Cystic Tumor Research Articles

Anaesthesia Management for Giant Intraabdominal Tumours: A Case Series Study.

Due to a lack of randomised controlled trials and guidelines, and only case reports being available in the literature, there is no consensus on how to approach anaesthetic management in patients with giant intraabdominal tumours. This study aimed to evaluate the literature and explore the current status of evidence, by undertaking an observational research design with a descriptive account of characteristics observed in a case series referring to patients with giant intraabdominal tumours who underwent anaesthesia. Twenty patients diagnosed with giant intraabdominal tumours were included in the study, most of them women, with the overall pathology being ovarian-related and sarcomas. Most of the patients were unable to lie supine and assumed a lateral decubitus position. Pulmonary function tests, chest X-rays, and thoracoabdominal CT were the most often performed preoperative evaluation methods, with the overall findings that there was no atelectasis or pleural effusion present, but there was bilateral diaphragm elevation. The removal of the intraabdominal tumour was performed under general anaesthesia in all cases. Awake fiberoptic intubation or awake videolaryngoscopy was performed in five cases, while the rest were performed with general anaesthesia with rapid sequence induction. Only one patient was ventilated with pressure support ventilation while maintaining spontaneous ventilation, while the rest were ventilated with controlled ventilation. Hypoxemia was the most reported respiratory complication during surgery. In more than 50% of cases, there was hypotension present during surgery, especially after the induction of anaesthesia and after tumour removal, which required vasopressor support. Most cases involved blood loss with subsequent transfusion requirements. The removal of the tumor requires prolonged surgical and anaesthesia times. Fluid drainage from cystic tumour ranged from 15.7 L to 107 L, with a fluid extraction rate of 0.5-2.5 L/min, and there was no re-expansion pulmonary oedema reported. Following surgery, all the patients required intensive care unit admission. One patient died during hospitalization. This study contributes to the creation of a certain standard of care when dealing with patients presenting with giant intraabdominal tumour. More research is needed to define the proper way to administer anaesthesia and create practice guidelines.

Enlarged tumefactive perivascular, or Virchow-Robin, spaces and hydrocephalus: do we need to treat? Illustrative cases.

Perivascular spaces (PVSs) are spaces in brain parenchyma filled with interstitial fluid surrounding small cerebral vessels. Massive enlargements of PVSs are referred to as "giant tumefactive perivascular spaces" (GTPVSs), which can be classified into three types depending on their localization. These lesions are rare, predominantly asymptomatic, and often initially misinterpreted as cystic tumor formations. However, there are several reported cases in which GTPVSs have induced neurological symptoms because of their size, mass effect, and location, ultimately leading to obstructive hydrocephalus necessitating neurosurgical intervention. Presented here are three diverse clinical presentations of GTPVS. Here, the authors observed an asymptomatic case of type 1 GTPVS and two symptomatic cases of type 3 GTPVS, one causing local mass effect and the other hydrocephalus. GTPVSs are mostly asymptomatic lesions. Patients without symptoms should be closely monitored, and biopsy is discouraged. Hydrocephalus resulting from GTPVS necessitates surgical intervention. In these cases, third ventriculostomy, shunt implantation, or direct cyst fenestration are surgical options. For patients presenting with symptoms from localized mass effect, a thorough evaluation for potential neurosurgical intervention is imperative. Follow-up in type 3 GTPVS is recommended, particularly in untreated cases. Given the infrequency of GTPVS, definitive guidelines for neurosurgical treatment and subsequent follow-up remain elusive.

MED15::TFE3 fusion renal cell carcinoma with extensive cystic change: A clinicopathologic and molecular genetic study of 2 cases, with an emphasis on differential diagnosis.

