Pancreatic Cystic Tumors: A Single-Center Observational Study.

Background and Objectives: The aim of the study was to analyze the prevalence and characteristics of pancreatic cystic tumors (PCTs). Material and Methods: A retrospective analysis of the medical records of 124 patients, 102 (69%) women and 46 (31%) men, who had undergone surgery for pancreatic cystic tumors in 2014-2018. Among 148 pancreatic cysts, 24 (16%) were non-neoplasmatic and 124 (84%) were neoplasmatic. The neoplasmatic cysts (n = 124) were included in our analysis. There were five main types of PCTs: IPMN (intraductal papillary mucinous neoplasm) (n = 45), MCN (mucinous cystic neoplasm) (n = 30), SCN (serous cystic neoplasm) (n = 28), SPN (solid pseudopapillary neoplasm) (n = 8), and CPEN (cystic pancreatic endocrine neoplasm) (n = 8), as well as mixed-type tumors (n = 5). Results: A statistically significant dependency between PCT type and age was proven (p= 0.0001): IPMNs were observed in the older group of patients with an average age of 66.12 (40-79) years while SPNs were noted in the youngest group of patients with an average age of 36.22 (22-55) years. A statistically significant association between PCT type and gender (p = 0.0001) was found: IPMNs occurred among 24 (53.33%) men and 21 (46.6%) women. In the MCN and SPN groups, all patients were female (100%). Among the SCN group, the majority were women (27 (96.43%)), and there was only 1 (3.57%) man. A statistically significant dependency between PCT type and size was proven (p = 0.0007). The mean size of IPMNs was the smallest 2.95 (0.6-10 cm) and the mean size of MCNs was the largest 6.78 (1.5-19 cm). A statistically significant dependency between PCT type and tumor location was proven (p = 0.000238). The most frequent location of IPMN was the pancreatic head: 27 (60%). MCN was most frequently located in the pancreatic tail (18 (60%)). Most (10/28) SCNs were found in the pancreatic tail (10 (35.71%)). CPENs were most frequently located in the pancreatic tail (three (37.5%)) and pancreatic body and tail (three (37.5%)). SPNs were located commonly in the pancreatic head (five (62.5%)). The type of surgery depended on the tumor location. The most frequent surgery for IPMNs was pancreatoduodenectomy (44.4%), while for MCNs and SCNs, it was distal pancreatectomy (81%). The postoperative morbidity and mortality were 34.68% and 1.61%, respectively. Postoperative pancreatic fistula (POPF) was the most frequent (29%) complication. Conclusions: IPMN was the most frequent resected PCT in our material. A statistically significant association between the type of cyst and location within the pancreas, size, local lymph node involvement, and patient's age and sex was proved. POPF was the most frequent postoperative complication. In patients with PCTs, due to substantial postoperative morbidity, adequate patient selection, considering both the surgical risk as well as the long-term risk of malignant transformation, is very important during qualification for surgery.

Sex-dependent expression of prostatic markers and hormone receptors in cystic tumor of the atrioventricular node: A histopathological study of three cases.

We pathologically investigated three autopsy cases of cystic tumor of the atrioventricular node (CTAVN) with sudden death. Case 1 was a 36-year-old woman without any clinical history. Case 2 was a 76-year-old man with an implanted pacemaker for complete atrioventricular block. Case 3 was a 45-year-old man with a history of first-degree AV block and sinus bradycardia. Microscopically, all three cases showed the bilayered structure of tumor glands and corpora amylacea in the glandular lumens. Immunohistochemically, the inner cells of the tumor glands were positive for cytokeratin CAM5.2, CEA, EMA, olfactomedin-4 and alpha-methylacyl-coenzyme A racemase; the outer cells were positive for p63 and cytokeratin high molecular weight. In Case 1, androgen receptor and estrogen receptor were negative; progesterone receptor was focally positive in both the inner and outer cells. In Case 2, androgen receptor showed intermediate positivity in the inner cells; estrogen receptor and progesterone receptor were positive in the outer cells. Positive expression of both prostate-specific antigen and prostate-specific acid phosphate were found in the inner cells of both male cases. Because CTAVN cells exhibit different degrees of the prostatic phenotype depending on the patient's sex, we believe that CTAVN may originate from urogenital sinus tissue in some cases.

Primary retroperitoneal mucinous cystadenocarcinoma in pregnancy - case report.

