Case 300: Ruptured Mucinous Cystadenoma of the Pancreas.

History Part one of this case appeared 4 months previously and may contain larger images. A 40-year-old woman presented to the outpatient department of our hospital with a 2-year history of abdominal pain, which had worsened in the past few days. There were no other constitutional symptoms; in particular, there was no weight loss or loss of appetite. The serum amylase and serum lipase levels were always within normal limits, even during the current episode. There was no history of pancreatitis, alcohol abuse, drug use, or trauma. The patient was evaluated at an outside clinic 2 years ago and underwent imaging, including US and dedicated pancreatic CT, which revealed a complex multiseptated noncalcified pancreatic cystic lesion. After CT, the patient underwent endoscopic US, which showed the lesion was suspected to be an infected parasitic cyst; fine-needle aspiration and cytology were not attempted due to the risk of iatrogenic rupture. The patient was advised to undergo surgical resection but declined the procedure and was lost to follow-up for 2 years before her current visit to our facility. On clinical examination, there were no clinically important findings, aside from mild to moderate pain on deep palpation and some shifting dullness that was suggestive of ascites. The patient always remained hemodynamically stable. US-guided ascitic fluid analysis was performed, which revealed amylase levels of 869 IU/L (normal range, 4-234 IU/L). Considering prior CT and endoscopic US reports, the patient was further evaluated with a pancreatic MRI protocol for lesion characterization and to explain the new-onset abdominal pain.

MRI is useful to suggest and exclude malignancy in mucinous cystic neoplasms of the pancreas.

OBJECTIVES: To evaluate the value of MRI in differentiating benign (b-MCN) and malignant (m-MCN) MCN. European guidelines suggest that certain mucinous cystic neoplasms (MCN) of the pancreas can be conservatively managed. METHODS: A retrospective single-center study of consecutive patients with resected MCN. MRIs were independently reviewed by two readers blinded to the pathological results. The authors compared b-MCN (i.e., mucinous-cystadenoma comprising high-grade dysplasia (HGD)) and m-MCN (i.e., cystadenocarcinoma). RESULTS: Sixty-three patients (62 women [98%]) with 63 MCN (6 m-MCN, 2 HGD) were included. m-MCN tumors had a tendency to be larger than b-MCN (median 86 [25-103] vs. 45 [17-130] mm, p = .055). The combination of signal heterogeneity on T2-weighted imaging, wall thickness ≥ 5 mm, the presence of mural nodules ≥ 9 mm, and enhancing septa had an area under the ROC curve of 0.97 (95% CI 0.91-1.00) for the diagnosis of m-MCN. A total of 24 (37%), 20 (32%), 10 (16%), 5 (8%), and 4 (6%) out of 63 MCNs showed 0, 1, 2, 3, and 4 of these features, respectively. The corresponding rate of m-MCN was 0%, 0%, 10%, 20%, and 100%, respectively, with a good-to-excellent inter-reader agreement. Patterns with a high NPV for m-MCN included an absence of enhancing septa or walls (NPV 97% and 100%, respectively), wall thickness < 3 mm (NPV 100%), and no mural nodules (NPV 100%). CONCLUSIONS: A combination of 4 imaging features suggests malignant MCN on MRI. On the other hand, visualization of a thin non-enhancing wall with no mural nodules suggests benign MCN. KEY POINTS: • A heterogenous signal on T2-weighted MRI, a ≥ 5-mm-thick wall, mural nodules ≥ 9 mm, and/or enhancing septa suggest malignant MCNs. • A thin non-enhancing wall with no mural nodules suggests benign MCNs. • MRI should be performed in the pre-therapeutic evaluation of MCN to help determine the therapeutic strategy in these patients.

Ovarian Cystadenomas: Growth Rate and Reliability of Imaging Measurements.

