Retroperitoneal Lipoma Research Articles

Preoperative Contrast-Enhanced CT-Based Deep Learning Radiomics Model for Distinguishing Retroperitoneal Lipomas and Well‑Differentiated Liposarcomas

ObjectivesTo 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. MethodsThis retrospective multi-centre 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). ResultsThe 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. ConclusionsThe 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.

Adrenal Myelolipoma: Case Report

Introduction: Myelolipomas were first described in 1905 as an adrenal tumor composed of mature fat mixed with myeloid and erythroid cells. Adrenal myelolipomas are the second most common benign type of tumor in the adrenals, following after adrenocortical adenomas. It is mostly discovered incidentally on imaging of abdomen done for non-adrenal related reasons or at autopsy. Symptomatic tumors, growing tumors or tumors larger than 10 cm should be excised surgically. We report the case of 1 male patient presenting with flank pain and upper pole renal masse, treated surgically with adrenalectomy. Myelolipoma was confirmed on histology. Case presentation: a 46-years-old male, with a history of blood hypertension, presented with persistent abdominal discomfort and occasional pain in the right flank region. Physical examination revealed a non-tender palpable mass in the right upper quadrant of the abdomen. The abdominal CT scan revealed a large well-defined retroperitoneal tumor, which compressed and displaced the right kidney downward, the mass was heterogeneous with areas of soft-tissue attenuation. The patient underwent open left adrenalectomy. The pathological study confirmed the diagnosis of adrenal myelolipoma. The differential diagnosis of fat-containing retroperitoneal masses would include retroperitoneal lipoma or liposarcoma and renal angiomyolipoma. Discussion: Adrenal myelolipomas are the second most common adrenal incidentalomas comprising 6 to 16% of adrenal incidentalomas. The size of adrenal myelolipomas is variable and can range from a few millimeters to greater than 10 cm. These are called giant adrenal myelolipomas. The largest adrenal myelolipoma reported to date weighed 6 kg. Extra-adrenal sites for myelolipomas include the retroperitoneum, thorax, and pelvis. Usually unilateral however they can also involve both adrenals. The most common symptoms observed are abdominal discomfort/pain, hypochondrial pain, and flank pain. Ultrasonography (USG), ......

Intra-Abdominal and Retroperitoneal Benign Lipomatous Tumors-An Extremely Rare Mimic of Liposarcoma and its Diagnostic Challenge.

Background. Lipomas are common superficial soft tissue tumors of mature adipocytes. In contrast, well-differentiated/dedifferentiated liposarcoma typically presents in the retroperitoneum as large masses. We provide clinicopathologic and follow-up details of 9 retroperitoneal/intra-abdominal benign lipomatous tumors (BLT) and discuss the utility of ancillary fluorescence in situ hybridization (FISH) in distinguishing from their malignant counterparts. Design. Clinicopathologic details and histology of 9 intra-abdominal and retroperitoneal lipomas were studied along with ancillary CD10 immunohistochemistry (IHC) and FISH for MDM2 and CDK4 amplification. Results. There were 6 females and 3 males. Median age at diagnosis was 52 years (range 36-81 years). Seven were identified incidentally and 2 presented with primary complaints. On imaging, 7 were considered suspicious for liposarcoma. Grossly, the tumors ranged from 3.4 to 41.2 cm (median 16.5 cm). Histologically, all cases showed well-differentiated BLT, further classified as lipoma (n = 7; 1 with metaplastic ossification, 2 with prominent vessels, and 4 ordinary lipomas) and lipoma-like hibernoma (n = 2)-the latter 2 showed intramuscular lesions with interspersed brown fat. CD10 IHC showed strong staining in the 2 hibernomas, whereas the staining was weak in the remaining. MDM2 and CDK4 amplification were negative by FISH in all. Follow-up (median 18 months) did not show recurrence on clinical or imaging evaluation. Conclusion. Retroperitoneal/intra-abdominal BLT are extremely rare and are indistinguishable clinically and radiographically from liposarcoma. This necessitates molecular confirmation even when the histology is convincingly benign, for a confident diagnosis. Our cohort shows that conservative excision without removal of abutted organs is sufficient in most cases.

