Benign Cystic Lesions Research Articles

A RARE CASE OF MUCINOUS CYSTADENOCARCINOMA OF LIVER PRESENTING AS HYDATID CYST

Hepatobiliary cystadenocarcinoma is a very rare cystic tumor that arises in the liver or, less frequently, in the extrahepatic biliary system mostly seen in elderly patients. It has been shown to arise in congenital liver cysts, bile ducts, biliary cystadenoma, in the context of bro- polycystic disease and in the hepatoduodenal ligament. In the present case report, we describe a case of rare entity of hepatobiliary cystadenocarcinoma presented in a 36 year old male patient presented to opd with complaints of pain abdomen in right side of upper abdomen since 2 months. Main concern of this case report is preoperative imaging is imprecise and frequently misdiagnosed as benign cystic lesions and delays in treatment.

Late Developed Unusual Nasal Involvement of Postoperative Maxillary Cyst Following Maxillary Sinus Augmentation: A Case Report

Postoperative maxillary cyst (POMC) is a benign expansive cystic lesion of the maxilla generally related to invasive maxillary surgeries or trauma. POMC can also develop after maxillary sinus augmentation (MSA), but many dentists are not well-aware of such complication of MSA. A 56-year-old male patient had undergone bilateral MSA. After 18 years, the patient reported painless swelling on the left palate. On the panoramic radiographs, no specific findings were found, but a large unilocular lesion was detected at the medial side of the previous augmentation of the left maxillary sinus on cone-beam computed tomographic examination. The lesion expanded medially and downward to destruct the medial wall of the maxillary sinus and palatal bone. Medial expansion of the lesion also reached the nasal septum and inferior meatus. Due to the extent and the location, the lesion was hard to manage using an intraoral surgical approach. The patient was then referred to an otolaryngologist in a university hospital. Endoscopic marsupialization was performed under general anesthesia. Previous augmentation and dental implants could be maintained during the marsupialization. The removed tissue sample revealed respiratory epithelium with inflammatory cell infiltration, confirming that the lesion was a postoperative maxillary cyst (POMC). There has been no recurrence of POMC to date. POMC is a rare postoperative complication of maxillary sinus augmentation, but clinicians should be aware of the possibility of POMC and the necessity of regular radiological monitoring.

Pseudotumor Associated with Dall-Miles Cable Breakage Following Revision Total Hip Arthroplasty: A Case Report

A pseudotumor is a benign granulomatous or cystic lesion associated with the deposition of metal debris in joint arthroplasties. To the best of our knowledge, this is the first report on a pseudotumor caused by the breakage of the Dall-Miles cable grip system, a multifilament cable used to fix the trochanteric osteotomy in revision total hip arthroplasty. This rare case demonstrates that pseudotumor formation can be caused by various types of orthopedic materials and implant components. When encountering a palpable mass around an orthopedic implant, a pseudotumor should be considered along other differential diagnoses. To treat pseudotumors and also prevent recurrence, its complete resection and sufficient removal of orthopedic materials are necessary.

Optimal bone biopsy route to the proximal femur evaluated by computed tomography-based finite element modeling

