Comparative analysis of retro vs. transperitoneal laparoscopic pyelolithotomy for large renal stones.

The objective of this study is to compare the outcomes and complications of retroperitoneal and transperitoneal laparoscopic pyelolithotomy (RLP and TLP, respectively) in the treatment of large kidney stones. In this retrospective cohort effort, data of all patients who underwent laparoscopic pyelolithotomy for renal pelvic stone (N = 273) in three referral urology hospitals were retrieved. Operation duration, length of hospital stay, postoperative stone-free rate, hemoglobin (Hb) and creatinine (Cr) changes and complications were compared between the two groups before and after propensity score matching. A total of 199 TLP and 74 RLP cases were examined. Stone size was significantly higher in the TLP vs. RLP group (29.8 ± 10.9 vs. 26.5 ± 8.8 mm; P = .022). Length of operation and hospital stay were comparable (P = .672 and P = .396, respectively). Rate of conversion to open surgery, postoperative blood transfusion rate, postoperative urinary leakage, postoperative stone-free rate, Hb drop and Cr change were similar between the two groups (P = .348, 0.190, 0.828, 0.411, 0.780 and 0.134, respectively). Postoperative fever was significantly more prevalent in TLP compared to RLP (21.6% vs. 0.0%, respectively; P < .001). Propensity score matched analyses showed similar results in all aspects; particularly demonstrating higher postoperative fever in TLP compared to RLP (18.9% vs. 0.0%, respectively; P < .001). RLP can be considered as an alternative to TLP; especially owing to a lower chance of postoperative fever.

A Rare Case of a Gigantic Retroperitoneal Schwannoma.

Introduction: Schwannomas (Schs) are benign tumor masses that rarely occur intra-abdominally and rarely reach larger diameters. When present, they occur as rare solitary nerve sheath tumors of peri-neural Schwann cells. Schwannoma mostly affects the nerves of the extremities, trunk, or the head and neck region. They are more common in female patients, mostly among patients between the third and fifth decade. They occur spontaneously but could also be found in association with a group of genetic autosomal dominant disorders called type 2. When present intra-abdominally, schwannomas grow slowly without significant clinical signs and symptoms. Clinical importance is presented in cases of occupying intra-abdominal space and impingement of surrounding structures, which causes intermittent pain. Only 0.5-5% of all retroperitoneal tumors are schwannomas and their malignant transformation is very rare. Case report: The authors present a case of a large intra-abdominal schwannoma in a 70-year-old female patient. She underwent CT scanning due to refractory left-sided subcostal pain, which revealed a large tumor mass in the left-sided hemiabdomen. Preoperative cytologic biopsy confirmed Sch. The patient underwent an MRI scan upon admission to our department, which revealed the origin of the tumor at the left-sided L3 level and intra-abdominal tumor spreading with the largest diameter of 25 cm. The patient underwent multidisciplinary surgical excision, confirmed by MRI scan in a period of five months postoperatively. Conclusions: Its rare presentation leads to the necessity to adequately evaluate such patients, especially to avoid any hidden diagnosis which might lead to further complications. The goal of a multidisciplinary approach should be emphasized as maintaining a good postsurgical condition without neurological deficits.

Sentinel node mapping decreases the risk of failed detection of isolated positive para-aortic lymph node in endometrial cancer.