RETROPERITONEAL LIPOMAS PRESENTING AS INGUINAL HERNIA – A DIAGNOSTIC DILEMMA

Introduction - Retroperitoneal lipomas rarely present as inguinal hernia. The part of the tumour that herniates represents only the tip of the iceberg as the main part of herniated mass is not detected clinically. - A Case discussion 60-year-old male presented with complaints of pain over irreducible swelling in left inguinoscrotal region for 3 days which was present for 2 years. Lump was palpable of size ~20x10x7 cm with mild tenderness with ultrasonography suggestive of left inguinal hernia with 2.8 cm defect with bowel and omentum as content with sluggish peristalsis. Patient was posted for hernia repair through inguinal incision with intraoperative ndings where sac could not be visualised with irreducible contents. Hence exploratory laparotomy was done and mass was found to originate from retroperitoneum of size ~ 30 x15x10 cm encasing left testes. Enbloc resection of the retroperitoneal lipoma with left orchidectomy done and sent for histopathology which was suggestive of Retroperitoneal Multilobular Lipoma. - The presented case points out that abdomi Conclusion nal lipomas can be misdiagnosed as irreducible inguinal hernia. Not all groin masses are simple hernias, and hernia cases have the potential to reect distant disease processes.

A systematic literature review of diagnostic and treatment approaches of retroperitoneal lipoma

Background: Retroperitoneal lipomas are a rare condition, posing challenges for the appropriate diagnosis, treatment and management. Usually these neoplasms are asymptomatic for a long time before they cause symptoms due to shifting of adjacent structures and organs. Preoperative diagnosis remains still a challenge due to difficulties in differential diagnosis with retroperitoneal liposarcoma. Therefore, we conducted a systematic literature review, according to PRISMA guidelines, aiming to understand the current diagnostic and treatment approaches.

ЛИПОМА КАК СЛУЧАЙНАЯ НАХОДКА В АБДОМИНАЛЬНОЙ ХИРУРГИИ

Primary neoplasms of the abdominal cavity are rare and usually have a mesenchymal origin. Lipoma is a benign mature tumor of adipose tissue, it occurs more often in women aged 30 to 50 years. Retroperitoneal lipoma is a rare variant of lipoma, manifested by various signs and symptoms that can mislead specialists. Lipomas are more common in abdominal surgery in the gastrointestinal tract. In this localization, the main pathognomonic complication is intestinal intussusception. Diagnosis is difficult, due to the relatively slow growth of education, characteristic clinical manifestations may be absent for a long time. X-ray imaging is the preferred diagnostic method. To date, surgical resection is the priority method of treatment of this pathology. The analysis of scientific literature on the occurrence of abdominal lipomas is carried out. The diagnostic significance in assessing the condition and complications of lipomas has been studied. Clinical cases from personal practice on the basis of the State Clinical Hospital named after him are presented. Yudina. Patients with diagnoses of giant retroperitoneal lipoma and complicated small intestine lipoma by female intussusception aged 62 and 78 years, respectively. The first clinical case demonstrates the randomness of the determination of lipoma in a patient admitted to the clinic with a closed craniocerebral injury and a wound of the soft tissues of the head. Ultrasound of the abdominal cavity showed the presence of a large retroperitoneal formation of an inhomogeneous consistency. During laparotomy, a giant fatty tumor with clear boundaries was revealed, closely adjacent to the adipose tissue of the retroperitoneal space. Lipoma was removed, drainage of the abdominal cavity and retroperitoneal space was performed. Histopathological examination confirmed the diagnosis of retroperitoneal lipoma. The weight of the lipoma was 10.610 kg. The postoperative period proceeded without complications. The second clinical case shows how a long-term undiagnosed lipoma of the gastrointestinal tract leads to a complicated course, namely intussusception. Patient A. 78 years old with discomfort and abdominal pain during the last few weeks, small intestine invagination was detected using ultrasound. Diagnosis upon admission: acute pancreatitis. A resection of the altered section of the small intestine was performed. The postoperative period was favorable. The patient was discharged on the 10th day. The presented clinical cases of this disease once again confirm the importance of timely dispensary diagnosis of abdominal tumors.

Retroperitoneal lipoma in pregnancy: Between surgical intervention and postpartum deferral.

Timing of retroperitoneal tumor resection in pregnancy should be guided by patient symptoms, gestational age, and radiologic features to minimize potential maternal and fetal morbidity.

En-block resection of a giant retroperitoneal lipoma presented as huge abdominal swelling: a case report

Retroperitoneal lipomas are an extremely rare entity with only less than 20 cases described in the literature so far. They can attain immoderate size due to space provided in the retroperitoneum and cause abdominal symptoms like abdominal pain, swelling and obstipation due to mass effect. Case presented here as of 53 years old male with complaint of abdominal swelling that had been progressive for the last 1 year. On computed tomography (CT) it revealed giant retroperitoneal mass? liposarcoma? occupying the space immensely. Intraoperatively, two giant retroperitoneal tumours were found which did not show any features of infiltration to nearby structures, therefore the sole tumour annihilation was achieved, which was diagnosed as benign lipoma on histopathology report later. The most important differential diagnosis is the well differentiated liposarcoma, which could only be confirmed after resection and histopathological assessment. Retroperitoneal lipomas are clearly not distinguishable from well differentiated liposarcomas on CT guided and USG guided biopsy and thus it could be misleading. Hence surgical resection with negative margins along with histopathological confirmation is treatment of choice with regular follow up to diagnose early recurrence if any.