IntroductionThe proximal femur (PF) is one of the most common locations of benign cystic lesions. A fracture after bone biopsy is a rare but severe complication. However, the risk of fracture after biopsy of this lesion has not been well-studied. Computed tomography (CT)-based finite element (FE) modeling estimates the elastic modulus and compressive strength enables fracture prediction. This study investigated strength of PF after biopsy by CT-FE modeling and determined the optimum biopsy level and size. Materials and methodsSix male bone tumor patients’ (15–38 years) total femur CT data (slice thickness, 0.8–1.0 mm) of the healthy side were obtained. Three different cylindrical bone defect (BD) diameters (10, 15, and 20 mm) were set on the lateral surface of PF at the following levels: level 1, insertion of the gluteus minimums; level 2, lower end of the greater trochanter (GT); level 3, origin of the vastus lateralis; level 4, center of the lesser trochanter (LT); and level 5, lower end of LT using Mechanical Finder software (version 8.0). Virtual loads were applied with incremental increases of 100 N until fracture occurred and the fracture load (FL) was evaluated. ResultsFor BD with a diameter of 15 and 20 mm, there was a significant difference in the decrease of the mean FL, with an average of 22% at level 4 and 5, and 33%–44% at levels 3 to 5, respectively. At level 1 and 2, no significant decrease in the mean FL was observed regardless of the diameter of BD. ConclusionBiopsies at level 1 and 2 showed no significant decrease in bone strength. However, biopsy at level 1 may contaminate the GT bursas. Therefore, biopsy at level 2 (lower end of GT) can avoid contamination and minimize the effect on bone strength.

Orbital Lymphangioma: A Case Report and Review of Management Modalities

Background: Generally presents in childhood, orbital lymphangioma is an uncommon unencapsulated vascular malformation of the lymphatic system. These benign cystic lesions represent 1%-4% of all orbital masses and may appear after an upper respiratory infection or minor trauma. Because of its nature, the management can be challenging and depends on the clinical presentation. We report an 8-year-old boy with orbital lymphangioma presented with acute proptosis. Then, we discuss different features of this disorder plus its management Case Presentation: An 8-year-old boy was presented with sudden left eye proptosis. He had normal visual acuity and color vision without ocular pain or diplopia. An infiltrative and diffused intraconal plus extraconal mass was detected in orbital computed tomography. Contrast-enhanced MRI revealed a multilobulated infiltrative heterogeneous lesion with fluid-fluid levels. The diagnosis was made on imaging, and he went under treatment with an oral corticosteroid. The symptoms were entirely resolved, and no recurrence occurred during the follow-up. There are several surgical and nonsurgical therapies for orbital lymphangioma. Still, the priority is conservative management, such as sclerotherapy (including OK-432, doxycycline, sodium tetradecyl sulfate, etc.), bleomycin, carbon dioxide laser, systemic corticosteroids, and so on. Conclusions: In most cases, the current imaging methods make a noninvasive diagnosis of orbital lymphangioma possible. Conservative management should be considered the first treatment.

S1499 Large Pancreatic Cyst in Von Hippel-Lindau (VHL) Syndrome Causing Bile Duct Obstruction

Introduction: Von Hippel-Lindau (VHL) syndrome is a rare autosomal inherited disorder characterized by the development of multiple tumors, the most common of which is renal cell carcinoma, hemangioblastomas, pheochromocytomas, and solid and cystic tumors of the pancreas. Morbidity and mortality in VHL are more commonly related to renal and central nervous system pathologies. Extrahepatic biliary obstruction secondary to pancreatic cysts is rare in patients with VHL. We present a case of extrahepatic biliary obstruction secondary to pancreatic cysts in a patient with a history of VHL syndrome successfully managed endoscopically. Case Description/Methods: 35-year-old woman with history of VHL and course complicated by clear cell renal cell carcinoma status post partial nephrectomy, cervical/medullary/fourth ventricle hemangioblastomas status post resection, and serous cystic pancreatic adenoma status post distal pancreatectomy and splenectomy with subsequent development of insulin-dependent diabetes mellitus type 2, presented with three days of right upper quadrant abdominal pain. MR Cholangiopancreatography revealed the residual pancreas was completely replaced by multiple cystic lesions with a dominant cyst in the head of the pancreas measuring 6.2 cm causing mass effect on the portal vein and mid to distal common bile duct with resultant intrahepatic, extrahepatic biliary ductal dilatation, and gallbladder distension. Using EUS with fine-needle biopsy of the cyst was done. Intraprocedural cholangiogram during ERCP revealed 14mm dilation of proximal extrahepatic biliary duct and non-opacification of the distal extrahepatic bile duct in the region of the pancreatic head, consistent with a stricture. CBD brushings were sent for cytology and a straight plastic biliary stent was successfully deployed across the stricture. After the endoscopic procedure, the patient demonstrated clinical improvement. Discussion: The pancreatic manifestation of VHL can present as a cystic, solid, or combined lesion. The management is complex because of the challenge in the differentiation of benign cystic lesions from malignant lesions. This case highlights the fact that pancreatic involvement leading to acute biliary obstruction, although uncommon, can occur in patients with VHL syndrome. Conservative management with endoscopic biliary stent placement and endoscopic surveillance (for secondary manifestations - portal hypertension) may be helpful in these patients, however eventual surgical management may be needed.Figure 1.: (Top left) Stricture/obstruction in ERCP, (Bottom left) EUS with biopsy, (Right) MRI showing cyst, CBD, and distended gallbladder.