OBJECTIVES: To evaluate the growth rate of benign ovarian cystadenomas and the degree of variability in ultrasound measurements. METHODS: Two independent retrospective cohorts of women found to have benign cystadenomas at surgery were identified. To assess growth rate, ultrasounds on women in a community-based health system were reviewed and the growth rate was determined based on the maximum reported size dimension using a mixed effect model. To assess measurement variability, two radiologists independently measured presurgical adnexal imaging findings for women in a tertiary care referral setting. Interobserver, intra-observer, and intermodality (cine clip versus still images) variability in measurements was determined using correlation coefficients (CC) and Bland-Altman analysis, with the proportion of measurements varying by more than 1 cm calculated. RESULTS: For growth rate assessment, 405 women with 1412 ultrasound examinations were identified. The median growth rate was 0.65 cm/year with mucinous cystadenomas growing faster at 0.83 cm/year compared to 0.51 cm/year for serous cystadenomas (median test P < .0001). To evaluate measurement variability, 75 women were identified with 176 ultrasound studies. The within-subject standard deviations for ultrasound measurements were 0.74 cm for cine clip images and 0.41 cm for static images, with 11% of measurements overall differing by more than 1 cm. CONCLUSIONS: Cystadenomas grow on average 0.65 cm/year, which is similar in magnitude to the inherent error observed in measurement on ultrasound, suggesting that repeat ultrasound at intervals of longer than a year will often be needed to accurately assess growth if a cyst represents a benign cystadenoma.

Mucinous cystadenoma of the liver with pathological-radiological correlation.

The paper presents a pathological-radiological correlation of the manifestation of mucosal cystadenoma with ovarian stroma of the liver with examination and correlation with the new stroma nomenclature and differential diagnostic dilemmas of radiologists and pathologists.

Mucinous cystadenoma arising from a pancreatic heterotopia.

Mucinous pancreatic cystadenoma (MCA) is a premalignant lesion usually located in the body and tail of the pancreas, characteristically in females in their fifties and sixties. The definitive diagnosis relies on the presence of columnar mucin-producing epithelium and ovarian-type stroma. MCA arising from a pancreatic heterotopia (PH) has been rarely reported.

An intrapancreatic bronchogenic cyst simulating a mucinous cystadenoma. A case report.

We present the case of a 61-year-old male with a long-term epigastric mass and pain, high CA 19.9 levels and no weight loss. A computerized tomography was performed and a solid-cystic pancreatic mass was observed. The lesion measured 10 x 8 cm with well-defined margins, a macroscopic calcification and an enhanced solid component.

Dilation of the biliary tract secondary to intrahepathic biliary mucinous cystadenoma with ovarian stroma.

We present the case of a 55-year-old female with no history of interest and asymptomatic, who was admitted to perform studies due to findings of an abdominal ultrasound. A dilated left intrahepatic bile duct and a segment of the common hepatic duct, the proximal bile duct, was identified with irregular thickening of the wall, with an increased caliber (12 mm). A cystic lesion of 6 x 5.5 x 8 cm was also identified in the left liver lobe, with multiple septa. Computed tomography (CT) and magnetic resonance imaging (MRI) showed overlapping findings. Endoscopic retrograde cholangiopancreatography (ERCP) identified a filling defect in the common hepatic duct-left intrahepatic duct, which was not pulled with a Fogarty balloon, although it passed through it.

Mucocoele of the appendix: A case report.

Mucinous cystadenoma is a rare tumour of the appendix. It accounts for only 0.4% of the gastrointestinal tract malignancies and is reported rarely in the literature. Therefore, surgical management is not yet established. Here we report the case of a 65-year-old female who presented with a dragging sensation and a feeling of a mass in the right iliac fossa. Her computed tomography (CT) suggested formation of an abscess in the parietal peritoneum. She was scheduled for laparotomy and upon exploration, a mass was found arising from the tip of the retroperitoneal appendix. The whole of the appendix was studded with mucoid material. Right hemicolectomy was performed and histopathology of the appendix showed mucinous cystadenoma with no evidence of malignant changes. The recovery was uneventful and the patient was discharged on the fourth post-operative day. The unusual presentation of retroperitoneal pseudomyxoma without any intraperitoneal pathology prompted us to report this case.

[A case of mucinous cystadenoma of the pancreas changed from multilocular to unilocular with cyst in cyst structure with an 8-year follow-up].

A 57-year-old woman presented with multilocular cysts like a bunch of grapes, 30mm in diameter, in the tail of the pancreas. The number of cysts has increased, and each one had grown. Eventually, they turned into a unilocular cyst with a cyst in the cyst structure of about 50mm in diameter. Laparoscopic distal pancreatectomy was performed, and the resected specimen was diagnosed with mucinous cystadenoma. We report the rare morphological change in this case and consider the mechanism of its occurrence based on pathological considerations.

Pancreatic Hydatid Cyst Misdiagnosed as Mucinous Cystadenoma: CT and MRI Findings.