1003 A Case of Tunnel-Vision in Upper Renal Tract Imaging: The Invisible Gorilla

Abstract We present an interesting case of a 70-year-old female who presented with haematuria on the suspected cancer pathway. Renal ultrasound showed a vascular renal mass on her right kidney measuring 8x7cm with an unremarkable left kidney. She underwent a laparoscopic radical nephrectomy following confirmation of an 8cm renal mass in the right kidney on the contrasted staging CT scan with a repeat review at the multidisciplinary meeting. Post-operatively a subsequent review of the pre-operative CT and ultrasound scan, showed an incidental large left(contralateral) upper quadrant retroperitoneal fatty mass sized 15x10cm, displacing the stomach and spleen. Further investigation in the form of an MRI Abdomen excluded features of a liposarcoma, resulting in the diagnosis of a large retroperitoneal lipoma. This case highlights the significance of selective attention in imaging interpretation. We believe this to be a prime example of the level of meticulousness required as fat-rich tissues have low attenuation on CT-scans, which can be easily missed out. A cautious multi-clinician interpretation of scans should be performed to avoid missing potentially sinister pathology which would impact patient care dramatically. This case has led to more thorough review of future pre-operative imaging by the operating surgical team.

¿Lipoma gigante o liposarcoma retroperitoneal? Controversias en su diagnóstico y tratamiento

BackgroundRetroperitoneal lipomas are extremely rare tumors that must be differentiated from well-differentiated liposarcomas (WD-LPS). ObjectivesTo summarize the evidence about giant retroperitoneal lipomas or liposarcomas; and to elaborate recommendations for their management. Data sourcesA systematic literature search from January 1985 to December 2019 and a review of our own cases was performed. ResultsOur series comprises four patients, two females and two males. The diagnosis was incidental in two cases. The medium size was 26 cm, being two cases located exclusively in the retroperitoneum, one in the inguinal region and one in the buttock via pelvic space. All cases were surgically removed being confirmed the initial diagnosis of retroperitoneal lipomas in two cases, as the rest two cases were classified as WD_LPS after MDM2/CDK4 genetic analysis.The review of the available literature plus our own cases revealed 30 cases, of which 58% were woman. Only two cases were asymptomatic. The main symptom was abdominal mass (53%) followed by abdominal pain (40,6%). The median size of the lesions was 24,9 cm with a median weight of 4.576,3 g. All cases were surgically removed, being necessary to remove contiguous organs in only four cases (12,5%). ConclusionsRetroperitoneal lipoma is a rare tumor which must be differentiated from WD-LPS. This is a very difficult task, being necessary to determinate MDM2 status (by FISH or MLPA), present in liposarcoma but not in lipomas, for its correct diagnosis. The treatment must be based on a complete surgical resection with negative margins.

Giant retroperitoneal lipoma in a child: clinical case

Retroperitoneal lipoma is extremely rare in pediatric practice. This article describes the diagnosis and treatment tactics of a clinical case of retroperitoneal lipoma in a 4- year-9-month-old child. The operative intervention is a rational method of this disease treatment.

Giant retroperitoneal lipoma presenting as abdominal protrusion: One case report and review of literature

AbstractLipomas are benign tumors of mature adipocytes, which are commonly located in the subdermal tissue of the trunk or extremities. Deep‐seated lipomas, especially originating from the retroperitoneal space, are extremely rare. We present the case of a 57‐year‐old man with a giant retroperitoneal lipoma but without impaired gastrointestinal (GI) function. This patient visited the GI outpatient clinic for progressively distended abdomen in the preceding months. The patient denied experiencing any nausea, loss of appetite, abdominal pain, and change of bowel habits. Physical examination demonstrated a soft, nontender protrusion in the abdomen without guarding. Further analysis via dynamic liver computed tomography scan indicated a large, fat‐attenuated, mass‐like lesion in the left upper abdomen. In order to rule out malignant fat‐containing retroperitoneal masses, the patient underwent resection of the retroperitoneal and intra‐abdominal tumor. It is quite important to analyze the characteristics of the tumor accurately in order to make subsequent decisions on how to proceed with the surgery.