TFE3-rearranged renal cell carcinomas (RCCs) harbor gene fusions between TFE3 and 1 of many partner genes. MED15::TFE3 fusion RCC is rare, often cystic, and easily misdiagnosed. This study aimed to characterize 2 cases of MED15::TFE3 fusion RCC with extensive cystic change using fluorescence in situ hybridization and targeted RNA sequencing. Both patients were young adult women aged 29 and 35 years. Radiologically, both presented with a cystic Bosniak category II renal lesion. The cysts measured 9.3 cm and 4.8 cm in greatest dimension. Both patients underwent cyst enucleation, and neither had tumor recurrence or metastasis at 26 and 6 months of follow-up, respectively. Microscopically, both tumors were entirely cystic, with thick, fibrous cystic walls lined by small clusters of cells with clear to eosinophilic cytoplasm and uniform, round nuclei with inconspicuous nucleoli. There were also small aggregations of similar clear cells within the cystic walls. Foci of basement membrane-like material depositions were noted in 1 case; calcifications were observed in both cases. Both cases demonstrated nuclear positivity for PAX8 and TFE3 and cytoplasmic staining for Melan-A; HMB45, CAIX, and CK7 were negative. Fluorescence in situ hybridization revealed that both tumors were positive for TFE3 rearrangements. RNA sequencing identified MED15::TFE3 gene fusions in both cases. The main differential diagnosis of MED15::TFE3 fusion RCC includes multilocular cystic renal neoplasm of low malignant potential and atypical renal cysts. Molecular confirmation of TFE3 fusion is essential for establishing the correct diagnosis.

Neoplastic Progression in Macroscopic Precursor Lesions of the Pancreas.

Macroscopic precursor lesions of the pancreas represent a complex clinical management problem. Molecular characterization of pancreatic cysts has helped to confirm and refine clinical and pathologic classifications of these lesions, inform our understanding of tumorigenesis in the pancreas, and provide opportunities for preoperative diagnosis. To review the pathologic classification of macroscopic cystic lesions of the pancreas: intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), intraductal oncocytic papillary neoplasms (IOPNs), and intraductal tubulopapillary neoplasms (ITPNs), and to describe our current state of understanding of their molecular underpinnings, relationship to invasive carcinomas, and implications for diagnosis and prognostication. We assessed the current primary literature and current World Health Organization Classification of Digestive System Tumours. Macroscopic cystic lesions of the pancreas are morphologically and molecularly diverse. IPMNs and MCNs share mucinous cytoplasm with papillae. MCNs are defined by ovarian-type stroma. IOPNs have granular eosinophilic cytoplasm, prominent nucleoli, and complex, arborizing papillae. ITPNs demonstrate complex, back-to-back tubules and anastomosing papillae and lack prominent intracellular mucin. IPMNs and MCNs are characterized by driver mutations in KRAS/GNAS (IPMNs) and KRAS (MCNs), with later driver events in RNF43, CDKN2A, SMAD4, and TP53. In contrast, IOPNs and ITPNs have recurrent rearrangements in PRKACA/PRKACB and MAPK-associated genes, respectively. The recurrent alterations described in cysts provide an opportunity for diagnosis using aspirated cyst fluid. Molecular characterization of IPMNs shows a striking spatial and mutational heterogeneity, challenging traditional models of neoplastic development and creating challenges to interpretation of cyst fluid sequencing results.

Current Status of Treatment among Patients with Appendiceal Tumors-Old Challenges and New Solutions?

The 5th edition of the World Health Organization (WHO) classification of tumors of the digestive system distinguishes four categories of appendiceal tumors (ATs): serrated lesions and polyps, mucinous neoplasms, adenocarcinomas, and neuroendocrine neoplasms (NENs). The differential diagnosis of ATs can be challenging in medical practice, due to their rarity and lack of data from randomized controlled trials on a large, diverse group of patients. ATs are usually noted in specimens obtained during appendectomies due to clinical acute appendicitis. In the European population, most ATs (65%) occur over the age of 50 and among women (56.8%). According to histological type, 54.6% are neuroendocrine tumors (NETs); 26.8% cystic, mucinous, and serous neoplasms; and 18.6% adenocarcinoma not otherwise specified (NOS). On pathologic analysis, most AT findings are benign lesions or small NENs that do not require further therapeutic measures. The presence of appendiceal mucinous neoplasm (AMN) can lead to pseudomyxoma peritonei (PMP). While the multimodal treatment for abdominal malignancies has evolved over the past several decades, the clinical workup and treatment of ATs remain a challenge. Therefore, this review aims to describe the diagnostic possibilities, molecular-based diagnosis, staging, differences in the treatment process, and prognostic factors associated with ATs.