Isolated hydatid cysts of the pancreas are rare lesions, even in endemic regions. In this report, we present the case of a 76-year-old patient who was admitted to our clinic with a diagnosis of a cystic lesion in the tail of the pancreas. On preoperative computed tomography (CT) and magnetic resonance (MR) examination, the cyst was characterized as a mucinous cystadenoma. A laparoscopic distal pancreatectomy followed. A histopathological examination revealed a large hydatid cyst in the tail of the pancreas.

Differential diagnosis of pancreatic serous cystadenoma and mucinous cystadenoma: utility of textural features in combination with morphological characteristics.

BACKGROUND: Texture analysis of medical images has been reported to be a reliable method for differential diagnosis of neoplasms. This study was to investigate the performance of textural features and the combined performance of textural features and morphological characteristics in the differential diagnosis of pancreatic serous and mucinous cystadenomas. METHODS: We retrospectively reviewed 59 patients with pancreatic serous cystadenoma and 32 patients with pancreatic mucinous cystadenoma at our hospital. A three-dimensional region of interest (ROI) around the margin of the lesion was drawn manually in the CT images of each patient, and textural parameters were retrieved from the ROI. Textural features were extracted using the LifeX software. The least absolute shrinkage and selection operator (LASSO) method was applied to select the textural features. The differential diagnostic capabilities of morphological features, textural features, and their combination were evaluated using receiver operating characteristic (ROC) analysis, and the area under the receiver operating characteristic curve (AUC) was used as the main indicator. The diagnostic accuracy based on the AUC value is defined as follows: 0.9-1.0, excellent; 0.8-0.9, good; 0.7-0.8, moderate; 0.6-0.7, fair; 0.5-0.6, poor. RESULTS: In the differential diagnosis of pancreatic serous and mucinous cystadenomas, the combination of morphological characteristics and textural features (AUC 0.893, 95% CI 0.816-0.970) is better than morphological characteristics (AUC 0.783, 95% CI 0.665-0.900) or textural features (AUC 0.777, 95% CI 0.673-0.880) alone. CONCLUSIONS: In conclusion, our preliminary results highlighted the potential of CT texture analysis in discriminating pancreatic serous cystadenoma from mucinous cystadenoma. Furthermore, the combination of morphological characteristics and textural features can significantly improve the diagnostic performance, which may provide a reliable method for selecting patients with surgical intervention indications in consideration of the different treatment principles of the two diseases.

Mucinous Neoplasms of the Ovary: Radiologic-Pathologic Correlation.

Mucinous neoplasms of the ovary account for 10%-15% of ovarian neoplasms. They may be benign, borderline, or malignant. The large majority are benign or borderline, accounting for 80% and 16%-17%, respectively. Mucinous neoplasms of the ovary most commonly affect women in their 20s to 40s. The clinical manifestation is nonspecific, but most mucinous ovarian neoplasms manifest as large unilateral pelvic masses. At gross pathologic analysis, mucinous ovarian neoplasms appear as large multiloculated cystic masses. The contents of the cyst loculi vary on the basis of differences in internal mucin content. At histologic analysis, mucinous ovarian neoplasms are composed of multiple cysts lined by mucinous epithelium, often resembling gastrointestinal-type epithelium. Imaging evaluation most commonly includes US and/or MRI. The imaging findings parallel the gross pathologic features and include a large, unilateral, multiloculated cystic mass. The cyst loculi vary in echogenicity, attenuation, and signal intensity depending on the mucin content. Mucinous neoplasms of the ovary are staged surgically using the FIGO (International Federation of Gynecology and Obstetrics) staging system. Primary treatment is surgical, with adjuvant chemotherapy considered in the uncommon case of mucinous carcinoma with extraovarian disease. Since most mucinous ovarian neoplasms are benign or borderline, the overall prognosis is excellent.

A Prospective Study on Contrast-Enhanced Endoscopic Ultrasound for Differential Diagnosis of Pancreatic Cystic Neoplasms.