BACKGROUND: Isolated positive para-aortic lymph node metastasis in endometrial cancer is an uncommon event, ranging from 1% to 3%. OBJECTIVE: Our aim was to evaluate the impact of sentinel lymph node (SLN) mapping on the risk of isolated positive para-aortic lymph node metastasis. METHODS: We retrospectively evaluated a series of 426 patients who underwent SLN mapping with at least one SLN detected from January 2013 to December 2021 (SLN group) compared with a historical series of 209 cases who underwent a systematic pelvic and para-aortic lymphadenectomy between June 2007 and April 2015 (LND group). Isolated para-aortic lymph node metastasis recurrences were included in the SLN group analysis. RESULTS: In the SLN group, 168 cases (39.4%) had backup systematic lymphadenectomy, and 56 (13.1%) had positive lymph nodes compared with 34 (16.3%) in LND group (p=0.18). The SLN group had higher rates of minimally invasive surgeries (p<0.001) and presence of lymphovascular space invasion (p<0.001). Moreover, SLN group had fewer other uterine risk factors, such as high-grade tumors (p<0.001), and deep myometrial invasion (p<0.001). We found that SLN mapped outside the pelvis at pre-sacral, common iliac areas, and para-aortic regions in 2.8% (n=12), 11.5% (n=49), and 1.6% (n=7) of cases, respectively. Overall, 52 (12.2%) patients had positive SLNs, and 3 (5.7%) positive SLNs were found outside the pelvis-one in the pre-sacral region, one in the common iliac area, and one in the para-aortic region. An isolated para-aortic lymph node was found in only 2 (0.5%) cases in the SLN group compared with 7 (3.3%) cases in the LND group (p=0.004). CONCLUSIONS: SLN protocol accurately predicts lymph node status and may decrease the risk of failed identification of isolated para-aortic lymph node metastasis compared with systematic lymphadenectomy.

Understanding the Anatomy of Retroperitoneal Interfascial Space: Implications for Regional Anesthesia.

BACKGROUND: Fascial plane block techniques have evolved considerably in recent years. Unlike the conventional peripheral nerve block methods, the fascial plane block's effect can be predicted based on fascial anatomy and does not require a clear vision of the target nerves. The anatomy of the retroperitoneal interfascial space is complex, since it comprises multiple compartments, including the transversalis fascia (TF), the retroperitoneal fasciae (RF), and the peritoneum. For this reason, an in-depth, accurate understanding of the retroperitoneal interfascial space's anatomical characteristics is necessary for perceiving the related regional blocks and mechanisms that lie underlie the dissemination of local anesthetics (LAs) outside or within the various retroperitoneal compartments. OBJECTIVES: This review aims to summarize the retroperitoneum's anatomical characteristics and elucidate the various communications among different interfascial spaces as well as their clinical significance in regional blocks, including but not limited to the anterior quadratus lumborum block (QLB), the fascia iliaca compartment block (FICB), the transversalis fascia plane block (TFPB), and the preperitoneal compartment block (PCB). STUDY DESIGN: This is a narrative review of pertinent studies on the use of retroperitoneal spaces in regional anesthesia (RA). METHODS: We conducted searches in multiple databases, including PubMed, MEDLINE, and Embase, using "retroperitoneal space," "transversalis fascia," "renal fascia," "quadratus lumborum block," "nerve block," and "liquid diffusion" as some of the keywords. RESULTS: The anatomy of the retroperitoneal interfascial space has a significant influence on the injectate spread in numerous RA blocking techniques, particularly the QLB, FICB, and TFPB approaches. Furthermore, the TF is closely associated with the QLB, and the extension between the TF and iliac fascia offers a potential pathway for LAs. LIMITATIONS: The generalizability of our findings is limited by the insufficient number of randomized controlled trials (RCTs). CONCLUSIONS: Familiarity with the anatomy of the retroperitoneal fascial space could enhance our understanding of peripheral nerve blocks. By examining the circulation in the fascial space, we may gain a more comprehensive understanding of the direction and degree of injectate diffusion during RA as well as the block's plane and scope, possibly resulting in effective analgesia and fewer harmful clinical consequences.

Preoperative Contrast-Enhanced CT-Based Deep Learning Radiomics Model for Distinguishing Retroperitoneal Lipomas and Well­Differentiated Liposarcomas.

