Cystic Tumor Research Articles

Identifying Tumor Microenvironment Biomarkers in Adherent and Cystic Vestibular Schwannomas.

A subset of vestibular schwannomas (VSs), including cystic tumors, have higher postoperative morbidity because of the presence of adhesions between the tumor, facial nerve (FN), and brainstem. We identify tumor microenvironment (TME) biomarkers to better classify these tumors and predict the degree of tumor adherence. Retrospective case series. Tertiary skull base referral center. Adult patients with cystic and solid VS matched in tumor size who underwent surgical resection were included. Expressions of seven biomarkers of extracellular matrix remodeling and tumor immune response were quantified via immunohistochemistry. The distribution of CD45+ immune cells was evaluated in intratumoral and perivascular compartments. The degree of tumor adherence was categorized as none, adherent to FN, or adherent to both FN and brainstem. Twenty-eight patients were included. Cystic VSs were significantly more adherent than solid VSs ( p = 0.02). Patients with adherent VS had shorter duration of symptoms and were more likely to undergo subtotal resection. In solid tumors, matrix metalloproteinase (MMP)-2 expression ( p = 0.02) and CD163+ macrophage infiltration ( p = 0.007) were correlated with tumor size. Linear discriminant analyses (LDAs) demonstrated MMP-2, MMP-14, CD80, CD163, and perivascular CD45 to be individually predictive of the degree of tumor adherence (all p < 0.05), with perivascular CD45 being the best independent predictor ( p = 0.005). An LDA model including these biomarkers demonstrated 100% accurate discrimination of all three levels of tumor adherence ( p = 0.04). Adherent VS have a distinct proinflammatory TME characterized by elevated MMP expression, enrichment of tumor-associated macrophages, and perivascular immune cell infiltration.

Endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: a comprehensive review.

Advancements in diagnostic radiology have amplified the incorporation of these techniques into routine clinical practice. Concurrently, the frequency of incidentally identifying pancreatic cystic lesions (PCLs) has surged. PCLs encompass diverse categories contingent upon their origin. Among them, branch duct-intraductal papillary mucinous neoplasms (BD-IPMN) and mucinous cystic neoplasms (MCN) are categorized as mucinous cystic lesions that have malignant potential. Even solid neoplasms occasionally show cystic degeneration. Therefore, precise differential PCL diagnosis is crucial to optimize clinical management strategies and detect malignant transformations. Endoscopic ultrasound (EUS) affords comprehensive visualization of the pancreas with high-resolution ultrasound, complemented by fine-needle aspiration (FNA) under real-time EUS guidance, which is a minimally invasive procedure for obtaining pathological samples. This synergy has established EUS and EUS-FNA as vital procedures in the management of PCLs, enabling differentiation of PCLs. Cyst fluid analysis has played a pivotal role in deciding the optimal management strategy. The efficacy of cytological analysis is limited by scant cytologic material. The "string sign" test evaluates fluid viscosity, and its simplicity warrants initial consideration. Amylase and tumor markers, such as CEA, have been studied, but they yield varied sensitivity and specificity. Glucose and genetic mutations (KRAS, GNAS) exhibit promise, while comprehensive genomic profiling underscores genetic insights. Through-the-needle biopsy and needle-based confocal laser endomicroscopy also show high diagnostic yield. EUS-FNA, however, entails risks like infection and needle tract seeding, emphasizing the need for proper utilization. Pancreatic cyst fluid analysis augments diagnostic accuracy and informs clinical decisions, making it a valuable adjunct to imaging.

Diagnóstico y tratamiento de los quistes hepáticos. Utilidad de los marcadores tumorales intraquísticos (CEA y CA 19.9.)