Successful Surgical Management of Giant Mediastinal Teratoma – A Case Report of a Difficult Case without Any Post-Operative Complication

Introduction. Mediastinal teratoma is a rare germ cell tumor, located in anterior mediastinum and is lack of population-based study. It usually occurs in the age of 20-40 years, accounting for 15% of anterior mediastinal masses in adults and 25% of anterior mediastinal masses in children. It is frequently diagnosed accidentally on chest imaging due to its asymptomatic nature. Hereby, we presented a case of giant anterior mediastinum teratoma with complete surgical excision without any post-operative complication. This case is unique due to its uneventful result after excision. From our literature research, we successfully avoid the potential post operative complications of resecting this tumor such as bleeding, wound dehiscence and even death. It is due to early diagnosis, treatment and good intraoperative management of lesion & hemodynamics. Case Report. A 21-year old male was referred from pulmonologist oncologist to our Thoracic Surgical Unit with complains of dyspnea and chest pain. Physical examination showed no lung sounds in (R) hemithorax and was dull to percussion, ictus cordis shifted 2 fingerbreadths towards left-side. Chest X-ray showed a large well-defined lesion in (R) hemithorax and chest CT-scan with contrast showed hypodense mass on (R) hemithorax adhering & compressing the lung, diaphragm, pericardium & chest wall, with estimation size of 60 x 20 x 12 cm, lesion displaced the heart. Patient was then treated with complete surgical excision and found a huge cystic tumor with a size of 60 x 20 x 12 cm adhering to all parts of (R) lung, diaphragm and pericardium. He underwent (R) pneumonectomy due to adhesion. Histologic examination was consistent with mature teratoma. Patient showed no complication after surgery and was discharged uneventfully from our hospital after 5 days. Discussion. Approximately 95% of benign teratomas arise in the anterior mediastinum. The tumor grows progressively, mostly asymptomatic, dyspnea and substernal chest pain are the most common symptoms if present. Productive Cough of hair or sebum is a pathognomonic sign. Chest radiograph typically reveals a well-circumscribed anterior mediastinal mass that often protrudes into one of the lung, they are usually large at the time of diagnosis. Complete surgical excision is a treatment of choice of mediastinal teratoma, which can be performed through median sternotomy or thoracotomy or thoracoscopy. Some patients require additional procedures (eg, lobectomy, pericardiectomy) for complete tumor resection. Conclusion. There is still limited data on mediastinal teratoma. Early referral & treatment show good prognosis. Benign Mediastinal Teratomas was tricky to be diagnosed, when it is diagnosed, it is usually very large in size. Complete Surgical Excision can be performed safely without any complications.

Utilization of texture features of volumetric ADC maps in differentiating between serous cystadenoma and intraductal papillary neoplasms.

The rising incidence of incidental detection of pancreatic cystic neoplasms has compelled radiologists to determine new diagnostic methods for the differentiation of various kinds of lesions. We aim to demonstrate the utility of texture features extracted from ADC maps in differentiating intraductal papillary mucinous neoplasms (IPMN) from serous cystadenomas (SCA). This retrospective study was performed on 136 patients (IPMN = 87, SCA = 49) split into testing and training datasets. A total of 851 radiomics features were extracted from volumetric contours drawn by an expert radiologist on ADC maps of the lesions. LASSO regression analysis was used to determine the most predictive set of features and a radiomics score was developed based on their respective coefficients. A hyper-optimized support vector machine was then utilized to classify the lesions based on their radiomics score. A total of four Wavelet features (LHL/GLCM/LCM2, HLL/GLCM/LCM2, /LLL/First Order/90percent, /LLL/GLCM/MCC) were selected from all of the features to be included in our classifier. The classifier was optimized by altering hyperparameters and the trained model was applied to the validation dataset. The model achieved a sensitivity of 92.8, specificity of 90%, and an AUC of 0.97 in the training data set, and a sensitivity of 83.3%, specificity of 66.7%, and AUC of 0.90 in the testing dataset. A support vector machine model trained and validated on volumetric texture features extracted from ADC maps showed the possible beneficence of these features in differentiating IPMNs from SCAs. These results are in line with previous regarding the role of ADC maps in classifying cystic lesions and offers new evidence regarding the role of texture features in differentiation of potentially neoplastic and benign lesions.