Clinically Benign Cystic Lesions of the Lateral Neck: Road to Malignant Discoveries

Solitary cystic neck lesions as the only presenting feature in adult patients may present diagnostic challenges as the aetiology may be malignant or non-malignant entities. Investigation is usually through radiology and tissue sampling. Subsequent diagnosis of malignancy requires thorough exploration for localization of primary tumour for complete treatment. We report 2 cases of solitary cystic neck lesion subsequently diagnosed as malignancy. First case is a 70-year-old man presented clinically with left branchial cyst. Excision of the cyst revealed papillary thyroid carcinoma. He underwent total thyroidectomy, central and left neck dissection despite no obvious nodule on physical examination or ultrasound. Histologically, no tumour was found on the thyroid or lymph node specimen. The second case is a 48-year-old man presented with painless right neck swelling. Excision showed squamous cell carcinoma arising in a right branchial cyst. Extensive examination did not show any other mass within the head and neck region. However, one year later his right neck swelling recurred. Histological examination confirmed metastatic squamous cell carcinoma to the neck lymph node. He underwent bilateral tonsillectomy and modified radical neck dissection following the finding of occult malignancy. Primary tumour was identified at the tonsil. Malignant cystic neck lesions are not uncommon. Solitary, painless lateral neck cyst in an adult warrant careful and detailed work-up. Aspiration of lateral neck cyst is an effective primary investigation tool prior to embarking on more costly or invasive examination.International Journal of Human and Health Sciences Supplementary Issue-2: 2021 Page: S9

Hsa_circ_0074491 regulates the malignance of cholesteatoma keratinocytes by modulating the PI3K/Akt pathway by binding to miR-22-3p and miR-125a-5p: An observational study.

Cholesteatoma is a benign cystic lesion that can continue to grow like a tumor. Circular ribonucleic acid (RNA) hsa_circ_0074491 (circ_0074491) has been reported to be down-regulated in cholesteatoma tissues. However, the role and regulatory mechanism of circ_0074491 in the growth of cholesteatoma are unclear.The expression of circ_0074491, microRNA (miR)-22-3p, and miR-125a-5p in cholesteatoma tissues was detected by quantitative real-time polymerase chain reaction. The proliferation, cell cycle, apoptosis, migration, and invasion of cholesteatoma keratinocytes were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, plate clone, flow cytometry, or transwell assays. Several protein levels were examined by western blotting. The targeting relationship between miR-22-3p or miR-125a-5p and circ_0074491 was verified via dual-luciferase reporter and RNA pull-down assays.We observed the downregulation of circ_0074491 in cholesteatoma tissues. Furthermore, circ_0074491 knockdown facilitated cell proliferation, migration, invasion, and repressed cell apoptosis in cholesteatoma keratinocytes. Circ_0074491 was verified as a decoy for miR-22-3p and miR-125a-5p in cholesteatoma keratinocytes. Both miR-22-3p and miR-125a-5p silencing reversed the impacts of circ_0074491 silencing on proliferation, apoptosis, migration, and invasion of cholesteatoma keratinocytes. Also, circ_0074491 knockdown activated the PI3K/Akt pathway in cholesteatoma keratinocytes via miR-22-3p and miR-125a-5p.Circ_0074491 played a suppressive role in cholesteatoma through inactivating the PI3K/Akt pathway via binding to miR-22-3p and miR-125a-5p, which provided a novel evidence for the involvement of circRNA in the development of cholesteatoma.