IntroductionTo decide treatment of hepatic cysts diagnosis between simple hepatic cyst (SHC) and cystic mucinous neoplasm (CMN). Radiological features are not pathognomonic. Some studies have suggested the utility of intracystic tumor markers. MethodsRetrospective analysis of our prospective database including patients treated due to symptomatic SHC from 2003 to 2021. The aim of the study was to evaluate the results of treatment of symptomatic SHC and the usefulness of the determination of intracystic “carcinoembryonic antigen” (CEA) and “carbohydrate antigen” CA 19.9. ResultsFifty patients diagnosed and treated for symptomatic SHC were included. In 15 patients the first treatment was percutaneous drainage. In 35 patients the first treatment was laparoscopic fenestration. Four patients were diagnosed of premalignant or malignant liver cystic lesions (MCN, IPMN, and lymphoma B); three of them required surgery after initial fenestration and pathological diagnosis.Median CEA and CA 19.9 were 196μg/L and 227.321U/mL, respectively. Patients with malignant or premalignant pathology did not have higher levels of intracystic tumor markers. Positive predictive value was 0% for both markers, and negative predictive value was 89% and 91%, respectively. ConclusionValues of intracystic tumor markers CEA and CA 19.9 do not allow distinguishing simple cysts from cystic liver neoplasms. The most effective treatment for symptomatic simple liver cysts is surgical fenestration. The pathological analysis of the wall of the cysts enables the correct diagnosis, allowing to indicate a surgical reintervention in cases of hepatic cyst neoplasia.

Cystic partially differentiated nephroblastoma in an 18-month-old girl: a case report

Introduction and importance: Cystic partially differentiated nephroblastoma (CPDN) is a rare cystic tumor that affects the kidney. It has a low potential for malignancy. It usually presents as an abdominal mass. It may be difficult to confirm the diagnosis of CPDN without a histopathological study. Case presentation: The authors report a case of an 18-month-old girl with abdominal distention, which was noticed by her parents. An abdominal computed tomography scan showed a large multilocular cystic mass arising from the lower pole of the left kidney. A left total nephrectomy was performed. Immature blastemal elements without evidence of malignant cells were observed on histological analysis. Conclusion: The authors report a case of an 18-month-old girl with CPDN managed by total nephrectomy. CPDN should be considered in the differential diagnosis of patients with cystic renal lesions. The authors would also like to affirm that partial or total nephrectomy should be done in all cases of CPDN and other cystic renal tumors.

Pancreatic cystic neoplasm: A retrospective analysis from a tertiary center

Pancreatic cystic neoplasm: A retrospective analysis from a tertiary center

Radiomics Based on Contrast-Enhanced Ultrasound Images for Diagnosis of Pancreatic Serous Cystadenoma.

The purpose of the study was to develop and validate a radiomics model by using contrast-enhanced ultrasound (CEUS) data for pre-operative differential diagnosis of pancreatic cystic neoplasms (PCNs), especially pancreatic serous cystadenoma (SCA). Patients with pathologically confirmed PCNs who underwent CEUS examination at Chinese PLA hospital from May 2015 to August 2022 were retrospectively collected. Radiomic features were extracted from the regions of interest, which were obtained based on CEUS images. A support vector machine algorithm was used to construct a radiomics model. Moreover, based on the CEUS image features, the CEUS and the combined models were constructed using logistic regression. The performance and clinical utility of the optimal model were evaluated by area under the receiver operating characteristic curve (AUC), sensitivity, specificity and decision curve analysis. A total of 113 patients were randomly split into the training (n=79) and test cohorts (n=34). These patients were pathologically diagnosed with SCA, mucinous cystadenoma, intraductal papillary mucinous neoplasm and solid-pseudopapillary tumor. The radiomics model achieved an AUC of 0.875 and 0.862 in the training and test cohorts, respectively. The sensitivity and specificity of the radiomics model were 81.5% and 86.5% in the training cohort and 81.8% and 91.3% in the test cohort, respectively, which were higher than or comparable with that of the CEUS model and the combined model. The radiomics model based on CEUS images had a favorable differential diagnostic performance in distinguishing SCA from other PCNs, which may be beneficial for the exploration of personalized management strategies.