Diagnosis and treatment of patients with suspected mucinous cystic neoplasms of the liver: a retrospective cohort study

PurposeMucinous cystic neoplasms of the liver (MCN-L) are hepatic cysts with a low malignant potential. The recent European Association for the Study of the Liver (EASL) guidelines provide guidance on the imaging features and surgical management of MCN-L, yet are hampered by a lack of studies adhering to the revised World Health Organization (WHO) criteria. This study attempted to validate the new 2022 EASL-guidelines in a retrospective cohort study of patients who underwent surgery for suspected MCN-L.MethodsPatients undergoing surgery for suspected MCN-L in a single center between 2010 and 2020 were included. Imaging features were assessed according to the EASL guidelines and were compared to final pathological diagnoses, according to the WHO criteria.ResultsIn total, 35 patients were included. In three patients, there were no worrisome imaging features, yet final pathological diagnosis showed MCN-L. Contrarily, six patients with worrisome imaging features did not have MCN-L. Five patients were diagnosed with MCN-L on final pathology. The sensitivity of the EASL-guidelines for the diagnosis of MCN-L was 40% (95%CI: 5.3–85%) and the specificity was 80% (95% CI: 61–92%).ConclusionAlthough the new EASL-guidelines provide some guidance, they could not reliably distinguish MCN-L from other cysts in our series. Thus, preoperative diagnosis of MCN-L remains challenging and we should be careful in selecting surgical strategies based on these criteria.

Hemorrhagic Hepatic Cyst Mimicking a Cystic Neoplasm: Case Report

Background: Intracystic hemorrhage is an extremely rare complication of simple hepatic cysts. Clinical symptomatology is non-specific, and imaging frequently mimics a biliary cystadenoma or cystadenocarcinoma, which makes it challenging from a diagnostic point of view to an appropriate therapeutic approach. In this report, we present a case of a simple hemorrhagic hepatic cyst mimicking a cystic neoplasm. Case Report: 48-year-old men was referred to our hospital for periumbilical abdominal pain with asthenia and 11 kg weight loss. His physical examination and laboratory findings were unremarkable. Carcinoembryonic antigen concentration was three times higher than normal. Abdominal ultrasonography demonstrated an impure cystic mass measuring 120 x 96 x 108 mm on hepatic segments VI and VII. Abdominal CT showed a cystic mass at the liver possibly related to a cystadenocarcinoma. Abdominal MRI revealed a cystic mass with lobulated contours, located in segments VII, VIII and part of VI, measuring 11.8 x11.4 cm long axis, heterogeneous signal with intense fluid towards the top in T1 and T2 and intense fluid towards the decline in T2 and T1, with the appearance of a small inferior septum slightly enhanced after injection. These findings did not exclude the possibility of malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, endoscopic ultrasound showed a cystic lesion developing in the liver, with a thickened wall in places, mainly adjacent to an intracystic nodule of 25 mm, this nodule continued with the wall. Biopsy performed using a 22G ultrasound. Aspiration of liquid: string test negative. Pathological examination confirmed a hemorrhagic biliary cyst and there was no tumor tissue. We observed a significant improvement in symptoms and reduction in cyst size after needle aspiration and we decided to adopt a conservative approach. The patient was followed and one year later, the patient remained in good condition without any complaints. ................

Outcomes of Neoadjuvant Chemotherapy for Invasive Intraductal Papillary Mucinous Neoplasm Compared with de Novo Pancreatic Adenocarcinoma

BackgroundThe management of invasive intraductal papillary mucinous cystic neoplasm (I-IPMN) does not differ from de novo pancreatic ductal adenocarcinoma (PDAC); however, I-IPMNs are debated to have better prognosis. Despite being managed similarly to PDAC, no data are available on the response of I-IPMN to neoadjuvant chemotherapy.MethodsAll patients undergoing pancreatic resection for a pancreatic adenocarcinoma from 2011 to 2022 were included. The PDAC and I-IPMN cohorts were compared to evaluate response to neoadjuvant therapy (NAT) and overall survival (OS).ResultsThis study included 1052 PDAC patients and 105 I-IPMN patients. NAT was performed in 25% of I-IPMN patients and 65% of PDAC patients. I-IPMN showed a similar pattern of pathological response to NAT compared with PDAC (p = 0.231). Furthermore, positron emission tomography (PET) response (71% vs. 61%; p = 0.447), CA19.9 normalization (85% vs. 76%, p = 0.290), and radiological response (32% vs. 37%, p = 0.628) were comparable between I-IPMN and PDAC. A significantly higher OS and disease-free survival (DFS) of I-IPMN was denoted by Kaplan–Meier analysis, with a p-value of < 0.001 in both plots. In a multivariate analysis, I-IPMN histology was independently associated with lower risk of recurrence and death.ConclusionsI-IPMN patients have a longer OS and DFS after surgical treatment when compared with PDAC patients. The more favorable oncologic outcome of I-IPMNs does not seem to be related to early detection, as I-IPMN histological subclass is independently associated with a lower risk of disease recurrence. Moreover, neoadjuvant effect on I-IPMN was non-inferior to PDAC in terms of pathological, CA19.9, PET, and radiological response and thus can be considered in selected patients.