BACKGROUND AND AIMS: To determine the value of contrast-enhanced endoscopic ultrasound (CE-EUS) for differentiation of pancreatic cystic neoplasms (PCNs). METHODS: From April 2015 to December 2017, 82 patients were enrolled in this study. All patients were confirmed to have PCNs by surgical pathology. Prior to surgery, all patients underwent fundamental B-mode EUS (FB-EUS) and CE-EUS, 65 of whom underwent computed tomography (CT) and 71 of whom underwent magnetic resonance imaging (MRI). The enhanced mode data of PCNs were recorded. The diagnostic accuracy of CE-EUS in classifying PCNs was compared with that of CT, MRI and FB-EUS. The ability of CE-EUS to identify PCNs was evaluated by comparing the enhanced mode of PCNs. RESULTS: There was a significant difference between benign and malignant lesions in enhanced mode (P = 0.017). The enhanced modes of benign lesions were mostly type II and type III, while those of malignant lesions were type 0, type I, and type IV. The sensitivity, specificity, and accuracy of type 0, type I, and type IV enhanced mode as the diagnostic criterion for malignant lesions were 80%, 65.3%, and 67.1%, respectively. CE-EUS demonstrated greater accuracy in identifying PCNs than did CT, MRI, and FB-EUS (CE-EUS vs. CT: 92.3% vs. 76.9%; CE-EUS vs. MRI: 93.0% vs. 78.9%; CE-EUS vs. FB-EUS: 92.7% vs. 84.2%). CONCLUSION: Compared with CT, MRI, and FB-EUS, CE-EUS is better at differentiating PCNs. CE-EUS is expected to be another important imaging technique for the diagnosis of PCNs.

Giant hepatobiliary cystadenoma: clinic-pathological findings.

Hepatic mucinous cystic neoplasms represent a challenging pathology due to their very low frequency, insidious presentation and unclear demography due to the limited cases reported to date. Surgical treatment is mandatory when possible to prevent recurrence and malignant transformation. The case presented herein has a peculiarity, mainly an increased level of CA 19-9 which has not been previously reported.

[Value of Magnetic Resonance Imaging Texture Feature Analysis in the Differential Diagnosis between Pancreatic Serous Cystadenoma and Mucinous Cystadenoma].

Objective To investigate the difference of tumor textures presented on T1-weighted image(T1WI) and T2-weighted image(T2WI) between pancreatic serous cystadenoma and mucinous cystadenoma. Methods Subjects including 24 patients with serous cystadenoma and 20 patients with mucinous cystadenoma who were treated in Hainan Branch of Chinese PLA General Hospital were enrolled in this study.The texture analysis was performed on T1WI and T2WI,and the texture parameters included angular second moment,contrast,correlation,inverse difference moment(IDM),and entropy.Independent sample t-test and Mann-Whitney U test were performed for the between-group comparison,the regression model was established by Binary Logistic regression analysis,and receiver operating characteristics curve(ROC) was drawn.Results The contrast and IDM of T1WI and the contrast,correlation,and IDM of T2WI showed significant differences between serous cystadenoma and mucinous cystadenoma(T1WI:Pangular second momont=0.714,Pcontrast=0.003,Pcorrelation=0.069,PIDM=0.004,Pentropy=0.818;T2WI:Pangular second momont=0.122,Pcontrast=0.000,Pcorrelation=0.000,PIDM=0.024,and Pentropy=0.081).The area under the ROC curve was 0.736-0.846 for the positive texture variables,and the area under the ROC curve was 0.879 for the variables in the model of Logistic regression.Binary Logistic regression analysis demonstrated that the contrast was a specific imaging variable for the differential diagnosis between serous cystadenoma and mucinous cystadenoma.Conclusion The texture analysis of T1WI and T2WI may be a simple and effective tool in the differential diagnosis between pancreatic serous cystadenoma and mucinous cystadenoma.

Clinical and ultrasound features of benign, borderline, and malignant invasive mucinous ovarian tumors.

OBJECTIVE: To compare clinical and sonographic features of benign, borderline, and malignant invasive mucinous ovarian tumors (MOTs). MATERIALS AND METHODS: Retrospective observational multicenter study comprising 365 women (mean age: 46.1 years) with a histologically confirmed benign, borderline or malignant invasive MOT. Clinical data (patient's age, patient's complaints), tumor markers (CA-125 and CA-1 9.9), and sonographic data (tumor size, bilaterality, morphology -unilocular, multilocular, unilocular-solid, multilocular-solid and solid-, and IOTA color score) were reviewed and compared among these three groups. Women with ultrasound evidence on intra-abdominal disease spread were excluded. RESULTS: Three hundred seventy-eight MOTs (14 women had bilateral lesions) were analyzed. Histologically, 287 tumors were benign, 51 were borderline, and 40 were malignant. No difference in patient's mean age was observed. Women with borderline or invasive tumors were less frequently asymptomatic. Tumors were larger in case of invasive lesions. Borderline and invasive tumors showed solid components and exhibited IOTA color score 3 or 4, more frequently than benign lesions (p < 0.001). However, the authors discovered that 16 out of 51 (31.4%) of borderline tumors and six out of 40 (15.0%) of invasive cancers had no solid components and a color score 1 or 2, and were considered as a benign lesion by the sonolo- gist. On the other hand, 96 out of 287 (33.4%) benign mucinous cystadenoma exhibited solid components and/or a color score of 3 or 4. CONCLUSIONS: In spite of statistical differences, the authors observed significant overlapping in ultrasound features among benign, borderline, and invasive ovarian mucinous tumors that renders a difficult accurate preoperative discrimination among these lesions.