Acute pancreatitis in intraductal papillary mucinous neoplasm: a single-center retrospective cohort study with systematic review and meta-analysis

BackgroundIntraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas arising from abnormal papillary proliferation of ductal epithelial cells, and is a precancerous lesion of pancreatic malignancy. This study aimed to evaluate associations between acute pancreatitis (AP) and histologic subtypes of IPMN.MethodsIn the clinical study, patients with IPMN confirmed by surgical resection specimens at our institute between 2009 and 2021 were eligible for inclusion. Associations and predictive accuracy of AP on the presence of HGD were determined by logistic regressions. In addition, a systematic review and meta-analysis was conducted through literatures upon search in PubMed, Embase, CENTRAL, China National Knowledge Infrastructure (CKNI), and Wanfang database, up to June, 2023. Pooled effects of the associations between AP and HGD and intestinal epithelial subtype subtype, shown as odds ratios (ORs) with 95% confidence intervals (CIs), were calculated using random effects model.ResultsThe retrospective cohort study included 47 patients (32 males, 15 females) diagnosed with IPMN at our center between 2009 and 2021, including 11 cases with AP (median 62 years) and 36 cases (median 64.5 years) without. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AP in predicting HGD were 78.7%, 57.1%, 82.5%, 36.4%, and 91.7%, respectively. Univariate logistic regression analysis showed that AP group had greater odds of presence of HGD (OR: 6.29,95% CI: 1.14–34.57) than non-AP group. Meta-analysis of five case-control studies in the literature included 930 patients and showed that AP-IPMN patients had higher odds for HGD (OR: 2.13, 95% CI 1.38–3.29) and intestinal epithelial subtype (OR: 5.38, 95% CI: 3.50–8.27) compared to non-AP IPMN.ConclusionsAP is predictive of malignancy in patients with IPMN.

Inadequacy of the eighth edition of the American Joint Committee on Cancer pancreatic cancer staging system for invasive carcinoma associated with premalignant lesions in the pancreas: an analysis using the National Cancer Database

BackgroundInvasive carcinomas arising from premalignant lesions are currently staged by the same criteria as conventional pancreatic ductal adenocarcinoma. MethodsClinicopathologic information and survival data were extracted through a thorough search of histology codes from National Cancer Database (2006–2016). A total of 723 patients with invasive intraductal papillary mucinous neoplasm and mucinous cystic neoplasm were analyzed. ResultsThe median age was 67 years, and 351 patients (48.5%) were male. There were 212 (29.3%), 232 (32.1%), 272 (37.6%), and 7 (1.0%) patients with T1, T2, T3, and T4 classification. Extrapancreatic extension (EPE) was present in 284 (39.3%). Age (HR = 1.504, 95% CI 1.196–1.891), R1 or R2 resection (HR = 1.585, 95% CI 1.175–2.140), and EPE (HR = 1.598, 95% CI 1.209–2.113) were independent prognostic factors for overall survival. Size criteria did not significantly affect survival. The median survival was 115.9 months for patients without EPE, compared to 34.2 months for those with EPE. EPE discriminated survival better than tumor size. DiscussionThe T classification of the eighth edition AJCC staging system is not adequate for invasive carcinomas associated with premalignant lesions of the pancreas. They merit a separate, dedicated staging system that uses appropriate prognostic factors.

Mucocele of the Anorectal Pouch: Mucinous Cystic Neoplasm with Low-Grade Dysplasia Simulating Low- Grade Appendiceal Mucinous Neoplasm (LAMN)