"The Remodelled Wen Cystic Trophoblastic Tumour Testis"

"The Remodelled Wen Cystic Trophoblastic Tumour Testis"

Sixteen cases of laparoscopic central pancreatectomy for benign or low-grade malignant tumours in the pancreatic neck and proximal body.

The purpose of this study is to examine and analyse the outcomes and patient experiences associated with laparoscopic central pancreatectomy. The perioperative data of 16 patients who underwent laparoscopic central pancreatectomy were retrospectively analysed at Ningbo Medical Center Lihuili Hospital (Xingning Branch and Eastern Branch) from September 2017 to July 2023. All surgical procedures were completed without the need for intraoperative conversion to open surgery. In two cases, intraoperative cholangiography was performed, while in four cases, intraoperative fluoroscopic laparoscopic assistance was utilized. The duration of the operations varied from 160 to 360 min, with an average of 281.75 min. The estimated volume of intraoperative bleeding ranged from 50 to 300 mL, with an average of 113.75 mL. The postoperative pathology results revealed that there were two cases of intraductal papillary mucinous neoplasm, six cases of serous cystic neoplasms, one case of mucinous cystic neoplasm, five cases of solid pseudopapillary neoplasms, and two cases of neuroendocrine tumours. The maximum diameter of the tumours ranged from 3.0 to 5.0 cm, with an average of 3.67 cm. There were no instances of postoperative common bile duct stenosis or biliary leakage. Among the cases, five did not exhibit pancreatic fistula, six experienced biochemical leakage, three had grade B pancreatic fistula, and two had grade C pancreatic fistula. Laparoscopic central pancreatectomy, as a method to preserve pancreatic function, entails specific surgical risks and a notable likelihood of postoperative pancreatic fistula, necessitating the expertise of seasoned surgeons for its execution.

MUCINOUS CYSTIC NEOPLASM OF LIVER - PEELING SIGN MITIGATES A DIAGNOSTIC CONUNDRUM

Background: Mucinous cystic neoplasms (MCN) are rare primary cystic neoplasms of the liver. It is commonly misdiagnosed for other cystic SOLs of liver. Clinical management of MCN is challenging due to scant literature on pre-operative and per-operative indices to distinguish MCN from other cystic SOLs of liver. Imprecise diagnosis leading to suboptimal surgical management results in recurrence and progression to malignancy. Methods: A retrospective analysis of cystic SOLs from July 2019 to July 2023 was analyzed in our centre. Data collection included demographics, clinical presentations, imaging characteristics, surgical techniques, intra-operative observations, complications, histopathology, post-operative follow-up, morbidity, and mortality. Results:Between July 2019 and July 2023, six patients were diagnosed and treated for MCN at our centre. Female patients were predominant (5 out of 6) with average age of 45.5yrs (Range 26-53). Abdominal discomfort was the commonest symptom (50%). All patients underwent abdominal ultrasounds and CT scans, while MRI was done in one patient. Two were misdiagnosed with non-neoplastic liver cysts and one had an ambiguous diagnosis. Four patients underwent liver resection and two had enucleation. All were MCN by HPE. In 3 patients, with ambiguous pre-op diagnosis, our recommended pre-operative and per-operative strategy including THE PEELING SIGN was helpful in diagnosing MCN. No recurrences were observed at 43 months of follow up. Conclusions:Liver MCNs are infrequent and often mistaken for other hepatic cystic conditions. By applying our pre-operative and per-operative indices, patients with MCN of liver can be diagnosed with precision and offered radical surgery.

