistry staining and metastatic survey investigation played important roles for the final diagnosis.

Heterotopic ossification in appendiceal mucinous neoplasms: clinicopathological characteristics of 3 cases.

Heterotopic bone formation is a very rare event in the gastrointestinal tract including in the appendix. Here we report three cases of heterotopic ossification in appendiceal mucinous neoplasms, one occurring in an appendiceal mucinous cystadenoma, another in a low-grade appendiceal mucinous neoplasm, and the third occurring in an appendiceal mucinous adenocarcinoma. The clinicopathologic characteristics of these three present cases and two previously reported cases are discussed in detail. The mechanism of heterotopic ossification in appendiceal mucinous neoplasm is still unclear, but mucin extravasation and subsequent calcification may be predisposing events.

[Mucinous cystic liver tumors: diagnosis and surgical treatment]. / Mutsinoznye kistoznye opukholi pecheni: diagnostika i khirurgicheskoe lechenie.

AIM: To optimize diagnostics and treatment of cystic liver tumors. MATERIAL AND METHODS: The analysis included outcomes of 46 patients with liver cystic tumors. RESULTS AND DISCUSSION: The use of abdominal Doppler-sonography (37 patients), abdominal contrast-enhanced CT (44 patients) and MRI of abdominal cavity with MR-cholangiography (24 patients) defined radiological semiotics of cystic liver diseases. The most important features of cystic tumors are intraluminal septums with blood flow (82% of patients), solid component (6.8%), daughterly cysts (11.3%), as well as biliary hypertension (39.2% of patients). Research of oncomarkers (CEA, SA 19-9, AFP) in 40 patients showed increased level of SA 19-9 only in case of cystadenocarcinoma and intraductal papillary mucinous neoplasm of biliary type. Benign and malignant cystic tumors had increased contents of oncomarkers in all cases. Surgical treatment was used in 42 patients. Extended liver resections were performed in 10 (23.8%) patients, atypical and anatomical resections (removal of less than 3 segments) - in 31 (73.8%) patients. In one case we applied cryoablation of CA in segment I of the liver in view of invasion into the wall of inferior vena cava and hepatoduodenal ligament. In 2 cases surgery was carried out laparoscopically. Also robot-assisted technique was used in 3 patients. Immunohistochemical study was performed in 22 (44.8%) patients. The diagnosis of CAC and biliary type of IPMN was confirmed in case of high expression of CK7, SK19, MUC1, S100p, SDH2, p53 antibodies. Cystadenomas were associated with moderate expression of ER, PR and p53 antibodies by stroma and CK7, SK19, CDX2, MUC1, S100p antibodies by epithelium. CONCLUSION: There are considerable difficulties of differential diagnosis of liver cystic tumors. Therefore, the use of single algorithm of diagnostics and treatment is necessary to confirm accurately the diagnosis at the perioperative stage. Cystic tumor is more likely to be assumed in women with solitary cyst in segment IV of liver. If the diagnosis is suspected or confirmed anatomical liver resection with complete tumor removal is necessary to prevent the recurrence.

Krukenberg carcinoma metastasized from stomach resembling mucinous cystadenocarcinoma of the ovary.

The ovaries are common site of metastasis in a variety of primary neoplasms. Multiple tumors such as breast, lung, and pancreas have been reported to metastasize to the ovary, however; the colon and stomach are the most common primary cancer sites that of ovarian metastasis. An ovarian mass mostly originates from its self-tissue, but sometimes it can be a metastasis of a gastrointestinal system tumor. Such cases are often misdiagnosed as primary ovarian cancers. A 42-year-old woman was admitted to our hospital with pelvic pain. She had a history of her complaints for two months. Bilateral large ovarian mass was detected in transvaginal ultrasound. Laparotomy was performed, the pathologist suggested inspection of the stomach after the frozen section analysis; therefore, an irregular mass on the stomach was detected. The general surgeon was attended to the operation, and an inoperative stomach tumor was reported by the general surgeon. After that due to the partial obstruction of jejunum, a gastrojejunostomy was performed. It is in fact difficult to distinguish between metastatic mucinous carcinomas and primary mucinous carcinomas of the ovary, due to the similar appearance of as cystic tumors on gross examination. The clinicians should be aware of the likely concomitant gastrointestinal system tumor when a large and bilaterally mass was detected on physical examination. This case also reminds that a systemic examination is necessary even if the large ovarian tumors suspicious of primary malignancy were noticed.

Expression of c-myc and mutation of the KRAS gene in patients with ovarian mucinous tumors.

We examined the expression of c-myc and mutations in the KRAS gene in ovarian mucinous tumors to explore the pathogenesis of these tumors and the feasibility of targeted gene therapy. Expression of c-myc protein and mutations in the KRAS gene in 24 cases of ovarian mucinous cystadenoma, 46 cases of ovarian borderline mucinous cystadenoma, and 46 cases of ovarian mucinous cystadenocarcinoma were detected using the immunohistochemistry PV-9000 2-step method and polymerase chain reaction-restriction fragment length polymorphism. The positive expression rates of c-myc in ovarian mucinous cystadenoma, borderline mucinous cystadenoma, and cystadenocarcinoma were 0, 39.1, and 65.2%, respectively (P < 0.01), while the mutation rates in KRAS were 0, 39.1 and 13.0%, respectively. The mutation rate of the borderline group was significantly higher, while rates in the other 2 groups were similar (P > 0.05). c-myc was not correlated with clinical stage, pathological grade, or age of patients with ovarian mucinous cystadenocarcinoma or borderline mucinous cystadenoma (P > 0.05), but was correlated with tumor size (P < 0.05). Mutations in KRAS were not correlated with clinical stage or tumor size in patients with borderline mucinous cystadenoma (P > 0.05), whereas it was correlated with age (P < 0.05). In borderline mucinous cystadenoma, c-myc expression and KRAS mutations were not correlated (P > 0.05). c-myc is involved in the formation of ovarian borderline mucinous cystadenoma and mucinous cystadenocarcinoma, and the KRAS gene may contribute to the formation of borderline mucinous cystadenoma.