The Clinical Importance of IL-6, IL-8, and TNF-α in Patients with Ovarian Carcinoma and Benign Cystic Lesions.

The exact pathogenesis and influence of various cytokines in patients with ovarian lesions remains unclear. Hence, this study aimed to investigate whether IL-6, IL-8, and TNF-α could be considered as new useful markers for diagnosis of ovarian cancer. 63 women diagnosed with ovarian cancer (OC) and 53 patients with benign ovarian cystic (BOC) lesions were included in this study. Serum levels of IL-6, IL-8, and TNF-α were measured using ELISA. Statistical comparisons were made using the Mann–Whitney U test and all correlations were evaluated by Spearman’s ranks. The serum IL-8 and TNF-α concentration measured in the OC Group was significantly higher than in the BOC Group (p < 0.05). The cutoff level of IL-8 and TNF-α in the serum was set at 4.09 ng/mL and 2.63 ng/mL, respectively, with the sensitivity and specificity of 70% and 96% for IL-8 and 85.7% and 79.3% for TNF-α (p < 0.0001). These results suggest that IL-8 and TNF-α are useful biomarkers for predicting the malignant character of lesions of the ovary. The present study highlighted the importance of measuring the cytokines such as IL-8 and TNF-α in patients with ovarian lesions in predicting the clinical outcome.

Masson’s tumor of the neck: A rare case report

Masson’s tumor is a rare, benign, vascular lesion, commonly affecting the head, neck and peripheries. It is usually asymptomatic and can be confused with malignant tumors. We report a 56-year-old male who presented with a solitary swelling in the right side of neck which was clinically diagnosed as a benign cystic lesion, hence complete excision of the lesion was done. Histopathology demonstrated the papillary proliferation of endothelial cells, in favour of Masson’s tumor.

Gastric Leiomyoma Misdiagnosed as a Left Cystic Adrenal Tumor

Gastrointestinal leiomyomas often occur in the esophagus, colon, and rectum, but are very rare in the stomach. The patient was referred to Jeju national university medical center for the treatment of a left adrenal tumor diagnosed 5 years ago. She had a long history of repeated left flank pain, nausea, and abdominal distension for the last few years. Annual follow-up computed tomography scan showed a no changed 5×5.5-cm sized multiloculated left adrenal cystic lesion. Laboratory tests revealed that the basal levels of plasma adrenocorticotropin, cortisol, aldosterone, renin, testosterone, adrenaline, noradrenaline, and dopamine were normal findings. The preoperative diagnosis was a left nonfunctioning adrenal neoplasm with symptom of discomfort. However, the tumor revealed as an exophytic growing leiomyoma with cystic changes of a stomach by surgery. The mass was found at the posterior wall of the fundus and about 5-cm-sized mass. Resection of the tumor was performed using laparoscopy. The pathologic diagnosis revealed a gastrointestinal leiomyoma with a benign cystic lesion lined by respiratory epithelium with an old hemorrhage and chronic gastritis. The patient had no evidence of recurrence during the 12-month follow-up. Gastric leiomyoma is unfamiliar to the usual urologists. It needs to take gastric leiomyoma into account if the left adrenal tumor is close to the stomach. Herein, we report the case of a 44-year-old woman with gastrointestinal leiomyoma misdiagnosing as a nonfunctioning adrenal tumor.

Dacryops of the lacrimal gland in an elderly woman: A case report.