Mitral valve leaflet blood cyst treated with minimally invasive approach: a case report and review of literature

IntroductionCardiac blood cyst is a very rare benign tumor of the heart in adults. Though it is very common in the first half year of life, it regresses with time and its occurrence is very rare in children older than six months and in adults. Until now less than 100 valvular blood cyst cases have been reported in adults.Case presentationWe present a case of a 66-year-old male who presented to us with exertional chest tightness, shortness of breath, and right leg weakness for two weeks. He was diagnosed with a cardiac mass two months ago in another hospital. The physical examination was unremarkable. Abdominal ultrasound showed a cyst in the liver and left kidney. Echocardiography showed a mass-occupying lesion of a cystic nature in the mitral valve with moderate mitral regurgitation. Based on echocardiography findings and computed tomography report, the preliminary diagnosis of mitral valve cystic tumor was made. The patient underwent minimally invasive resection of the cyst. The posterior mitral cusp was repaired and a mitral annuloplasty ring was placed. The postoperative recovery was uneventful. The histopathology report confirmed the diagnosis of a cardiac blood cyst. The patient was followed up for six months without any complications. This case is presented to enrich the medical literature on the cardiac blood cyst.ConclusionAlthough a cardiac blood cyst is a rare entity in adults, it still should be considered in the differential diagnosis of cardiac tumors. Because the natural history and hemodynamic effects are very diverse, large symptomatic cardiac blood cysts, especially in the left heart should be resected to avoid complications.

Assessment of the diagnostic significance of endoscopic ultrasonography in the differential diagnosis of formations of the hepatopancreatoduodenal zone

Purpose of the work. To study the structure of the hepatopancreaticoduodenal zone (HPD) masses according to the endosonographic picture and to estimate the diagnostic informativeness of endoscopic ultrasonography (EUS) in diagnostics of these masses in comparison with ultrasound examination of HPD (ultrasound of HPD) and computer tomography of abdominal cavity organs (CT of OBP) with contrasting. Materials and Methods. A retrospective analysis of medical records of 71 patients with GDZ masses who underwent inpatient treatment in the department of abdominal surgery and applied for diagnostic purposes to the endoscopic centre of Karaganda Multidisciplinary Hospital No.3 for EUS for the period from January 2021 to December 2022 was carried out. Results and discussion. Sensitivity of EUS in differential diagnostics of PG tumours, hepaticocholedochal dilatation, vascular invasion and metastasis to regional lymph nodes was 85%, 94,12%, 64,71% and 100% respectively, specificity - 95,93%, 100%, 80% and 92% respectively. Conclusion. Correct assessment of all manifestations of a tumour influences the choice of treatment tactics and consequently its immediate and long-term results. EUS is an effective method of differential diagnostics of pseudocysts and cystic tumours of PG, tumours of large duodenal papilla (LDP), as well as biliary tract neoplasms.

Comments on and illustrations of the WFUMB CEUS liver guidelines: Rare malignant neuroendocrine and predominant epithelioid liver lesions.

The diagnosis or rare, non-hematologic malignant lesions of the liver may be a challenge owing to the rarity of the disease, and is usually made by histological confirmation. Ultrasound with color Doppler and contrast-enhanced, if required, taking into account the clinical background of the patient, may help to focus the differential diagnosis. In this review, we describe the pathological and ultrasound features of rare malignant neuroendocrine and predominantly epithelioid liver lesions including primary neuroendocrine tumor of the liver, Invasive mucinous cystic neoplasm of the liver, and also hepatoblastoma.

Pancreatic Serous Cystadenoma: A Continuing Diagnostic Challenge.