RATIONALE AND OBJECTIVES: To assess the efficacy of a preoperative contrast-enhanced CT (CECT)-based deep learning radiomics nomogram (DLRN) for predicting murine double minute 2 (MDM2) gene amplification as a means of distinguishing between retroperitoneal well-differentiated liposarcomas (WDLPS) and lipomas. METHODS: This retrospective multi-center study included 167 patients (training/external test cohort, 104/63) with MDM2-positive WDLPS or MDM2-negative lipomas. Clinical data and CECT features were independently measured and analyzed by two radiologists. A clinico-radiological model, radiomics signature (RS), deep learning and radiomics signature (DLRS), and a DLRN incorporating radiomics and deep learning features were developed to differentiate between WDLPS and lipoma. The model utility was evaluated based on the area under the receiver operating characteristic curve (AUC), accuracy, calibration curve, and decision curve analysis (DCA). RESULTS: The DLRN showed good performance for distinguishing retroperitoneal lipomas and WDLPS in the training (AUC, 0.981; accuracy, 0.933) and external validation group (AUC, 0.861; accuracy, 0.810). The DeLong test revealed the DLRN was noticeably better than clinico-radiological and RS models (training: 0.981 vs. 0.890 vs. 0.751; validation: 0.861 vs. 0.724 vs. 0.700; both P < 0.05); however, no discernible difference in performance was seen between the DLRN and DLRS (training: 0.981 vs. 0.969; validation: 0.861 vs. 0.837; both P > 0.05). The calibration curve analysis and DCA demonstrated that the nomogram exhibited good calibration and offered substantial clinical advantages. CONCLUSION: The DLRN exhibited strong predictive capability in predicting WDLPS and retroperitoneal lipomas preoperatively, making it a promising imaging biomarker that can facilitate personalized management and precision medicine.

Retroperitoneal bronchogenic cyst: A case report and review of literature.

BACKGROUND: Bronchogenic cysts are rare developmental anomalies that belong to the category of congenital enterogenous cysts. They arise from lung buds and are present at birth. The embryonic foregut is their origin. Typically, they are located within the chest cavity, particularly in the cavum mediastinale of the thoracic cavity or lodged in the pulmonary parenchyma, and are considered a type of lung bud malformation. CASE SUMMARY: A 49-year-old male patient was admitted to the hospital due to the detection of a retroperitoneal mass during a physical examination. Two weeks before admission, the patient underwent a physical examination and routine laboratory tests, which revealed a space-occupying mass in the retroperitoneal region. The patient did not report any symptoms (such as abdominal pain, flatulence, nausea, vomiting, high fever, or chills). The computed tomography (CT) revealed a retroperitoneal space-occupying lesion with minimal enhancement and a CT value of approximately 36 Hounsfield units. The lesion was not delineated from the boundary of the pancreatic body and was closely related to the retroperitoneum locally. CONCLUSION: Following a series of tests, an abdominal mass was identified, prompting the implementation of a laparoscopic retroperitoneal mass excision procedure. During the investigation, an 8 cm × 7 cm cystic round-shaped mass with a distinct demarcation was identified in the upper posterior region of the pancreas. Subsequently, full resection of the mass was performed. Postoperative pathological examination reveled a cystic mass characterized by a smooth inner wall. The cystic mass was found to contain a white, viscous liquid within its capsule.

Autopsy findings of fatal retroperitoneal hemorrhage after traumatic rupture of bilateral renal angiomyolipoma.

The present work reports the autopsy findings of a unique case characterized by fatal retroperitoneal hemorrhage following the traumatic rupture of bilateral renal angiomyolipomas. Renal angiomyolipomas are generally benign tumors with an unpredictable clinical course, ranging from asymptomatic to sudden rupture and hemorrhagic shock. They may be associated with genetic disorders such as tuberous sclerosis complex. The case under investigation is unprecedented in the medical literature due to its bilateral nature and fatal outcome. Autopsy analysis revealed an extensive retroperitoneal hemorrhage originating from bilateral ruptured tumors. Microscopic examination found features consistent with bilateral renal angiomyolipoma. Circumstantial information identified a traffic accident before the death, considering it as the cause of the tumors' traumatic rupture. In this case, due to the severity of the situation, immediate medical measures-such as fluid resuscitation, coagulopathy correction, and surgical treatment, which are usually lifesaving-could not be performed. This led to the patient being declared dead at the scene of the crash.