Chronic immunosuppression does not potentiate the malignant progression of mucinous pancreatic cystic lesions.

BACKGROUND: Premalignant mucinous pancreatic cystic lesions (mPCLs) are increasingly identified. AIMS: In this study, we aim to assess the effect of selected immunosuppressive therapies on the progression of mPCLs, including side-branch intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. METHODS: We performed a retrospective cohort study of patients with mPCLs diagnosed over a 24-year period who received chronic immunosuppression. Controls were matched on age at cyst diagnosis (±11 yrs) and cyst size (±8 mm). Measured outcomes included increase in cyst size, development of "worrisome features" as defined by consensus guidelines, progression to malignancy, and rate of surgical resection. RESULTS: 39 patients (mean age 60 yrs) with mPCLs were on immunosuppression. Leading indications for immunosuppression were solid organ transplant (n = 14), inflammatory bowel disease (n = 6), and rheumatoid arthritis (n = 5). 33% were on biologics, 77% on antimetabolites and 79% on multiple medications. Mean cyst size increased from 12.6 mm to 17.8 mm over a median of 16.5 months. 6 patients elected for surgical resection, and none ultimately developed malignancy. 26 cases with follow-up were matched to control subjects, with no significant differences among cases and controls in initial cyst size (12.8 mm vs 11.9 mm, P = 0.69), mean size increase (6.9 mm vs 5 mm, P = 0.47), follow-up interval (24.3 months vs 21.5 months, P = 0.44). No significant differences in the rate of worrisome features, malignancy, or surgical resection. CONCLUSIONS: Patients with mPCLs exposed to immunosuppressive medications did not have higher rates of malignancy or development worrisome features in the short term. This suggests that patients with mPCLs can be initiated or maintained on these agents without changes to surveillance practices.

Diffusion-Weighted Magnetic Resonance Imaging in Distinguishing Between Mucin-Producing and Serous Pancreatic Cysts.

OBJECTIVE: The aim of this study was to evaluate the feasibility and reproducibility of diffusion-weighted imaging in distinguishing between mucin-producing and serous pancreatic cysts. METHODS: Forty-four pancreatic cysts (43 patients, 27 women; mean age, 57 years; 26 mucin-producing cysts, 18 serous cysts) that underwent histological examination or cyst analysis after diffusion-weighted magnetic resonance imaging were retrospectively reviewed. Three blinded readers independently evaluated signal intensity and apparent diffusion coefficient (ADC). Intraobserver and interobserver agreements were calculated. Fisher exact test and Welch t test were used to compare signal intensity and ADC values, respectively, with pathological results. Receiver operating characteristic analysis was used to determine diagnostic accuracy of various thresholds for ADC. A P value less than 0.05 was considered statistically significant. RESULTS: Mean ADC values of the mucin-producing cysts were 3.26 × 10, 3.27 × 10, and 3.35 × 10 mm/s for the 3 readers, respectively. Mean ADC values of the serous cysts were 2.86 × 10, 2.85 × 10, and 2.85 × 10 mm/s for the 3 readers, respectively. Differences in ADC values between the 2 cyst groups were 12.4%, 12.9%, and 14.8% for the 3 readers, respectively (P < 0.001). Intraobserver and interobserver agreement was excellent. A threshold ADC of 3 × 10 mm/s resulted in correct identification of cysts in 77% to 81% of cases, with sensitivity and specificity ranging between 84% and 88% and 66% and 72%, respectively. CONCLUSIONS: Diffusion-weighted imaging may be a helpful tool in distinguishing between mucin-producing and serous pancreatic cysts.

A Novice User of Pediatric Emergency Point-of-Care Ultrasonography Avoids Misdiagnosis in a Case of Chronic Abdominal Distention.

A 13-year-old adolescent girl with chronic abdominal distention was referred to the pediatric emergency department after the outpatient workup suggested moderate ascites. Point-of-care ultrasonography performed by the emergency physicians ruled out ascites, instead demonstrating a well-circumscribed cystic mass subsequently identified as an ovarian mucinous cystadenoma.