Objective: To understand the natural history of serous cystadenoma. To understand the diagnostic accuracy of serous cystadenoma and identify possible factors that lead to the correct diagnosis. Summary Background data: Serous cystadenoma (SCA) is a benign cystic pancreatic neoplasm of the pancreas, accounting for approximately 15% of resected pancreatic cysts. Current recommendations are to proceed with surgical resection in symptomatic patients or when there is uncertainty regarding diagnosis. The latter continues to be a challenge since intentional resection of a serous cystadenoma account for only a minority of resected of cases. Methods: Retrospective single-institution review of patients who on final pathology had a diagnosis of pancreatic serous cystadenoma and of patients who had this diagnosis and were managed non-operatively. Demographic data, cyst characteristics, and growth rate were collected for analysis. Results: A total of 250 patients were analyzed. Median age was 62 (range 22 – 89), 65% were female, and 34% had symptoms. Tumor size ranged from 0.6 to 20, with a median of 3.4 cm. The morphological appearance was microcystic in 58%, macrocystic in 16%, mixed-type in 23%, and solid in 3%. Pancreatic duct dilation and pancreatic atrophy were found in 22% and 14%, respectively. The average growth rate was 1.8 mm/year regardless of tumor size. Of the 172 patients who underwent surgery, serous cystadenoma was the preoperative diagnosis in only 33%. A correct diagnosis was independently associated with large tumors and cyst fluid CEA analysis. Pancreatic duct dilation was independently associated with an in-growing cyst and presence of calcification. Conclusion: SCA is a slow-growing pancreatic cystic neoplasm that is mostly asymptomatic but can lead to pancreatic duct dilation and atrophy in some patients. A surprisingly small number of correct preoperative diagnoses confirms that this entity continues to be a diagnostic challenge. A more thorough preoperative workup that includes EUS should improve the rate of mis-diagnosis.

Abstract B072: SMAD4 loss allows progression from benign to malignant disease in intraductal papillary mucinous neoplasms

Abstract As increasing numbers of MRIs and other scans are ordered for unrelated diseases, more and more people are being diagnosed with cystic neoplasms of the pancreas. While many or most of these will likely remain benign, intraductal papillary mucinous neoplasms (IPMNs) have a risk of progression to cancer and IPMN is now recognized as another precursor to pancreatic ductal adenocarcinoma. We are investigating the mechanisms by which IPMNs progress from benign to malignant disease in order to identify markers of progression and targets to block that progression. We found that loss of SMAD4 in conjunction with Krasmutation leads to IPMN that quickly becomes invasive in a mouse model. Examining human IPMN tissues, we found that only one in 46 benign IPMN tumors lacked detectable SMAD4 protein. Among 19 cases of invasive IPMNs, the sites of active invasion were SMAD4 negative in 7 cases, nuclear negative/cytoplasm positive in 3 cases (suggesting no active canonical signaling), and a mix of positive and negative cells in 3 cases, implicating complete or partial loss of SMAD-mediated signaling in 68% of actively invading cells. In order to understand how SMAD signaling blocks progression to invasion, we are examining cell lines from a benign mouse model of IPMN. While these lines do not have endogenous TGF beta signaling, they are capable of responding to exogenous TGF beta, suggesting that TGF beta-related ligands may be supplied by the tumor microenvironment rather than the tumor cells themselves. We are currently determining how different TGF beta family members contribute to regulation of growth and invasion in these cells. In summary, loss of the tumor suppressor SMAD4 allows an otherwise benign disease to progress to invasive cancer. Citation Format: Anna L. Means, Hannah Yoo, Quoc-Huy Trinh, Roshini Thiagarajan, Jinghuan Zi, Frank L. Revetta, Marcus C. Tan, Kathleen E. DelGiorno, Mary K. Washington. SMAD4 loss allows progression from benign to malignant disease in intraductal papillary mucinous neoplasms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B072.

Abstract C049: Loss of RNF43 creates an OXPHOS dependency in early pancreatic neoplasia