INTRODUCTION: Primary retroperitoneal mucinous cystadenoma (PRMC) and its malignant variant - cystadenocarcinoma are extremely rare tumors known only from case studies and reviews. PRMC is a cystic tumor of the retroperitoneum, which remains asymptomatic for a long time and can reach significant proportions. It occurs mainly in women. CASE REPORT: We present the case of a 38-year-old healthy woman with diagnosed resistance in the right mesogastrium during a c-section. The delivery was terminated without a surgical intervention. The above mentioned resistance was examined further by ultrasound, computed tomography and magnetic resonance imaging. All imaging examinations showed a solid - cystic bilocular expansion, which looked like a mesenteric cyst in the right paracolic area. The patient was asymptomatic at all times, with only a palpable resistance of the abdominal wall. In November 2020, the patient underwent an elective surgery - extirpation of the cystic tumor and prophylactic appendectomy. The operation was performed classically, via midline laparotomy without perioperative perforation of the cystic tumor and without complications in the postoperative period. The histopathological examination showed a malignant variant of PRMC. So far, the patient remains free of any problems and is followed at the department of oncology. CONCLUSION: The goal of treatment is to achieve complete surgical removal of the tumor without its perioperative perforation. Due to the rare occurrence of the disease, there are no guidelines for the diagnosis and treatment of PRMC. Precisely because PRMC is a rare tumor, it should be part of the differential diagnosis of cystic tumors of the retroperitoneum, especially when young women are concerned.

[Combination of intraductal papillary mucinous neoplasm with other cystic pancreatic tumors]. / Sochetanie vnutriprotokovoi papillyarnoi mutsinoznoi opukholi s drugimi kistoznymi opukholyami podzheludochnoi zhelezy.

Cystic tumors of the pancreas are uncommon entities. Synchronic occurrence of intraductal papillary mucinous neoplasm (IPMN) and other pancreatic tumors is extremely rare. Two patients with this diagnosis are reported in the manuscript. Cystic tumors of the pancreas can rarely occur in various combinations while malignancy potential of each neoplasm may be different. Surgery depends on localization and type of each tumor and must be determined individually.

LINAC-based stereotactic radiosurgery versus hypofractionated stereotactic radiotherapy delivered in 3 or 5 fractions for vestibular schwannomas: comparative assessment from a single institution.

PURPOSE: The optimal treatment strategy for vestibular schwannoma (VS) is not known, and different radiation techniques and fractionation regimens are currently being used. This report aimed to assess outcomes after LINAC-based radiosurgery (SRS) and hypofractionated radiotherapy (hypo-FSRT) and identify possible differences in outcomes between hypo-FSRT delivered in 3 or 5 fractions. METHODS: From 2005 to 2017, 136 patients underwent treatment with radiotherapy for VS. Thirty-seven patients received SRS (12 Gy), and 99 received hypo-FSRT. Hypo-FSRT was delivered in 3 fractions (total 18-21 Gy, n = 39) and 5 fractions (total 25 Gy, n = 60). RESULTS: The median follow-up was 57 months. Eight patients had progression requiring surgery, corresponding to an overall local control rate of 93.4%, with no significant difference between the fractionation schedules. A correlation with borderline significance (p = 0.052) was detected between cystic tumors and local failure. A tendency toward a higher incidence of local failure was observed after 2015 when SRS treatment increased and included slightly larger tumors. Hearing preservation was observed in 35% of patients and 36% of patients experienced acute side effects, but persistent facial or trigeminal nerve toxicity was rare. CONCLUSION: SRS and hypo-FSRT with 3 or 5 fractions provided a high rate of local control with no significant differences between treatment schedules. SRS is a well-documented radiation technique for VS and is the recommendation for small- to medium-sized tumors. This report demonstrates excellent long-term outcomes after hypo-FSRT; this regimen can be delivered safely and is an alternative for selected patients.

Epidermoid cyst in an intrapancreatic accessory spleen in the pancreas head: a case report.

BACKGROUND: An epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS) in the pancreas head is an extremely rare condition. The natural course of this condition is not well known, and it is difficult to diagnose before surgery due to the lack of specific imaging findings. CASE PRESENTATION: A tumor was found in the head of the pancreas in a 68-year-old man with abdominal distension and discomfort. Magnetic resonance imaging (MRI) suggested a malignant tumor, such as a colloid cancer. The tumor was removed surgically, with pathologic examination showing that it was an ECIPAS. CONCLUSION: ECIPAS cannot be easily distinguished from other pancreatic cystic tumors, making it necessary to include ECIPAS in the differential diagnosis of these tumors. Unnecessary surgical resection may be avoided by more accurate preoperative diagnosis based on clinical and imaging characteristics.