Retroperitoneal abscess associated with closed pelvic ring fracture diagnosed by fine free air on initial trauma pan computed tomography scan.

The patient was a 49-year-old male. He had a closed fracture of the pelvic ring that was treated successfully by avoiding anterior pelvic ring stabilization because of the presence of microscopic free air in the retroperitoneal space behind the pubic bone on initial whole-body trauma computed tomography scan. For his pelvic ring injury, transiliac rod and screw fixation was performed without the need for a pubic symphysis plate by developing the retroperitoneal space. His retroperitoneal abscess was treated by minimally invasive treatment of retroperitoneal abscess with computed tomography-guided percutaneous drainage. At 2 years postoperatively, there was no fever or elevated inflammatory response suspicious of retroperitoneal abscess recurrence. In this case, the presence of microscopic free air influenced the choice of treatment. Even in closed pelvic ring fractures, the presence of free air should be carefully considered when reading images.

Complete retroperitoneal cutaneous ureterostomy with robot-assisted radical cystectomy.

Introduction: Cutaneous ureterostomy is beneficial for older patients in a hypoalimentation state, providing less invasive options than intestinal tract reconstruction techniques. However, complications such as ileus and stoma site hernia still pose risks owing to the anatomical location of the ureter. We introduce a novel method, complete retroperitoneal cutaneous ureterostomy, performed simultaneously with robot-assisted radical cystectomy. Case presentation: Our technique involves extending the retroperitoneal space to minimize complications and achieve stent-free outcomes. The median procedure time for complete retroperitoneal cutaneous ureterostomy was approximately 30 min. The stent-free rates at 1 and 4 months postoperatively were 66.7% and 100%, respectively; no case of stent reinsertion after stent removal was reported. Conclusion: Our approach is promising for avoiding postoperative intestinal tract complications.

Bilateral duplicated inferior vena cava associated with aberrant internal iliac and gonadal veins: A case-based narrative review.

BACKGROUND: The left side anterior retroperitoneal approach is preferred for the management of lumbosacral spine disorders as there is reduced risk for vascular injury. The presence of multiple and uncommon venous variations on either side of the spine, like the bilateral duplicated inferior vena cava (DIVC), may complicate surgery in this region. The current study describes two rare cases of bilateral duplicated inferior vena cava associated with internal iliac and gonadal veins. METHODS: The cases were identified during routine human dissections of the posterior abdominal wall of 89 (45 males, 44 females) individuals. The course, relations and morphometry of each duplicated inferior vena cava were examined and recorded. RESULTS: Two (2.2%) of the 89 (1 male, 1 female) dissected individuals showed the presence of bilateral duplicated infrarenal segments of the inferior vena cava. In both cases, the pre-aortic trunk (vein) was the largest and the left inferior vena cava was the smallest. Both cases of bilateral DIVC presented with anomalous interiliac communicating veins, internal iliac veins, and drainage sites of the left gonadal veins. CONCLUSIONS: The duplicated inferior vena cava may present with associated venous anomalies like those related to the gonadal and internal iliac veins. Knowledge of the duplicated inferior vena cava and its associated venous anomalies may be essential for accurately identifying and diagnosing vascular dysfunction and improving radiological interpretation across multiple surgical specialities.

Retroperitoneoscopy of the presacral space in horses: Surgical access and anatomy.