Abstract Introduction/Objective We present the second case of colonic mucocele with dysplasia. To date, only five cases of colonic mucocele have been reported, all in the setting of a pouch or bypass, with only one of them showing dysplasia. The exceptional rarity of the lesion provides unique insight into etiology of mucocele. Methods/Case Report A 44-year-old male with complex surgical history including pull-through procedure for imperforate anus at birth, and later proctectomy with end colostomy due to poor anorectal function, presented with worsening low back pain radiating down to his left leg. An abdominal CT scan revealed a large pelvic cyst, causing compressive neuropathy. Multilocular cystic mass (17.5 cm) was resected, which was partially filled with mucinous material. Mucin was not seen on the cyst surface. On microscopic examination, the cyst was largely denuded however was partially lined by markedly attenuated ano-rectal type mucosa and focally by dysplastic glandular epithelium. Similar to LAMN, pools of acellular mucin dissecting stromal tissues were noted, associated with degenerative changes, calcifications and fibrosis. No invasive carcinoma or high-grade dysplasia was seen. Given the lack of extra- cystic mucin or evidence of overt malignancy, it was reported as mucinous cystic neoplasm with uncertain malignant potential. The patient has been followed for 16 months without evidence of recurrence or peritoneal disease. Results (if a Case Study enter NA) NA Conclusion Extended stasis within a bowel segment appear to contribute to the development of mucoceles. The blind-ended anatomy of the appendix renders it highly susceptible to this phenomenon, explaining the relatively high incidence of LAMN. Conversely, such prolonged stasis rarely occurs elsewhere in colon unless a pouch or bypassed segment is surgically created, particularly placing patients with a complex surgical history at the highest risk. Therefore, close follow-up is indicated in this patient group to screen for mucocele that may progress to develop dysplasia and mucinous neoplasm.

Pediatric craniopharyngiomas: magnetic resonance imaging assessment for hypothalamus-pituitary axis dysfunction and outcome prediction.

In adamantinomatous craniopharyngiomas, tumor topographical categories, cystic component volume, and magnetic resonance signal intensity may impact prognosis. To identify magnetic resonance imaging (MRI) variables associated with pituitary-hypothalamic axis dysfunction and predictive of outcome in children with cystic adamantinomatous craniopharyngiomas. We evaluated 40 preoperative MRIs of adamantinomatous craniopharyngiomas to classify tumor topography, volume, and signal intensity of the cystic components and peritumoral edema. Volumes and normalized signal intensity minimum values were extracted from coronal T2-weighted images (nT2min). Radiological variables were compared to pituitary-hypothalamic axis dysfunction-related clinical data and surgical outcomes. Adamantinomatous craniopharyngiomas were categorized into five topographic classes (12 patients, sellar-suprasellar; seven patients, pseudo-intraventricular; six patients, strict intraventricular; 14 patients, secondary intraventricular; one patient, not strict intraventricular). All cases exhibited a predominant (30 patients, 80%) or total (10 patients, 20%) cystic tumor component and displayed low nT2min percentage values compared to cerebrospinal fluid (42.3% [interquartile range 28.4-54.6%]). Significant associations between tumor topographic classes and pituitary dysfunction (P<0.001), andbetween peritumoral edema and hypothalamic dysfunction (P<0.001) were found. Considering extent of surgical removal and tumor relapse, volume of the cystic tumor component displayed a positive correlation (P=0.002; r=0.48; P=0.02; r=0.36), while nT2min intensity values exhibited a negative correlation (P=0.01; r= - 0.40; P=0.028; r= - 0.34). Severe hypothalamic-pituitary axis dysfunction is associated with tumors along the pituitary stalk and peritumoral edema. Tumor invasion of the third ventricle, tight adherence to the hypothalamus, larger volumes, and lower nT2min intensity of the tumor cystic component are independent predictors of extent ofadamantinomatous craniopharyngioma excision and recurrence.

Glucose and lactate levels are lower in EUS-aspirated cyst fluid of mucinous vs non-mucinous pancreatic cystic lesions