[Intraductal papillary mucinous neoplasm of pancreas]. / Vnutriprotokovaia papilliarnaia mutsinoznaia opukhol' podzheludochnoi zhelezy.

Intraductal papillary mucinous neoplasm (IPMN) is the most common cystic pancreatic tumor. There are 3 ductal types of this tumor depending on localization. Several histological subtypes determine clinical course and prognosis. The problems of diagnosis, surgical treatment and follow-up are reviewed in several guidelines. Literature review devoted to pancreatic IPMN is presented in the article, the latest guidelines are compared.

Magnetic resonance imaging as an adjunct diagnostic tool in computed tomography defined Bosniak IIF-III renal cysts: a multicenter study.

INTRODUCTION: CT imaging is the standard examination for renal cystic lesions and defines the Bosniak category, which dictates further management. Given that Bosniak II/IIF/III renal cystic lesions can potentially harbor renal cell carcinoma (RCC), additional diagnostic modalities may be required in management decision making. AIM: To determine the value of additional magnetic resonance imaging in CT-defined Bosniak IIF-III renal cystic lesions. MATERIALS AND METHODS: This a multicenter retrospective study of 46 consecutive patients, diagnosed with cystic renal lesions between 2009 and 2016. The inclusion criteria were: (1) cystic renal lesion classified as Bosniak IIF-III on CT, (2) a subsequent MRI examination, and (3) documented outcome via surgery for cystic renal mass or follow-up. RESULTS: 46 patients (35 males, 11 females) were included. The mean size of the cystic lesion was 3.92 cm (0.7-10 cm). According to the CT findings, Bosniak IIF and III were found in 12 (26.1%) and 34 (73.9%) cases. Reclassification of Bosniak category was done after MRI examination in 31 cases (67.4%). An upgrade rate of 58.7% (27 cases) to a higher category was made, while the downgrade rate to a lower category was achieved in 4 cases (8.7%). As a result, significant therapeutic management change was made in 12/31 patients (38.7%), of whom 8 underwent subsequent surgery. CONCLUSION: MRI study may reduce the use of Bosniak IIF category (in comparison with CT), which has a direct impact on therapeutic management (surgery vs. surveillance) in a significant proportion of patients.

Contrast enhanced ultrasound features of hepatic cystadenoma and hepatic cystadenocarcinoma.

OBJECTIVE: Hepatic (biliary) cystic tumor (HBCT) is a rare focal cystic liver lesion, which has been rarely described in the literature. In our current multicenter, retrospective study, we aimed to analyze contrast enhanced ultrasound (CEUS) features and its diagnostic performance in histologically proved HBCT. MATERIAL AND METHODS: Twenty-three patients with single HBCT were retrospectively analyzed. Histologically, 17 (73.9%) were benign hepatic (biliary) cystadenoma (HBCA), 6 (26.1%) were hepatic (biliary) cystadenocarcinoma (HBCAC). All CEUS examinations were assessed by two independent radiologists in consensus. Criteria of CEUS imaging evaluation included the contrast enhancement pattern of lesion (hypoenhancing, hyperenhancing, isoenhancing in comparison to the surrounding liver parenchyma) during the arterial, portal venous and late phases. RESULTS: After injection of ultrasound contrast agents, most of the HBCTs (78.3%, 18/23) had typical honeycomb enhancement pattern of the cystic wall, septa or mural nodules. Comparing between HBCA and HBCAC, hyperenhancement of the honeycomb septa during the arterial phase was more common in HBCA (p = .047). However, hypoenhancement during the portal venous and late phases was the characteristic of HBCAC (p = .041). CONCLUSIONS: The EFSUMB algorithm for CEUS for characterization of solid focal liver lesions is also applicable to HBCT. CEUS evaluation can avoid further diagnostic investigations or invasive biopsy procedure.

Multicystic biliary hamartoma with extremely elevated CA19-9: a case report.

Multicystic biliary hamartoma (MCBH) is a rare cystic disease of the liver. We herein report a case of MCBH associated with extremely elevated levels of serum carbohydrate antigen (CA) 19-9. A 53-year-old man was referred to our hospital because of extremely elevated CA19-9 levels (more than 12,000 U/mL). Enhanced abdominal computed tomography and magnetic resonance imaging (MRI) revealed a multicystic tumor with a calcified wall in the left lobe of the liver, although no apparent intracystic nodule was detected. Because of the possibility of a malignant tumor, such as intraductal papillary neoplasm of the bile duct or cystadenocarcinoma, the patient underwent left hepatectomy. Based on the postoperative pathological findings, the lesion was diagnosed as MCBH. The serum CA19-9 level drastically decreased after surgery. We encountered a rare case of MCBH with extremely elevated CA19-9 levels.