Giant retroperitoneal lipoma in a child misdiagnosed as Hirschsprung's disease

Retroperitoneal lipomas have remained the essentially rare tumors seen in clinical practice. The tumors are rarer in children, with very few reported cases in surgical literature worldwide. We report the case of a 5-year-old child who presented with a giant retroperitoneal lipoma that was successfully managed by complete excision. There has been no recurrence noticed during follow-up. We present a rare case of giant retroperitoneal lipoma in a child. At laparotomy, a giant lipoma weighing about 6 kg was excised.

74] Giant retroperitoneal lipoma: A case report and review of the literature

ObjectiveTo report on a very rare case of giant retroperitoneal lipoma and a literature review. Retroperitoneal lipomas are an extremely rare condition with only 17 cases described in the literature since 1980. They can reach enormous size and cause significant abdominal symptoms. The most important differential diagnosis is the well-differentiated liposarcoma, which preoperatively often may not definitely be ruled out.

Tumoral retroperitoneal masses and their impact to renal function

Abstract Retroperitoneal tumors, either benign or malignant, usually cause problems both for an accurate diagnosis and for therapeutic approach, due to their reduce incidence, late presentation and anatomical location, in the neighborhood of vital structures from the retroperitoneal space. Materials and methods: Aim of study was to search correlations between, gender, age, and histo-pathological type of retroperitoneal tumors, as well as their impact upon renal function. Results: Sarcomas represented about 30% of retroperitoneal tumors. The most frequent benign retroperitoneal tumors included: neurogenic tumors, paragangliomas, renal angiomyolipomas and benign retroperitoneal lipomas. Renal function was altered in about 55% of the patients, and postsurgical mortality was 8.73%.

A giant retroperitoneal lipoma presenting as a sciatic hernia: MRI findings

Sciatic hernia is a rare condition and its clinical diagnosis is uneasy. Herniation of pelvic organs as well as of retroperitoneal neoplasm has been reported in the literature. Sciatica occurs as a result of compression of the sciatic nerve by the herniated sac. We present a case of retroperitoneal lipoma in a patient who had lower leg complaint and describe the imaging findings.

Successful simultaneous laparoscopic management of large retroperitoneal lipoma and chronic gallstone cholecystitis

Successful simultaneous laparoscopic management of large retroperitoneal lipoma and chronic gallstone cholecystitis

Intestinal Ganglioneuromatosis: Unusual Presentation of Cowden Syndrome Resulting in Delayed Diagnosis

We report on a 25-year-old woman who presented as a teenager with macrocephaly and multiple gastrointestinal lesions including ganglioneuromas, hamartomas, lipomas, juvenile, and hyperplastic polyps in association with extra-intestinal tumors including a retroperitoneal lipoma, storiform collagenoma, and a fibrolipomatous hamartoma. PTEN mutation analysis identified a deletion in exon 2, confirming the diagnosis of Cowden syndrome. While intestinal polyps are common among Cowden patients who undergo endoscopy, and intestinal ganglioneuromas are occasionally reported, they are not usual presenting manifestations. Intestinal ganglioneuromatosis is divided into three subgroups: (1) polypoid ganglioneuromatosis (usually few isolated ganglioneuromas), (2) generalized ganglioneuromatosis (usually associated with NF1 or MEN), and (3) ganglioneuromatous polyposis without known systemic disease, although there are several reported patients with multiple lipomas. This individual with Cowden syndrome closely resembles the latter group, thus we suggest that patients with ganglioneuromatous polyposis, especially in association with lipomas, should be evaluated for possible Cowden syndrome.

Pelvic Lipoma in a Case of Stage-II Cervical Carcinoma - A Case Report

Retroperitoneal pelvic lipomas are so rare that there are only few cases reported in literature. Current imaging techniques such as USG, CT & MRI are helpful in diagnosis. A case of pelvic lipoma in a patient with stage-II cervical carcinoma is described. Initial ultrasound showed an irregular mass in the cervix with suggestion of an echogenic lesion in left side of pelvis. Plain and contrast enhanced CT showed a homogenous fat attenuation mass in the left side of pelvis with a faintly visible capsule which did not enhance post contrast. MRI permitted unequivocal diagnosis of lipoma. The usefulness of various imaging methods is discussed in correctly diagnosing the entity and avoiding unnecessary surgery in asymptomatic patient.

Retroperitoneal Lipoma Presenting with Nutcracker-Like Phenomenon

Retroperitoneal lipoma presenting with a nutcracker-like phenomenon is extremely rare. I experienced a case of a 65-year-old man presenting with left flank pain and macrohematuria intermittently for 3 years. Computed tomography revealed a lipoma at the left pedicle of the kidney, 30 mm in diameter, causing a curving of the left renal artery and dilatation of the left renal vein. This patient was treated successfully by retroperitoneoscopic resection of the lipoma. There have been no symptoms for 10 years after the operation.