BackgroundDistinguishing mucinous (M) pancreatic cystic neoplasms (PCNs) from non-mucinous (NM) is challenging but crucial. Low intracystic glucose level has shown diagnostic tool promise, however further investigation is needed to understand metabolic processes. AimsTo compare the diagnostic accuracy of intracystic glucose and CEA levels in a large cohort and explore lactate levels as potential marker. MethodsPCNs≥15 mm which underwent EUS-fine needle aspiration were prospectively enrolled. Glucose, CEA and lactate levels were measured. Diagnostic accuracy for M-PCN diagnosis was evaluated using surgical/cytology reports or multidisciplinary evaluations. Results169 PCNs were included (64 % M-PCNs). Median intracystic glucose was significantly lower in M-PCNs (1 mg/dL) compared to NM-PCNs (101 mg/dL); mean intracystic CEA was significantly higher in M-PCNs (152.5 ng/mL) compared to NM-PCNs (0.3 ng/mL). ROC curve analysis revealed best glucose cut-off ≤58 mg/dL (accuracy 93.5 %) and CEA cut-off >2.5 ng/mL (accuracy 90.5 %) for M-PCNs. Intracystic lactates were significantly lower in M-PCNs correlating directly with glucose. Single glucose dosage evidenced best diagnostic accuracy respect markers combination. ConclusionIntracystic glucose demonstrated high diagnostic utility for M-PCNs differentiation, surpassing CEA. Lactate levels correlated with glucose, suggesting their uptake by M-PCNs cells. These findings contribute to a better metabolic landscape understanding glucose use as diagnostic marker.

A nonsense mutation in VHL causing Von Hippel-Lindau syndrome in a large Chinese family—a genetic study of familial neoplastic disease

Von Hippel-Lindau (VHL) syndrome is a multi-organ neoplastic disease characterized by highly vascular and cystic tumors in the central nervous system (CNS), retina, and visceral lesions, which are mainly caused by germline mutations in VHL. We aimed to detect novel mutations in VHL gene in families with VHL. Here, a large consanguineous four-generation family with variant phenotypes of VHL syndrome was recruited, and its molecular genetics were tested via Sanger sequencing. And various tools and databases were used to predict the variant pathogenicity, frequency, and protein function. Genetic investigation detected a c.351G > A nonsense mutation in VHL that altered the downstream reading frame and created a premature TGA stop signal, resulting in severely truncated pVHL (p.Trp117Ter). This mutation is absent from most public databases, and functional prediction bioinformatic tools demonstrated that this residue is conserved and that this variant is highly likely to be deleterious. The c.315G > A nonsense mutation in VHL is the causal mutation of this kindred that may lead to clear familial aggregation of VHL syndrome because of the dysfunction of the truncated pVHL.

Diagnosis and treatment of hepatic cysts. Usefulness of intracystic tumor markers (CEA and CA 19.9.)

IntroductionTo decide treatment of hepatic cysts diagnosis between simple hepatic cyst (SHC) and cystic mucinous neoplasm (CMN). Radiological features are not patognomonic. Some studies have suggested the utility of intracystic tumor markers. MethodsRetrospective analysis of our prospective database including patients treated due to symptomatic SHC from 2003 to 2021. The aim of the study was to evaluate the results of treatment of symptomatic SHC and the usefulness of the determination of intracystic “carcinoembryonic antigen” (CEA) and “carbohydrate antigen” CA 19.9. Results50 patients diagnosed and treated for symptomatic SHC were included. In 15 patients the first treatment was percutaneous drainage. In 35 patients the first treatment was laparoscopic fenestration. Four patients were diagnosed of premalignant or malignant liver cystic lesions (MCN, IPMN, lymphoma B); three of them required surgery after initial fenestration and pathological diagnosis.Median CEA and CA 19−9 were 196 μg/L and 227.321 U/mL respectively. Patients with malignant or premalignant pathology did not have higher levels of intracystic tumor markers. Positive predictive value was 0% for both markers, and negative predictive value was 89% and 91% respectively. ConclusionValues of intracystic tumor markers CEA and CA 19−9 do not allow distinguishing simple cysts from cystic liver neoplasms. The most effective treatment for symptomatic simple liver cysts is surgical fenestration. The pathological analysis of the wall of the cysts enables the correct diagnosis, allowing to indicate a surgical reintervention in cases of hepatic cyst neoplasia.