Nature and management of pancreatic mucinous cystic neoplasm (MCN): A systematic review of the literature.

BACKGROUND: The current management of pancreatic mucinous cystic neoplasms (MCN) is defined by the consensus European, International Association of Pancreatology and American College of Gastroenterology guidelines. However, the criterion for surgical resection remains uncertain and differs between these guidelines. Therefore through this systematic review of the existing literature we aimed to better define the natural history and prognosis of these lesions, in order to clarify recommendations for future management. METHODS: A systematic literature search was performed (PubMed, EMBASE, Cochrane Library) for studies published in the English language between 1970 and 2015. RESULTS: MCNs occur almost exclusively in women (female:male 20:1) and are mainly located in the pancreatic body or tail (93-95%). They are usually found incidentally at the age of 40-60 years. Cross-sectional imaging and endoscopic ultrasound are the most frequently used diagnostic tools, but often it is impossible to differentiate MCNs from branch duct intraductal papillary mucinous neoplasms (BD-IPMN) or oligocystic serous adenomas pre-operatively. In resected MCNs, 0-34% are malignant, but in those less than 4 cm only 0.03% were associated with invasive adenocarcinoma. No surgically resected benign MCNs were associated with a synchronous lesion or recurrence; therefore further follow-up is not required after resection. Five-year survival after surgical resection of a malignant MCN is approximately 60%. CONCLUSIONS: Compared to other pancreatic tumors, MCNs have a low aggressive behavior, with exceptionally low rates of malignant transformation when less than 4 cm in size, are asymptomatic and lack worrisome features on pre-operative imaging. This differs significantly from the natural history of small BD-IPMNs, supporting the need to differentiate mucinous cyst subtypes pre-operatively, where possible. The findings support the recommendations from the recent European Consensus Guidelines, for the more conservative management of MCNs.

Mucinous cystic tumor with CK20 and CDX2 expression of the thymus: Is this a benign counterpart of adenocarcinoma of the thymus, enteric type?

Primary thymic adenocarcinoma is extremely rare. Moreover, thymic pure epithelial benign neoplasms are extremely rare. We encountered a cystic tumor almost purely composed of goblet cell-like mucus-producing cells of the thymus. A mass lesion of the mediastinum was detected in a 54-year-old man. The gross specimen presented a unilocular cystic lesion containing abundant mucin, measuring 8 × 5.5 × 4.5 cm. Microscopic examination revealed a cystic tumor consisting of bland mucus-producing cells resembling goblet cells and forming tiny daughter cysts within the dense fibrous capsule. No destructive growth or infiltration into surrounding thymic tissue was observed. Papillary growth was found in a small focus. Immunohistochemically, tumor cells were positive for cytokeratin 20 and caudal type homobox 2, which are representative markers of enteric differentiation. The patient has been well without any recurrence for approximately ten years after the operation. Thus, the tumor should be regarded as a mucinous cystic tumor in the thymus. Very recently, thymic adenocarcinoma with enteric differentiation was proposed as a novel subtype of thymic carcinoma. This case could be regarded as a benign counterpart of adenocarcinoma of the thymus, enteric type. A further follow-up study is required to confirm the exact biological behavior of this tumor.

Analysis of clinical characteristics and treatment of pancreatic cystic tumors.

OBJECTIVE: To summarize experience in the diagnosis and treatment of pancreatic cystic neoplasms. METHODS: This is a retrospective study of 207 patients who were diagnosed with pancreatic cystic tumors at Peking Union Medical College Hospital between Jan 2009 and Mar 2014. Clinical data, such as clinical manifestations, radiological and pathological images and surgical recordings, were collected. RESULTS: Of the 207 included patients, females accounted for 76.81%, and the mean patient age was 52.04 years. Malignancy was more common in older patients who presented with marasmus and jaundice. Other risk factors included solid components in the tumor, a large tumor size, and elevated levels of tumor markers. Surgical treatment was required when a malignant tumor was suspected. The operation approach was selected based on the location, size and characteristics of the tumor. The position of the tumor relative to the pancreatic duct also played a significant role. CONCLUSIONS: No specific symptoms were observed for the patients with pancreatic cystic tumors. Imaging played an important role in making a differential diagnosis. Furthermore, surgical treatment should be proposed for patients with significant symptoms and potentially malignant tumors. The tumor resection rate is high, suggestive of good prognosis.