Abstract Pancreatic ductal adenocarcinoma (PDAC) has a dismal 5-year survival of 12%. RNF43 is frequently mutated in pancreatic cystic neoplasms, including intraductal papillary mucinous neoplasms (IPMNs), which are precursor lesions of PDAC. RNF43 encodes for an E3 ubiquitin ligase and was initially identified as a negative Wnt regulator. To elucidate the role of RNF43-mutated neoplasms in an organ specific context, we have generated a genetically engineered mouse model which has pancreas specific loss of RNF43 (Hosein, Gastroenterology 2022). In this study we examine some of the metabolic dependencies created by Rnf43 loss on the background of mutant Kras, and how the Kras;Rnf43 model differs from the commonly used Kras;p53 model of PDAC. We have generated cell lines harboring mutant Kras and bi-allelic loss of Rnf43 from the resulting lesions in these mice (henceforth referred to as Kras;Rnf43 lines).Isogenic Kras;Rnf43 cell lines with re-expression of full-length Rnf43 (Kras;Rnf43-RNF43OE) were generated to confirm if observed phenotypes were Rnf43 dependent. Single-cell RNA sequencing (scRNA-seq) was performed for comparison between murine PDAC arising in Kras;Rnf43 versus Kras;p53 mice. We further compared metabolic parameters in Kras;Rnf43 and Kras;Rnf43-RNF43OE cells using the Seahorse platform. Mitochondrial ultrastructure by transmission electron microscopy (TEM) was analyzed in Kras;Rnf43 compared to Kras;p53 cells. To visualize endoplasmic reticulum (ER)-mitochondria contact sites (ERMCS), a split green fluorescent protein-based contact site sensor (SPLICS) was transfected and analyzed. Compared to Kras;p53 PDAC, Kras;Rnf43 tumors demonstrated upregulated mitochondrial transcripts and gene signatures of ER stress. Further, the ER stress response protein IRE1 was markedly elevated in Kras;Rnf43 cells versus Kras;p53 cells. The Kras;Rnf43 lines had enhanced mitochondrial oxidative phosphorylation (OXPHOS) activity and demonstrated evidence of enhanced mitochondrial quality control. ERMCS is a dynamic contact region between ER and mitochondria, which regulates biological processes including calcium homeostasis, ER stress and mitochondrial dynamics. The Kras;Rnf43 cells had significantly increased ERMCS compared to Kras;p53 cells. Finally, using IACS-010759, a small molecule inhibitor of OXPHOS, we demonstrate that Kras;Rnf43 cells had both increased in vitro sensitivity as well as in vivo susceptibility to tumor growth inhibition in orthotopic models, which translated into increased overall survival of mice. In conclusion, we provide evidence showing that bi-allelic loss of RNF43 is associated with increased ER stress and enhanced IRE1 dependent stress response. ER stress is mitigated via increased mitochondrial OXPHOS and ERMCS. Importantly, our results suggest that this creates a metabolic synthetic essentiality in the context of RNF43 loss, providing an avenue to suppress the progression of RNF43-mutated IPMNs, and potentially other solid cancers by targeting mitochondrial OXPHOS. Citation Format: Akiko Sagara, Brandon Chen, Nathaniel G. Yee, Megan J. Siemann, Costas A. Lyssiotis, Yatrik M. Shah, Sonja M. Woermann, Anirban Maitra. Loss of RNF43 creates an OXPHOS dependency in early pancreatic neoplasia [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C049.

Ovarian Hydatid Cyst: Case Report

Background: Hydatid disease is a zoonotic condition caused by the adult or the larval form of Echinococcus granulosus or less commonly Echinococcus multilocularis. The clinical presentation depends on the site of involvement. Many cases are not symptomatic and may be discovered accidentally. Hydatid cyst of the ovary is an extremely rare presentation that accounts for 0.2–1% of the diagnosed cases. It may be mistaken for ovarian cysts or cystic tumors of the ovary. The diagnosis is often based on the couple ultrasound-hydatid serology, but only the histopathological study can confirm the diagnosis of ovary hydatid cyst. Case report: A 40-years-old woman (G4P4), consulting for lower abdominal pain and frequent urination for the last 3 months. The clinical examination was normal besides a discrete pain in the supra-pubic region. Ultrasound of the abdomen showed evidence of cystic mass on the left ovary. A computerized tomography scan of the abdomen revealed the same lesion with no enhancement after contrast injection. In laparotomy we found a latero-uterine cystic lesion measuring approximately 6,5x3,5x4,7 cm there was evidence of a hydatid cyst of the left ovary. The treatment consisted on aspiration with injection of chlorhexidine. The patient underwent a hysterectomy with salpingo-oophorectomy with simple postoperative course. The diagnosis of hydatid cyst was confirmed through histopathological examination. Conclusion: The diagnosis of hydatic ovarian cyst is often based on the couple ultrasound-hydatid serology, but only the histopathological study can confirm the diagnosis The surgical treatment depends on the volume and location of the cysts. Hysterectomy remains the treatment of choice to avoid recurrences. Medical treatment is only necessary when the excision is incomplete or for multiple locations.