IntroductionDacryops is a rare benign cystic lesion of the lacrimal gland often developing in the palpebral gland. The exact etiology of dacryops remains unclear. Diagnosis could be suspected clinically and established histopathologically. Treatment is commonly surgical.Presentation of caseWe report the case of a 75-year-old woman with past history of total conservative parotidectomy for a benign tumor 10 years ago. She presented to the Ophtalmology Department at Farhat Hached University Hospital of Sousse with a painful swelling of the left supero-external orbital angle. The patient underwent complete excision of the cyst using the conjunctival approach. Histopathological examination showed characteristic features of dacryops with foci of chronic inflammatory cell infiltrates.DiscussionDacryops is commonly seen in young adults or middle-aged individuals with a slight female preponderance. In some cases, cystic enlargement of dacryops can lead to mechanical ptosis, dystopia, limitation of extraocular movements, diplopia, and, in rare cases, blepharoptosis. However in this case, the patient was an elderly woman presenting a painless mass without ptosis. As in our case, excision using the conjunctival approach under microscope has excellent results without complications. Histopathological examination confirms the diagnosis and helps to rule out differential diagnoses.ConclusionAs reported in the present case, histopathological examination confirms clinically recognized or suspected dacryops. If untreated, dacryops may lead to ptosis, proptosis and/or dystopia. Complete excision of the cyst is often curative.

Diagnostic value of neuronal pentraxin II methylation in patients with pancreatic cancer: Meta-analysis.

Pancreatic cancer (PC) is a devasting disease of which mortality almost parallels its incidence. PC tissue may express aberrantly methylated neuronal pentraxin II (NPTX2), but it is unclear what the consequences of this are. We systematically searched PubMed, Web of Science, the Chinese National Knowledge Infrastructure (CNKI), from inception to July 15, 2020, to identify if the detection of methylated NPTX2 have sufficient sensitivity and specificity to identify PC from other benign pancreatic diseases. Majority of the studies obtained samples from pancreatic juice by endoscopy or surgery and composed of population with chronic pancreatitis, benign cystic lesion, intraductal papillary mucinous neoplasm, and healthy controls. Our results demonstrated that the diagnostic value of methylated NPTX2 is of widely various sensitivity and specificity and it shown higher specificity in differentiate PC from benign diseases. The lab method of quantitative real-time methylation-specific PCR (QMSP) has higher specificity than real-time methylation-specific PCR (MSP) in detecting the indicator. NPTX2 methylation could serve as a promising molecular biomarker for pancreatic cancer diagnosis, for its high diagnostic value in differentiating pancreatic cancer from benign pancreatic disease with the lab method. The variable sensitivity of methylated NPTX2 was multifactorial, and it must be promoted before applied as screening test in clinical practice. Furthermore, experiments on methylated NPTX2 were needed to expanded for lower the heterogeneity.

Evaluating the added benefit of CT texture analysis on conventional CT analysis to differentiate benign ovarian cysts.

We aimed to evaluate the benefit of adding CT texture analysis on conventional CT features of benign adnexal cystic lesions, especially in identifying mucinous cystadenoma. This retrospective study included patients who underwent surgical removal of benign ovarian cysts (44 mucinous cystadenomas, 32 serous cystadenomas, 16 follicular/simple cysts and 43 endometriotic cysts) at our institution between January 2015 and November 2017. The CT images were independently reviewed by an abdominal radiologist (reviewer 1) and a resident (reviewer 2). Both reviewers recorded the conventional characteristics and performed texture analysis. Based on reviewer 1's results, two decision trees for differential diagnosis were developed. Reviewer 2's results were then applied to the decision trees. The diagnostic performances of each reviewer with and without the decision trees were compared. Several conventional features and texture analysis parameters showed significant differences between mucinous cystadenomas and other benign adnexal cysts. The first decision tree selected septum number and thickness as significant features, whereas the second decision tree selected septum number and the mean values at spatial scaling factor (SSF) 0. Reviewer 1's performance did not change significantly with or without the use of the decision trees. Reviewer 2's interpretations were significantly less sensitive than reviewer 1's interpretations (p = 0.001). However, when aided by the first and second decision trees, Reviewer 2's interpretations were significantly more sensitive than reviewer 1's interpretations (86.4%, p < 0.001; 72.7%, p = 0.001). This study suggests the benefit of CT texture analysis on conventional images to differentiate mucinous cystadenoma from other benign adnexal cysts, particularly for less experienced radiologists.