A massive multicystic parapharyngeal tumor: A case report.

Cervical sympathetic chain schwannomas are uncommon benign tumors that usually develop in the retrostyloid compartment of the parapharyngeal space. Differentiating cervical sympathetic chain schwannomas from other lesions of the retrostyloid parapharyngeal space can be very difficult. We present a case of a major ingrowth of a cervical lesion, covering the larynx and obstructing the airway beyond the midline. The imaging revealed an extensive parapharyngeal lesion with significant cystic degeneration, which complicated the radiological diagnosis. Severe cystic degeneration of a cervical schwannoma is associated with fast expansion, and near-fully cystic schwannomas have been described in the literature.

A unique case of a typical pancreatic ductal adenocarcinoma that initially presented with a cystic component but underwent morphological changes.

A 66-year-old man was initially suspected of having a microcystic serous cystic neoplasm based on magnetic resonance imaging findings of a multifocal mass measuring 46 mm in the pancreatic head, with a cystic component showing a high signal on T2-weighted images. The tumor marker levels were within normal limits. However, contrast-enhanced computed tomography revealed thick cyst walls with delayed staining, which was atypical for serous cystic neoplasms; therefore, the patient was followed up closely. Twenty-two months later, the delayed contrast area was enlarged, carbohydrate antigen 19-9 levels were elevated, and 18 F-fluorodeoxyglucose-positron emission tomography revealed increased accumulation, indicating a potentially malignant lesion. Pancreatoduodenectomy was performed and histopathological examination confirmed the diagnosis of normal-type pancreatic carcinoma with predominantly poorly differentiated cells. Based on the pathological findings and a literature review, it is highly likely that this case represents pancreatic ductal adenocarcinoma with a cystic structure from the beginning. While distinguishing pancreatic ductal adenocarcinoma from other pancreatic cystic tumors, such as serous cystic neoplasms, is critical owing to differing treatments and prognoses, caution is warranted as they may exhibit similar imaging features, as observed in our patient.

Extremely slow-growing cerebellar ganglioglioma in an elderly patient.

Background: Gangliogliomas account for 0.4% of primary brain tumors. They mainly occur in the supratentorial compartment and typically affect only children and young adults. We present an especially rare case of cerebellar ganglioglioma in an elderly patient. Case Description: A 76-year-old Japanese woman presented with headache and nausea from 1 month previously. She had been diagnosed with a cerebellar tumor in her childhood, but the lesion was asymptomatic at that time, and there was no evidence of an increase in size, so it had been monitored without surgery. At the time of presentation, she had not been examined for approximately ten years. On admission, magnetic resonance imaging indicated a T2 hypertense cyst in the cerebellar vermis. Post-contrast T1 imaging showed an enhanced mural nodule in the cyst. Cerebral angiography showed that none of the vertebral arteries were significant feeders. The tumor was removed through posterior fossa craniotomy. The histopathological diagnosis was ganglioglioma. The patient's headache and nausea improved after surgery. Conclusion: Our patient presented a very rare case of extremely slow-growing elderly ganglioglioma in the cerebellum. In patients with gangliogliomas, long-term follow-up is important because the disease may become symptomatic at an older age.

A contrast-enhanced computed tomography-based radiomics nomogram for preoperative differentiation between benign and malignant cystic renal lesions.