HPB O01 HemopatchTM – A Viable Means of Preventing Post-Operative Pancreatic Fistula, A Multi-Institutional Review

Abstract Background Perioperative complications post distal pancreatectomy can be myriad. One of the most common is pancreatic fistula (POPF), with an incidence that can range widely. Many techniques are employed to prevent POPF but these are mainly equivocal. Methods We conducted a retrospective review of a prospectively maintained multi-institutional pancreatic resection database of patients who underwent surgery between 01/01/2018 and 31/12/2022. Cohorts were divided into those who had a HemopatchTM applied to the pancreatic stump and those without. Demographics, POPF Grade A and Grade B/C, peak drain amylase after day 3, complications, and 30-day mortality were analyzed. Statistical analysis was conducted using SPSS. Chi-squared and T-tests were employed with a p-value of &amp;lt;0.05 deemed significant. Results Demographics between the two groups were similar. Mucinous cystic neoplasms and pancreatic adenocarcinoma accounted for the majority of indications for resection. Through the use of HemopatchTM a statistically significant reduction in Grade A POPF was seen (39% vs 63%, p-value 0.04). Grade B/C POPF approached but did not reach statistical significance in difference (6% vs 18%, p-value 0.07). Peak drain amylase was 7989 IU/L in the cohort who did not have a Hemopatch applied while in the cohort who did there was a mean of 1818 IU/L (p-value 0.05). Conclusions The routine use of HemopatchTM is a safe adjunct in distal pancreatectomies. It renders a statistically significant reduction in Grade A POPF. For Grade B/C POPF it approaches but does not meet the threshold for significance. Routine use is advocated while larger prospective trials are undertaken.

HPB P54 First Reported Case of Primary Serous Cystadenocarcinoma of the Spleen

Abstract Background Tumours of the spleen are uncommon, and the majority are metastases from primary malignancies in other organs. The two main subdivisions of primary malignancies of the spleen are lymphoid and non-lymphoid. Primary splenic cystadenocarcinomas are extremely rare, and only tumours of the mucinous subtype have been recorded. The spleen usually exhibits secondary infiltration from primary cystadenocarcinomas in other organs such as the ovaries and pancreas. Methods We present the case of an elderly white female who was found to have an incidental splenic tumour. This showed interval increase in size on serial imaging and was confirmed to be a complex mass with a cystic component on MRI. After MDT discussion and further investigations, including FDG-PET, EUS and diagnostic laparoscopy, she underwent a distal pancreatectomy, partial gastrectomy and splenectomy for a presumed tail of pancreas adenocarcinoma. Results The splenic hilum contained a large partly cystic tumour conglomerate measuring up to 5.8cm in maximum dimension, which contained thick, dark red, gelatinous material. It was well-circumscribed and demarcated from the rest of the splenic parenchyma, and the distal pancreas appeared to be uninvolved. Histology showed low columnar to cuboidal cells with moderate to patchy marked nuclear pleomorphism, and no cytoplasmic mucin was identified. The tumour had a predominantly papillary and focal tubular architecture, with hierarchical branching of papillae. The neoplastic cells stained positive for CK7, ER and WT1 expression and negative for CK20 and CA. Conclusions Histological and immunohistochemical analyses were consistent with the first recorded case in the literature of primary serous cystadenocarcinoma of the spleen, which we believe developed through malignant transformation of a benign epidermoid cyst. This is the commonest type of true cysts of the spleen and one which has tumorigenic potential, being able to undergo metaplasia and dysplasia. The patient remains well as per her latest follow-up with no evidence of recurrence or metastases. However, given the rarity of splenic cystadenocarcinomas, uncertainty remains on the long-term prognosis and optimal management of such cancers, including adjuvant treatment options.

A case report of huge pancreas mucinous cystic neoplasm during pregnancy: How doctors think.

