Surgical management of lipoblastoma

A case of lipoblastoma in a pediatric patient

Lipoblastoma is a benign soft tissue tumor that originates from embryonic white fat. Lipoblastoma presents as a slow-growing mass that commonly occurs in the extremities of young children. Histological examination remains the gold standard in confirming lipoblastoma; however, radiology examination can help identify and evaluate the extent and characterization of the mass prior to the excision. Here, we report a 7-year-old male patient who presented with a painless mass in the right popliteal extending to the proximal cruris areas, and the imaging modalities suggested the presence of fat within the mass. The patient then underwent complete excision, and histopathology examination revealed lipoblastoma. This study highlights the possibility of lipoblastoma in older children and the role of imaging examinations in the diagnosis.

A giant gluteal lipoblastoma in a 24-month-old girl: A case report

INTRODUCTION AND IMPORTANCE

Lipoblastomas are rare benign tumors that arise from embryonic white fat and almost always occur in babies and children.

CASE PRESENTATION

Here, we report a case of a giant gluteal lipoblastoma in a 24-month-old girl that was successfully treated via complete resection.

CLINICAL DISCUSSION

The gluteal location as in this case is an exceptional location. These tumors generally are benign, and there have been no reports of metastasis. Local recurrence can occur, particularly with lipoblastomatosis, when excision is incomplete. Surgical resection is the treatment of choice. The goal is always complete resection with negative margins, but this can be difficult to obtain with lipoblastomatosis. No spontaneous resolution or reduction of lipoblastoma has ever been reported, and a recurrence rate of 14 % and 25 % is reported in cases of incomplete excision.

CONCLUSION

Lipoblastoma is a benign neoplasm of immature fat tissue occurring in infants. The gluteal region location is relatively rare. Imaging, especially MRI, is helpful in diagnosis and preoperative evaluation. An adequate pathological examination could bring huge benefits. Total surgical resection is the treatment of choice. Subtotal resection and "wait and see policy" may be discussed for highly risky intervention.

Head and neck lipoblastoma in children: A case report and systematic review

BACKGROUND

Lipoblastoma is a rare and benign tumor arising from embryonal fat cells. It develops primarily in infancy and early childhood. We present a case study of a 10-month-old child treated for an extensive tumor of the infratemporal fossa and parapharyngeal space. The systematic review of 60 reports in 80 children with lipoblastoma of the head and neck is also reported.

MATERIAL AND METHODS

Systematic review of all articles included lipoblastomas of the head and neck area in children published from 1964 to 2022 in the PubMed database was conducted. Clinical presentation of extensive lipoblastoma of the head and neck in a child.

RESULTS

On the basis of all inclusion criteria 83 articles were identified concerning pediatric lipoblastoma. There were 36 F (45%) and 39 M (48%), in 6 patients, (7%) gender was not specified. Ages ranged from 0mth (6h) to 15 yo (180mth). The tumor was located in the head in 22 (27%) cases, while the neck area accounted for 53 (65%) cases. General description without precise location was shown in 6 (7%) cases. All patients underwent complete surgical excision. Post surgical recurrence was noted in 6% clinical cases in the analyzed articles.

CONCLUSIONS

Lipoblastoma is characterized by a rapidly growing predominantly adipose mass. The treatment of choice is complete surgical excision. In selected cases when the pathology is hard to reach, as a consequence of the extensive penetration of the mass, we recommend performing the procedure with an interdisciplinary team. Endoscopy assistance and microdebrider significantly facilitated the removal of pathology in the described advanced case of lipoblastoma. This is the only case reported in the pediatric literature of a head and neck lipoblastoma, where due to extensive involvement and location of the disease the cranial nerves V2 and inferior alveolar branch of V3 could not be spared. Long-term follow-up even to 10 years is required because there is a reported tendency for these tumors to recur.

Cardiac and Pericardial Neoplasms in Children: Radiologic-Pathologic Correlation

Primary cardiac and pericardial neoplasms are rare in the pediatric population and can include both benign and malignant lesions. Rhabdomyomas, teratomas, fibromas, and hemangiomas are the most common benign tumors. The most common primary cardiac malignancies are soft-tissue sarcomas, including undifferentiated sarcomas, rhabdomyosarcomas, and fibrosarcomas. However, metastatic lesions are more common than primary cardiac neoplasms. Children with primary cardiac and pericardial tumors may present with nonspecific cardiovascular symptoms, and their clinical presentation may mimic that of more common nonneoplastic cardiac disease. The diagnosis of cardiac tumors has recently been facilitated using noninvasive cardiac imaging. Echocardiography is generally the first-line modality for evaluation. Cardiac MRI and CT are used for tissue characterization and evaluation of tumor size, extension, and physiologic effect. The varied imaging appearances of primary cardiac neoplasms can be explained by their underlying abnormality. Treatment of these lesions varies from conservative management, with spontaneous regression of some lesions such as rhabdomyomas, to surgical resection, particularly in patients with associated heart failure. With adequate imaging techniques and knowledge of the pathologic basis of the neoplasm, it is often possible to differentiate benign from malignant tumors, which can greatly affect adequate and timely treatment. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Lipoblastomatosis Extended into the Lumbar Spinal Canal in a Child: A Case Report