Excision of Lower Lip Mucocele Using Injection of Hydrocolloid Dental Impression Material in a Pediatric Patient: A Case Report

Oral mucocele is a benign cystic exophytic lesion affecting the minor salivary gland and is especially present in pediatric patients (3% under 14 years). It is characterized by an extravasation or retention of fluid or mucus in the submucosal tissue of the minor salivary glands. Several surgical techniques have been proposed over the years, including the excision of the mucocele by using the injection of a hydrocolloid impression material in the light of the cyst to prevent the collapse of the cystic wall and solidify the lesion, resulting in a better cleavage plan. The combined clinical approach between the combination of Shira’s technique and the surgical excision of the cystic lesion results in a conservative surgical removal of the lesion. Here, we reported the removal of a labial mucocele in a 14-year-old male patient, using the injection of a hydrocolloid impression material. At a 12 months follow up, the patient showed complete healing of the surgical site, showing a pinkish lip lining mucosa without scarring or recurrence of the primary lesion. The combined therapeutic approach between Shira’s technique and surgical excision allows a safe and predictable excision of the labial mucocele, minimizing the risk of recurrence.

Efficacy of ethanol ablation as a treatment of benign head and neck cystic lesions

ObjectiveTo evaluate the efficacy and safety of ethanol ablation in the treatment of benign head and neck cystic lesions. MethodsA total of 25 patients who received ethanol ablation (EA) of head and neck cystic lesions by an otolaryngologist at a single institution between October 2017 and October 2020 were identified. Patient demographics, clinical characteristics, treatment details, and treatment outcomes at follow up visits were obtained by retrospective review of electronic medical records. Results25 patients who underwent ethanol ablation of head and neck cystic lesions were included, with a mean age of 49.1 years old (Interquartile range (IQR),32.5–65.5 years) and 12 males (47.0%). The most common cysts treated with EA were thyroglossal duct cysts (n = 8, 32.0%) and lymphoepithelial parotid cysts (n = 7, 28.0%). The mean volume prior to treatment was 10.57 mL (IQR, 1.58–8.81 mL). Mean volume following EA was 1.30 mL (range, 0.10–0.97 mL) with 74.40% cyst reduction by volume (IQR, 48.56–96.29%) (p = 0.002). The mean time to the last follow-up was 5 months (range, 3–6 months). One patient received surgery despite treatment success to obtain a definitive diagnosis of the mass. No other patients received further surgical management. The treatment success of EA, as defined by >70% volume reduction or the resolution of symptoms, was 92.0%. All patients were satisfied with the outcome and had no reported complications. ConclusionEA is an effective and safe alternative to surgery for the treatment of head and neck cystic lesions that can be performed in an outpatient setting by an otolaryngologist.

“MUCINOUS ADENOCARCINOMA OF COLON MIMICKING CYSTIC LYMPHANGIOMA: REPORT OF AN UNUSUAL PRESENTATION WITH BRIEF REVIEW OF LITERATURE.”

Retroperitoneal masses present with a diverse group of lesions; ranging from benign to malignant. These lesions can be solid or cystic, single or multiloculated, and the contents may range from serous to mucinous uid. Mucinous adenocarcinoma of retroperitoneum is rare. We present a case of retroperitoneal mucinous adenocarcinoma of colon in a 25-year-old male, mimicking a benign cystic lesion on radiology. Cytology along with histopathology helped in making a denitive diagnosis of malignancy in this case.