Pancreas mucinous cystic neoplasm (PMCN) is uncommon, and its occurrence during pregnancy is rare. The management of PMCN during pregnancy, including diagnosis and surgical timing, is a great challenge. A nontender epigastric mass of the upper abdomen was detected by palpation in a 35-year-old woman, gravida 2, para 1, during the 36th week of gestation. She was referred to our institution for further evaluation. Magnetic resonance imaging (MRI) showed a multilocular cystic mass in the body and tail of the pancreas (16.7/12.1/17.6 cm), well-circumscribed with a hyper signal on T2-weighted MRI images. The diagnosis of a pancreatic cyst, probable mucinous, was established. The patient was informed of the possibilities of malignancy, rapid growth, and rupture of the tumor. After a laparotomy and cesarean section, a large cystic tumor was discovered adherent to the pancreas, spleen, mesocolon, and retroperitoneum. The spleen was preserved since there was no evidence of invasion. According to macroscopic examinations, the tumor measured 18 cm was filled with a dark yellow-brownish mucinous fluid and did not appear to communicate with the pancreatic ducts. After six months of follow-up, there were no signs of recurrence in the patient. PMCN may need to be surgically resected in cases characterized by malignancy risk during pregnancy. As female sex hormones may influence the behavior of PMCN during pregnancy, surgical timing should be determined based on the stage of pregnancy, malignancy status, and condition of the mother and fetus.

MiR-200b categorizes patients into pancreas cystic lesion subgroups with different malignant potential

Extracellular vesicles (EV) carry their cargo in a membrane protected form, however, their value in early diagnostics is not well known. Although pancreatic cysts are heterogeneous, they can be clustered into the larger groups of pseudocysts (PC), and serous and mucinous pancreatic cystic neoplasms (S-PCN and M-PCN, respectively). In contrast to PCs and S-PCNs, M-PCNs may progress to malignant pancreatic cancers. Since current diagnostic tools do not meet the criteria of high sensitivity and specificity, novel methods are urgently needed to differentiate M-PCNs from other cysts. We show that cyst fluid is a rich source of EVs that are positive and negative for the EV markers CD63 and CD81, respectively. Whereas we found no difference in the EV number when comparing M-PCN with other pancreatic cysts, our EV-based biomarker identification showed that EVs from M-PCNs had a higher level of miR-200b. We also prove that not only EV-derived, but also total cyst fluid miR-200b discriminates patients with M-PCN from other pancreatic cysts with a higher sensitivity and specificity compared to other diagnostic methods, providing the possibility for clinical applications. Our results show that measuring miR-200b in cyst fluid-derived EVs or from cyst fluid may be clinically important in categorizing patients.

RADT-46. STEREOTACTIC RADIOSURGERY FOR CYSTIC AND SOLID INTRACRANIAL HEMANGIOBLASTOMAS: A SINGLE-INSTITUTION RETROSPECTIVE SERIES

Abstract INTRODUCTION Intracranial hemangioblastoma is a rare neoplasm that poses significant challenges in clinical management. Hemangioblastomas are characterized by unique radiological features into cystic or solid tumors. Out study aims to evaluate the role of SRS in the management of cystic and solid hemangioblastomas in a single institution setting. METHODS We conducted a retrospective analysis of clinical and radiological outcomes of patients with intracranial hemangioblastomas treated with CyberKnife SRS at our institute between 1998 and 2023. The follow-up data were available for 93 intracranial hemangioblastomas in 23 patients. Ten (43.5%) patients presented with 23 (25.6%) cystic hemangioblastomas, while 13 (56.5%) patients had 70 (75.3%) solid hemangioblastomas at the time of SRS treatment. The median age was 36 years and the median tumor volume accounted for 0.43 cc. The SRS was administered with the median single-fraction equivalent dose (SFED) of 20 Gy at the 77% of the median isodose line. RESULTS At a one-year follow-up, 11 initially solid hemangioblastomas developed cystic formation, resulting in a total of 34 (36.6%) cystic hemangioblastomas and 59 (63.4%) solid hemangioblastomas across 13 and 10 patients, respectively. Among these, 84.6% exhibited peritumoral edema prior to the onset of cystic formation. For 37 solid hemangioblastomas accompanied by peritumoral edema, SRS was administered before cystic transformation, remaining solid throughout the latest follow-up. Over a median follow-up period of 59 months (range: 3-260), 6 (17.6%) cystic and 13 (22%) solid hemangioblastomas progressed. The 5-year local tumor control (LTC) rate for intracranial hemangioblastomas was 84.7%, with 97% and 76.9% in cystic and solid lesions, respectively. CONCLUSION Our study illustrates the largest single-institutional long-term retrospective analysis of intracranial hemangioblastomas treated with SRS to date. Early SRS treatment at the time of edema may prevent cystic hemangioblastoma development and provides durable treatment outcomes for patients with both cystic and solid hemangioblastomas in long-term.