INTRODUCTION

Lipoblastoma and lipoblastomatosis are rare benign mesenchymal adipose tumors that originate from embryonic white adipocytes and occur most commonly in infancy and early childhood. Lipoblastomas occur in the extremities and trunk, including the retroperitoneum and peritoneal cavity. Therefore, infiltration into the spinal canal has rarely been reported.

CASE PRESENTATION

A 4-year-old girl presented to our clinic because of difficulty sitting on the floor with her legs straight. She also complained of enuresis and constipation for the past 6 months with persistent headaches and back pain evoked by body anteflexion. A magnetic resonance imaging revealed a massive lesion of the psoas major muscle, retroperitoneal, and subcutaneous spaces, extending into the spinal epidural space between L2 and S1. The patient underwent surgery which resulted in gross total removal of the tumor from the spinal canal. The mass was yellowish, soft, lobulated, fatty, and easily removed from the surrounding structures. Pathology confirmed the diagnosis of lipoblastoma. The postoperative course was uneventful, and the patient was discharged without any signs of neurological deficit.

CONCLUSION

We herein discuss a rare case of lipoblastoma extending into the spinal canal, resulting in neurological symptoms. Although this tumor is benign with no potential for metastasis, it is prone to local recurrence. Therefore, close postoperative observation should be performed.

A Giant Compressive Mesenteric Lipoblastoma Initially Suspected to Be Abdominal Malignancy: A Report of a Rare Case in a Nine-Month-Old Infant

Lipoblastoma is a rare benign soft tissue neoplasm rising from embryonic white adipose tissue known as lipoblast that keeps proliferating during the postnatal period. Although lipoblastomas are benign, they often grow rapidly. Most lipoblastomas are asymptomatic at presentation; they can present as a growing painless palpable mass and progressive symptoms of various organ compression depending on localization. A giant mesenteric lipoblastoma is a rare case with only a few cases reported. An infant with large intraabdominal masses may present preoperative diagnostic difficulties. Differential diagnoses are broad and may include sarcomas, germ-cell tumors, lipomas, lymphomas, hepatoblastomas, Wilm's tumors, and neuroblastomas. Thorough clinical, radiological, and pathological investigations are ultimately required to obtain a definitive diagnosis. Regardless of location, the treatment of choice for lipoblastoma is complete surgical resection. All patients should be followed up for a minimum of five years We report a rare case of a giant compressive mesenteric lipoblastoma that was initially suspected as abdominal malignancy in a nine-month-old infant. As physicians, we must always consider the underlying cause as well as the malignant or benign nature of a growing mass to treat the patient appropriately.

Lipoblastoma in one adult and 35 pediatric patients: Retrospective analysis of 36 cases

Lipoblastoma is a rare benign mesenchymal neoplasm that typically occurs at various sites in infants and children but may also occur in adults. Thus, differential diagnoses are often performed. To understand this tumor type, the present study described clinicopathological features, diagnosis and differential diagnosis of different morphological lipoblastomas. A single-institution retrospective review of 36 lipoblastoma cases diagnosed between 2015 and 2021 was performed. Formalin-fixed paraffin-embedded tissue was used for S-100, CD34, P16 and desmin immunohistochemistry analysis, along with rapid fluorescence in situ hybridization (FISH) detection with pleiomorphic adenoma gene 1 (PLAG1). The 36 cases included 14 females and 22 males [age range, 7 days to 33 years (median, 16.5 years); 28 patients were aged ≤3 years] and the tumors were located in the trunk (n=16), limbs (n=12), head and neck (n=6), and perineum (n=2). Histologically, lipoblastomas were divided into classic (n=15), lipoma-like (n=13) and myxoid (n=8) subtypes. They comprised lobules of mature adipose tissue of varying size and a fine capillary network surrounded by mucinous stroma. Single- or multivesicular lipoblasts positive for S-100 (29/36, 81%) were observed, with occasional mature adipocytes. Peripheral vessels and cytoplasm of primitive mesenchymal cells were diffusely positive for CD34 (36/36, 100%), whereas primitive mesenchymal cells and striated muscle tissue were positive for desmin (26/36, 72%). Most tumor cells were negative while only few were positive for P16 (8/36, 22%). FISH revealed PLAG1 breakage and rearrangement in 24/32 (75%) patients. In total, 28 patients were followed up post-operatively (range, 2-84 months; median, 41 months; 3 patients relapsed and 8 were lost to follow-up). In conclusion, diagnosis of a typical lipoblastoma is not difficult and PLAG1 breakage detection is key for the diagnosis.