BACKGROUND: Surgical approaches to the equine rectum and perirectal area are described in the literature. However, surgeries in this region can be challenging. OBJECTIVE: To describe the surgical anatomy of the presacral space and to evaluate its access using a retroperitoneoscopic approach. STUDY DESIGN: Ex vivo experiment. METHODS: Preliminary dissections were performed in two cadavers to define the boundaries of the presacral space and to determine portal locations for the surgical approach. After that, nine cadavers were used for experimental presacral retroperitoneoscopic procedure in a standing position. Following retroperitoneoscopy, cadavers were dissected to confirm the anatomical structures observed during the endoscopic procedures, to control the location of each portal and to record iatrogenic trauma. RESULTS: The presacral space was bordered by the vertebral column from the ventral aspect of lumbosacral promontorium to the first coccygeal vertebra dorsally and by the presacral fascia and peritoneum ventrally. Lateral limits were composed of the sacrosciatic ligament and transversalis fascia. Cranial and caudal borders were composed of the peritoneum and coccygeal and levator ani muscles respectively. Retroperitoneoscopic portals were placed between the external anal sphincter and semimembranosus muscles and between the base of the tail and the external anal sphincter muscle through the anococcygeal fascia to enter the space by its caudal border. The retroperitoneal space was reached in all cases and the dorsal and lateral aspects of the rectum were visualised after creation of a working space. MAIN LIMITATIONS: Use of cadaver specimens do not permit to evaluate the tolerance in living animals and the surgical complications such as rectal damage, haemorrhage and infection. CONCLUSION: This study provides an anatomical description and surgical access of the presacral space with a minimal invasive approach. Retroperitoneoscopy allows access to the rectum and the dorsal aspect of the pelvis.

Autopsy findings of fatal retroperitoneal hemorrhage after traumatic rupture of bilateral renal angiomyolipoma

ABSTRACT The present work reports the autopsy findings of a unique case characterized by fatal retroperitoneal hemorrhage following the traumatic rupture of bilateral renal angiomyolipomas. Renal angiomyolipomas are generally benign tumors with an unpredictable clinical course, ranging from asymptomatic to sudden rupture and hemorrhagic shock. They may be associated with genetic disorders such as tuberous sclerosis complex. The case under investigation is unprecedented in the medical literature due to its bilateral nature and fatal outcome. Autopsy analysis revealed an extensive retroperitoneal hemorrhage originating from bilateral ruptured tumors. Microscopic examination found features consistent with bilateral renal angiomyolipoma. Circumstantial information identified a traffic accident before the death, considering it as the cause of the tumors' traumatic rupture. In this case, due to the severity of the situation, immediate medical measures—such as fluid resuscitation, coagulopathy correction, and surgical treatment, which are usually lifesaving—could not be performed. This led to the patient being declared dead at the scene of the crash.

Development and validation of machine-learning models for the difficulty of retroperitoneal laparoscopic adrenalectomy based on radiomics.

Objective: The aim is to construct machine learning (ML) prediction models for the difficulty of retroperitoneal laparoscopic adrenalectomy (RPLA) based on clinical and radiomic characteristics and to validate the models. Methods: Patients who had undergone RPLA at Shanxi Bethune Hospital between August 2014 and December 2020 were retrospectively gathered. They were then randomly split into a training set and a validation set, maintaining a ratio of 7:3. The model was constructed using the training set and validated using the validation set. Furthermore, a total of 117 patients were gathered between January and December 2021 to form a prospective set for validation. Radiomic features were extracted by drawing the region of interest using the 3D slicer image computing platform and Python. Key features were selected through LASSO, and the radiomics score (Rad-score) was calculated. Various ML models were constructed by combining Rad-score with clinical characteristics. The optimal models were selected based on precision, recall, the area under the curve, F1 score, calibration curve, receiver operating characteristic curve, and decision curve analysis in the training, validation, and prospective sets. Shapley Additive exPlanations (SHAP) was used to demonstrate the impact of each variable in the respective models. Results: After comparing the performance of 7 ML models in the training, validation, and prospective sets, it was found that the RF model had a more stable predictive performance, while xGBoost can significantly benefit patients. According to SHAP, the variable importance of the two models is similar, and both can reflect that the Rad-score has the most significant impact. At the same time, clinical characteristics such as hemoglobin, age, body mass index, gender, and diabetes mellitus also influenced the difficulty. Conclusion: This study constructed ML models for predicting the difficulty of RPLA by combining clinical and radiomic characteristics. The models can help surgeons evaluate surgical difficulty, reduce risks, and improve patient benefits.

Value of Non-Contrast-Enhanced Vessel Wall MR Imaging in Assessing Vascular Invasion of Retroperitoneal Tumors.