Application of a pyramid pooling Unet model with integrated attention mechanism and Inception module in pancreatic tumor segmentation.

The segmentation and recognition of pancreatic tumors are crucial tasks in the diagnosis and treatment of pancreatic diseases. However, due to the relatively small proportion of the pancreas in the abdomen and significant shape and size variations, pancreatic tumor segmentation poses considerable challenges. To construct a network model that combines a pyramid pooling module with Inception architecture and SE attention mechanism (PIS-Unet), and observe its effectiveness in pancreatic tumor images segmentation, thereby providing supportive recommendations for clinical practitioners. A total of 303 patients with histologically confirmed pancreatic cystic neoplasm (PCN), including serous cystic neoplasm (SCN) and mucinous cystic neoplasm (MCN), from Shanghai Changhai Hospital between March 2011 and November 2021 were included. A total of 1792 T2-weighted imaging (T2WI) slices were used to build a CNN model. The model employed a pyramid pooling Inception module with a fused attention mechanism. The attention mechanism enhanced the network's focus on local features, while the Inception module and pyramid pooling allowed the network to extract features at different scales and improve the utilization efficiency of global information, thereby effectively enhancing network performance. Using three-fold cross-validation, the model constructed by us achieved a dice score of 85.49±2.02 for SCN images segmentation, and a dice score of 87.90±4.19 for MCN images segmentation. This study demonstrates that using deep learning networks for the segmentation of PCNs yields favorable results. Applying this network as an aid to physicians in PCN diagnosis shows potential for clinical applications.

Dermoid Cyst of the Mesentery of the Jejunum Following Appendectomy: A Clinical Case

Mesenteric cysts and cystic mesenteric tumors are very rare abdominal growths. They may be localized all over the mesentery, from the duodenum to the rectum, however, they are mostly found in the ileum and right colon mesentery. There are several classifications of these formations, among which the one based on histopathologic features including 6 groups has been most commonly used: 1) cysts of lymphatic origin--lymphatic (hilar cysts) and lymphangiomas; 2) cysts of mesothelial origin--benign or malignant mesothelial cysts; 3) enteric cysts; 4) cysts of urogenital origin; 5) dermoid cysts; and 6) pseudocysts-infectious or traumatic etiology. A dermoid cyst is a benign, epithelial-lined cavitary lesion composed of ectoderm and mesoderm that can arise anywhere in the body, with a tendency to develop in midline structures. In 20% - 45% of cases, accompanying diseases that were not previously clinically manifested can be diagnosed during emergency interventions, requiring additional surgical interventions for their correction. The aim of the study is to demonstrate the successful treatment experience of a dermoid cyst of the mesentery of the jejunum, detected after traditional appendectomy. Clinical case: A mother brought her 9-year-old son, V., to the emergency department of the Kursk Regional Children’s Clinical Hospital with complaints of moderate-intensity pain in the right iliac region, multiple episodes of vomiting, and fever. Ultrasound features indicative of destructive appendicitis and peritonitis. In an emergency situation, after preoperative preparation, a traditional appendectomy was performed under intravenous anesthesia, using the Volkovich-Dyakonov approach. The postoperative period was uneventful. Moderate infiltration was observed on the control abdominal ultrasound examination, in the intestine (presumably the small intestine) in the right half of the abdominal cavity, with a solid formation measuring 27*33 mm, producing a dense acoustic shadow. On the 7th day after the initial intervention, a revision of the abdominal organs was performed. The loop of the jejunum with the formation was brought out into the wound. The capsule above the formation was dissected: the formation of bone density, when the capsule is separated, resembles a fecal stone in structure, considering the localization - a dermoid cyst. Step-by-step enucleation of the cyst was performed. The postoperative wound was tightly sutured in layers.