PLAG1 Immunohistochemical Staining Is a Surrogate Marker for PLAG1 Fusions in Lipoblastomas

BACKGROUND

The hallmark of lipoblastoma is a PLAG1 fusion. PLAG1 protein overexpression has been reported in sporadic PLAG1-rearranged lipoblastomas.

METHODS

We evaluated the utility of PLAG1 immunohistochemical staining (IHC) in 34 pediatric lipomatous tumors, correlating the results with histology and conventional cytogenetics, FISH and/or next generation sequencing (NGS) results.

RESULTS

The study included 24 lipoblastomas, divided into 2 groups designated as "Lipoblastoma 1" with both lipoblastoma histology and PLAG1 rearrangement (n = 16) and "Lipoblastoma 2" with lipoblastoma histology but without PLAG1 cytogenetic rearrangement (n = 8), and 10 lipomas with neither lipoblastoma histology nor a PLAG1 rearrangement. Using the presence of a fusion as the "gold standard" for diagnosing lipoblastoma (Lipoblastoma 1), the sensitivity of PLAG1 IHC was 94%. Using histologic features alone (Lipoblastoma 1 + 2), the sensitivity was 96%. Specificity, as defined by the ability to distinguish lipoma from lipoblastoma, was 100%, as there were no false positives in the lipoma group.

CONCLUSIONS

Cytogenetics/molecular testing is expensive and may not be ideal for detecting PLAG1 fusions because PLAG1 fusions are often cytogenetically cryptic and NGS panels may not include all partner genes. PLAG1 IHC is an inexpensive surrogate marker of PLAG1 fusions and may be useful in distinguishing lipoblastomas from lipomas.

Imaging of head and neck lipoblastoma: case report and systematic review

Lipoblastoma is a rare and benign tumour arising from embryonal fat cells, predominantly diagnosed in children younger than 3 years old. The most frequent locations are the extremities and trunk, while the head and neck areas are more rarely affected (10-15% of total cases). Clinically, the most common presentation is a fast-growing painless mass. Ultrasound is the first-line imaging examination, but Magnetic Resonance Imaging (MRI) allows for better definition of the relationships with the adjacent vascular and muscular structures. It can help to identify the lipomatous components, and it is useful for preoperative planning. However, the definitive diagnosis is provided by histopathological examination. Complete surgical excision is the first-line treatment, with a good prognosis in case of total eradication. We report the case of a 7-month-old male child with a rapidly growing mass that had typical radiological features of lipoblastoma.

Lipoblastoma: Diagnosis and surgical considerations

Lipoblastoma (LB) and lipoblastomatosis (LBS) are uncommon benign mesenchymal tumors of embryonal fat, occurring almost exclusively in infancy and early childhood. These fast-growing tumors have an excellent prognosis if properly treated. Eight consecutive children having pathologically demonstrated LB treated by the same surgical team were retrospectively reviewed. There were 5 boys and 3 girls between 7 to 36 months (median age 22 months). The localization of the tumors was on the thigh (1 case), abdomen (2 cases), axillary and pectoral region (1 case) paragluteal region (1 case), lumbar area (1 case), inguinal-scrotal (1 case), and in one case, presacral, gluteal and perirectal region (1 case). Five were focal and in 3 cases an infiltrative growth pattern was observed. One case exhibited a gross appearance resembling sacrococcygeal teratoma, with associated Dravet syndrome. No recurrence was noted in our series, after a mean follow-up of 28 months post operatory. Despite its rareness, LB must be kept in mind when diagnosing a rapidly growing fatty mass in children. Even when dealing with very large abdominal LB, complete surgical excision is possible, with an excellent prognosis. Due to the relatively high recurrence rate noted in the literature, particularly in LBS, follow-up is extremely important.

Cardiac lipoblastoma of the pulmonary valve: A rare tumor in an unusual location

BACKGROUD

Lipoblastoma is a rare, benign, fatty tissue tumour tumor that occurs in infancy and early childhood. Intrathoracic and mediastinal involvement of this tumour is rare, and an intracardiac location is even rarer.

AIMS

To report the first case of a lipoblastoma in the pulmonary valve.

MATERIALS

In this study, we report the case of a 15-month-old girl who presented with a tumour in the pulmonary valve.

RESULTS

The tumour was completely resected macroscopically. Histological examination of the lesion confirmed the diagnosis of lipoblastoma.