BACKGROUND: Due to their location and growth patterns, retroperitoneal tumors often involve the surrounding blood vessels. Clinical decisions on a proper treatment depend on the information on this condition. Evaluation of blood vessels using non-contrast-enhanced vessel wall MRI may provide noninvasive assessment of the extent of tumor invasion to assist clinical decision-making. PURPOSE: To investigate the performance and potential of non-contrast-enhanced vessel wall MRI in evaluating the degree of vessel wall invasion of retroperitoneal tumors. STUDY TYPE: Prospective. POPULATION: Thirty-seven participants (mean age: 60.59 ± 11.77 years, 59% male) with retroperitoneal tumors close to vessels based on their diagnostic computer tomography. FIELD STRENGTH/SEQUENCES: 3 T; vessel wall MRI sequences: two-dimensional T2-weighted MultiVane XD turbo spin-echo (2D-T2-MVXD-TSE) and three-dimensional T1-weighted motion sensitized driven equilibrium fat suppression turbo spin-echo (3D-T1-MSDE-TSE) sequences; conventional MRI sequences: T2-weighted fat suppression turbo spin-echo (T2-FS-TSE), T2-weighted turbo spin-echo (T2-TSE), modified Dixon T1-weighted fast field echo (T1-mDixon-FFE), and diffusion-weighted echo planar imaging (DWI-EPI) sequences. ASSESSMENT: All patients underwent preoperative imaging using both non-contrast conventional and vessel wall MRI sequences. Images obtained from conventional and vessel wall MRI sequences were evaluated independently by three junior radiologists (3 and 2 years of experience in reading MRI) and reviewed by one senior radiologist (25 years of experience in reading MRI) to assess the degree of vessel wall invasion. MRI were validated results from the clinical standard diagnosis based on surgical confirmation or histopathological reports. Interobserver agreement was determined based on the reports from three readers with similar years of experiences. Intraobserver variability was assessed based on categorizing and recategorizing the vessels of 37 patients 1 month apart. STATISTICAL TESTS: Intra-class correlation efficient (ICC), Chi-square test, McNemar test, area under the receiver-operating characteristic curve (AUC), Delong test, P < 0.05 was considered significant. RESULTS: The accuracy of vessel wall MRI (91.96%, 95% CI: 85.43-95.71; 103 of 112) in detecting the degree of vessel wall invasion was significantly higher than that of conventional MRI (75%, 95% CI: 66.24-82.10; 84 of 112). The interobserver variability or reproducibility in categorization of the degree of vascular wall invasion was good in evaluating images from conventional and vessel wall MRI sequences (ICC = 0.821, 95% CI: 0.765-0.867 and ICC = 0.881, 95% CI: 0.842-0.913, respectively). DATA CONCLUSION: Diagnosis of vessel wall invasion of retroperitoneal tumors and assessment of its severity can be improved by using non-contrast-enhanced vessel wall MRI. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.

Solitary Fibrous Tumor in the Retroperitoneal Space Arising from the Diaphragm.

BACKGROUND/AIM: We present a case of solitary fibrous tumor, arising from the diaphragm in the retroperitoneal space, that was resected with robotic assistance. CASE REPORT: An 85-year-old female patient was referred to our hospital for evaluation of a suspected right renal tumor. Abdominal contrast-enhanced computed tomography revealed a tumor (maximum diameter, 36 mm) protruding from the superior pole of the right kidney. The patient was scheduled for robot-assisted, retroperitoneoscopic, partial nephrectomy based on a preoperative diagnosis of renal cell carcinoma. Intraoperative findings revealed that the tumor originated from the diaphragm and had no continuity with the renal parenchyma. Pathological examination revealed a solitary fibrous tumor. CONCLUSION: Solitary fibrous tumors are rare soft-tissue neoplasms with a distinct molecular feature of the fusion of nerve growth factor-inducible A gene-binding protein 2 with signal transducer and activator of transcription 6 gene (NAB2::STAT6). We believe that this is the first reported case of a solitary fibrous tumor arising from the diaphragm in the retroperitoneal space.