CYSTICERCOSIS CHEEK IN A PAEDIATRIC PATIENT – A RARE CASE

Cysticercosis cellulosae is a systemic parasitic infection caused by the larval stage of pork tapeworm, taenia solium which involve humans as either a denitive or secondary host. It is a common disease in developing countries. The cases presenting as an isolated muscle mass is an extremely rare entity and demands documentation. Herein, we present a case of healthy pediatric patient who presented with unilateral cheek swelling which on ultrasound suggested a benign cystic lesion. The diagnosis was conrmed on ne needle aspiration cytology (FNAC).

Oncocytic papillary cystadenoma of the larynx: comparative study of ten cases and review of the literature.

Oncocytic papillary cystadenomas (OPCs) of the larynx are rare benign cystic lesions that usually present as supraglottic masses arising from the laryngeal ventricles. OPCs are found in patients older than 60years, with a female predominance. Symptoms vary from asymptomatic to hoarseness, dyspnea, and dysphagia; often, they mimic a laryngocele. The treatment is surgical. Diagnosis is based on histopathologic examination. Surgical records for laryngeal masses diagnosed between 2005 and 2020 were searched retrospectively. Ten patients were identified and included in the study. OPCs predominantly occurred in women (9/10), and the mean age at presentation was 73years. Most patients (8/10) presented with hoarseness and were smokers. OPCs were localized in the ventricle in eight out of ten patients. Surgical treatment was performed in all cases, mostly using transoral endolaryngeal approach (9/10). Histopathologic examination revealed oncocytic cyst or oncocytic papillary cystadenoma (the former term being the older synonym for OPC). OPCs present a separate clinicopathologic entity, distinct from other cystic laryngeal lesions. They have a characteristic location, age and sex group, microscopic appearance, and potential for local recurrence.

Diagnostic Accuracy of MRI for Differentiation of Benign and Malignant Pancreatic Cystic Lesions Compared to CT and Endoscopic Ultrasound: Systematic Review and Meta-analysis.

Differentiation of benign and malignant pancreatic cystic lesions on MRI, computed tomography (CT), and endoscopic ultrasound (EUS) is critical for determining management. To perform a systematic review evaluating the diagnostic accuracy of MRI for diagnosing malignant pancreatic cystic lesions, and to compare the accuracy of MRI to CT and EUS. Systematic review and meta-analysis. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched until February 2020 for studies reporting MRI accuracy for assessing pancreatic cystic lesions. 1.5T or 3.0T. Methodologic and outcome data were extracted by two reviewers (AU and MA, 2 years of experience each). All studies of pancreatic cystic lesions on MRI were identified. Studies with incomplete MRI technique were excluded. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. Sensitivity/specificity was pooled using bivariate random-effects meta-analysis with 95% confidence intervals (95%CI). Pairwise-comparison of MRI to CT and EUS was performed. The impact of gadolinium-based contrast agents, mucinous lesions, and risk of bias were explored using meta-regression. MRI pooled sensitivity was 76% (95%CI 67% to 84%) and specificity was 80% (95%CI 74% to 85%) for distinguishing benign and malignant lesions. MRI and CT had similar sensitivity (P=0.822) and specificity (P=0.096), but MRI was more specific than EUS (80% vs. 75%, P < 0.05). Studies including only contrast-enhanced MRI were more sensitive than those including unenhanced exams (P < 0.05). MRI sensitivity and specificity did not differ for mucinous lesions (P=0.537 and P=0.384, respectively) or for studies at risk of bias (P=0.789 and P=0.791, respectively). MRI and CT demonstrate comparable accuracy for diagnosing malignant pancreatic cystic lesions. EUS is less specific than MRI, which suggests that, in some cases, management should be guided by MRI findings rather than EUS. 3 TECHNICAL EFFICACY STAGE: 2.