Background: There is lack of discrimination as to traditional imaging diagnostic methods of cystic renal lesions (CRLs). This study aimed to evaluate the value of machine learning models based on clinical data and contrast-enhanced computed tomography (CECT) radiomics features in the differential diagnosis of benign and malignant CRL. Methods: There were 192 patients with CRL (Bosniak class ≥ II) enrolled through histopathological examination, including 144 benign cystic renal lesions (BCRLs) and 48 malignant cystic renal lesions (MCRLs). Radiomics features were extracted from CECT images taken during the medullary phase. Using the light gradient boosting machine (LightGBM) algorithm, the clinical, radiomics and combined models were constructed. A comprehensive nomogram was developed by integrating the radiomics score (Rad-score) with independent clinical factors. Receiver operating characteristic (ROC) curves were plotted. The corresponding area under the curve (AUC) value was worked out to quantify the discrimination performance of the three models in training and validation cohorts. Calibration curves were worked out to assess the accuracy of the probability values predicted by the models. Decision curve analysis (DCA) was worked out to assess the performance of models at different thresholds. Results: Maximum diameter and Bosniak class were independent risk factors of patients with MCRL in the clinical model. Twenty-one radiomics features were extracted to work out a Rad-score. The performance of the clinical model in the training cohort was AUC =0.948, 95% confidence interval (CI): 0.917-0.980, and the performance in the validation cohort was AUC =0.936, 95% CI: 0.859-1.000 (P<0.05). The performance of the radiomics model in the training cohort was AUC =0.990, 95% CI: 0.979-1.000, and the performance in the validation cohort was AUC =0.959, 95% CI: 0.903-1.000 (P<0.05). Compared with the above models, the combined radiomics nomogram had an AUC of 0.989 (95% CI: 0.977-1.000) in the training cohort and an AUC of 0.962 (95% CI: 0.905-1.000) in the validation cohort (P<0.05), showing the best diagnostic efficacy. Conclusions: The radiomics nomogram integrating clinical independent risk factors and radiomics signature improved the diagnostic accuracy in differentiating between BCRL and MCRL, which can provide a reference for clinical decision-making and help clinicians develop individualized treatment strategies for patients.

Variations in subtle cystic tumors of the atrioventricular node: Five autopsy cases.

Cystic tumor of the atrioventricular node (CTAVN) is the most common primary cardiac tumor cause of sudden death but is rarely found during forensic autopsy. We present five autopsy cases of sudden death from undiagnosed CTAVN. The tumors varied in their histological appearance, which may be related to their variation in clinical presentation. Some of the cases had been diagnosed with epilepsy before death; it seems that syncopal attacks caused by CTAVN may be misdiagnosed as epilepsy. When performing forensic autopsy, CTAVN should be considered in the differential diagnosis of sudden death. Careful examination of the cardiac conduction system is important in every sudden death case regardless of age.

Fetal cystic and solid tumor of the atrioventricular node: Autopsy diagnosis at 12 weeks of gestational age.

Primary cardiac tumors are uncommon clinical entities with an incidence of 0.0017% to 0.03% of all autopsies. Cystic tumor of the atrioventricular node (CTAVN) comprises of 2.7% of cardiac tumors causing sudden death associated with complete heart block. CTAVN is a congenital benign cystic and solid mass located in the triangle of Koch in atrioventricular nodal region of the heart. It has been described from infancy to adulthood, most often as an incidental finding at autopsy, but has been not yet described in fetuses. We report a case of late spontaneous abortion detected during the first ultrasound follow-up consultation at 12w+1d of gestation in a healthy 23-year-old pregnant woman, gravida 2 para 0 and one previous termination of pregnancy. Pathological study of abortion product was request. No abnormalities were detected on gross examination, but microscopically, characteristics features of cardiac cystic and solid tumor of the atrioventricular node were identified. We present the first case described in literature of a congenital benign CTAVN in a non-macerate, normal, female fetus with an appropriate growth and development for 12w+1d of gestational age. There are many reasons for performing a fetal post-mortem autopsy foremost of which is identifying an accurate cause of death.

Bilateral renal hydatid disease associated with complex urolithiasis: A case report.

INTRODUCTION AND IMPORTANCE: The association of bilateral renal hydatid cysts and complex urolithiasis is unprecedented. We herein report the case of a patient presenting with both diseases. CASE PRESENTATION: A 56-year-old female patient with a history of chronic kidney disease presented with right flank pain. Imaging revealed bilateral kidney cystic lesions associated with right spontaneous large ureteric streinstrasse and multiple calyceal stones. The right sided mass was exophytic and measured 56 mm and the left sided lesion measured 35 mm. Semi rigid right ureteroscopy was performed along with a right partial nephrectomy and a right pyelotomy which allowed for renal and ureteral stone extraction. Histopathology report concluded to a hydatid cyst. The decision was to monitor the left-sided lesion. CLINICAL DISCUSSION: The association of bilateral renal hydatidosis and right urolithiasis is unprecedented in literature. The lesion presented a differential diagnosis problem with a cystic malignancy. Thus, the decision was to perform a right partial nephrectomy. The combination of ureteroscopy and a single right flank incision was sufficient to treat the renal lesion as well as to obtain stone free status. Once the histopathological report concluded to a hydatid cyst, the decision was to monitor the left sided lesion. A more aggressive approach could be proposed however it would have been detrimental to the patient's renal function. CONCLUSION: When presented with an association of bilateral renal masses and urolithiasis, a methodical step-by-step approach is necessary in order to treat both diseases while minimizing patient morbidity.