Anterior pushing technique for a broken scalpel blade in lumbar discectomy: a case report.

The presence of broken surgical blades or other surgically uncontrolled sharp and pointed objects in the disc space is a rare but potentially severe complication of posterior lumbar spine procedures. Herein, we report the case of a 59-year-old female patient with a history of lumbar decompression and interspinous process device implantation who underwent an instrumented revision of the lumbosacral junction. During the L5-S1 discectomy, the scalpel blade broke, and the broken fragment could not be retrieved through the posterior approach. With regard to the vascular anatomy, we partially pushed the fragment through the anterior annulus into the retroperitoneal space. In addition, pedicle screws were locked to ensure the stability of the construct. The fractured blade fragment was eventually removed by laparoscopy 1 week after the initial procedure. This experience suggests that the anterior pushing technique with fluoroscopy is an option in rare cases where a broken scalpel blade cannot be reached through the posterior approach. In such cases, computed tomography angiography is recommended.

Multivisceral resection for retroperitoneal liposarcoma-is it worth it? A 20-year single-center experience.

PURPOSE: Soft tissue sarcomas are rare malignant tumors. Liposarcoma constitutes the most frequent histological subtype of retroperitoneal sarcoma. The prognosis of soft tissue sarcomas depends on clinical and histologic characteristics. OBJECTIVE: Evaluate variables that may be related to the overall and local recurrence-free survival in patients with retroperitoneal liposarcoma and discuss the need for visceral resection en-bloc for tumors. METHODS: A retrospective analysis was conducted of the medical records of 60 patients seen between 1997 and 2017 who underwent surgical resection of retroperitoneal liposarcoma. RESULTS: The overall survival rate at 5 years of follow-up was 75.22% (95% confidence interval [CI] 0.58-0.86). The probability of a local recurrence-free survival at 5 years of follow-up was 26.04% (95% CI 0.11-0.44). The multivariate analysis showed that dedifferentiated or pleomorphic tumors and R2/fragmented resection were associated with a shorter time to recurrence. No other characteristics markedly influenced the overall survival (P > 0.05). CONCLUSION: Patients with dedifferentiated or pleomorphic tumors and incomplete resection were associated with higher local recurrence rates than others. This study reinforces the need for complete and en-bloc resection with organs when there is clear involvement or technical surgical difficulty to maintain the tumor integrity.

Simultaneous adrenal and retroperitoneal myelolipoma resected by laparoscopic surgery: a challenging case.

BACKGROUND: Myelolipoma is a benign neoplasm of the adrenal cortex, composed of fat and hematopoietic cells. Although myelolipoma is benign, differentiation from adrenocortical cancer may be difficult. The presence of adrenal and extra-adrenal myelolipomas simultaneously is sporadic, making it a challenging case, especially when the preoperative diagnosis is ambiguous. CASE PRESENTATION: A 65-year-old man was referred to our clinic due to a mass in the adrenal fossa. In the abdominopelvic computed tomography (CT), a well-circumscribed fat-containing 78 × 61 × 65 mm bi-lobulated mass was reported in the left adrenal fossa. The first differential diagnosis was myelolipoma. The patient was then referred to our clinic for a mass excision. He was asymptomatic and was scheduled to undergo laparoscopic-assisted adrenalectomy. After adrenalectomy and mass dissection, surprisingly, another mass was detected in the retroperitoneal area. The second mass was also dissected. The final diagnosis was myelolipoma for both masses. The patient has been symptom-free for nine months after the operation. CONCLUSION: Simultaneous adrenal and extra-adrenal myelolipoma should be considered as one of the differential diagnoses. However, because this situation is extremely rare, the probability of malignancy should be highly regarded, and we suggest an obsessive approach when approaching this condition. It is essential to manage these cases on a case-by-case basis and tailor the management concerning intraoperative biopsy, the intraoperative appearance of tumors, and the location of extra-adrenal masses.