DISCUSSION

Most primary cardiac tumours are benign in the sense they are not invasive. However, benign tumours maintain the potential for serious illness related to significant haemodynamic compromise or life-threatening dysrhythmias. Due to the association of lipoblastoma with other heart malformations, preoperative diagnosis remains challenging.

CONCLUSION

Tumours on the heart valve are more likely to cause haemodynamic disturbances. Complete resection yields an excellent prognosis.

A large retroperitoneal lipoblastoma as an incidental finding: a case report

Background

Lipoblastoma is a rare benign mesenchymal neoplasm of infancy that most commonly occurs on the extremities and trunk but can arise at variable sites of the body. Retroperitoneal lipoblastomas are particularly rare but can grow to enormous size, and preoperative diagnosis is difficult with diverse, mostly malignant differential diagnoses that would lead to aggressive therapy. Since lipoblastoma is a benign tumor that has an excellent prognosis after resection, correct diagnosis is crucial.

Case presentation

A case of a large retroperitoneal tumor of a 24-month old infant that was clinically suspicious of a malignant tumor is presented. Due to proximity to the right kidney, clinically most probably a nephroblastoma or clear cell sarcoma of the kidney was suspected. Radiological findings were ambiguous. Therefore, the mass was biopsied, and histology revealed an adipocytic lesion. Although mostly composed of mature adipocytes, in view of the age of the patient, the differential diagnosis of a (maturing) lipoblastoma was raised, which was supported by molecular analysis demonstrating a HAS2-PLAG1 fusion. The tumor was completely resected, and further histopathological workup led to the final diagnosis of a 13 cm large retroperitoneal maturing lipoblastoma. The child recovered promptly from surgery and showed no evidence of recurrence so far.

Conclusion

Although rare, lipoblastoma should be included in the differential diagnoses of retroperitoneal tumors in infants and children, and molecular diagnostic approaches could be a helpful diagnostic adjunct in challenging cases.

Lipoblastoma: computed tomographic and magnetic resonance imaging features correlate with tumor behavior and pathology

BACKGROUND

Lipoblastoma is a rare benign neoplasm of immature fat cells in children. Imaging appearances are frequently complex, sometimes simulating liposarcoma.

OBJECTIVE

To characterize features of lipoblastoma on MRI and CT in comparison with recurrence risk.

MATERIALS AND METHODS

We identified cases via retrospective review of histopathology-proven lipoblastoma cases in a large referral database and a pediatric medical center. Two radiologists scored CT and MRI on the basis of lesion features.

RESULTS

We included a total of 56 children (32 boys and 24 girls) with a mean age of 2.6 years (range 0.1-13 years). Extremity lesions were most common (27%), followed by neck (19%), gluteal region (18%), chest (14%) and mesentery (14%). Children most commonly presented with painless masses (73%), followed by dyspnea (9%), distension (9%) and pain (7%). Non-adipose soft-tissue components were identified on CT and MRI in 78% of cases. Significant (moderate or marked) septations were noted in 59% and enhancement in 35%. Compartmental invasion was present in 43% of cases. Of paraspinal cases, 38% involved the neural foramina or central canal. Lesion complexity did not significantly correlate with age. Recurrence was observed in 9% of cases and was significantly correlated with compartmental invasion (correlation: 0.303, P=0.009) and septation complexity (correlation: 0.227, P=0.038) on initial imaging.

CONCLUSION

Although lipoblastoma is a fat-containing entity, many lesions demonstrate marked complexity and local infiltration that resemble liposarcoma, which is exceedingly rare in younger children. Compartmental invasion and thicker septations appear to confer greater risk of recurrence following resection.

Advances in the Diagnosis and Management of Neonatal Sarcomas

Neonatal sarcomas comprise a heterogeneous group of rare soft tissue neoplasms that present unique diagnostic and therapeutic challenges. Recent advances in molecular profiling have improved diagnostic capabilities and reveal novel therapeutic targets. Clinical trials demonstrate differences in behavior between sarcoma subtypes that allow for better clinical management. Surgical resection has been replaced with a multimodal approach that includes chemotherapy and radiotherapy. Despite these advances, neonates with sarcoma continue to fare worse than histologically similar sarcomas in older children, likely reflecting differences in tumor biology and the complexities of neonatal medicine. This review focuses on recent advances in managing neonatal sarcomas.

Lipoblastomas presenting in older children and adults: analysis of 22 cases with identification of novel PLAG1 fusion partners

Lipoblastomas are benign neoplasms of embryonal white fat that typically present in the first 3 years of life and show a lobular arrangement of maturing adipocytes with variable degrees of myxoid change. We systematically studied the clinicopathologic and genetic features of lipoblastomas arising in older children and adults. Cases with a diagnosis of lipoblastoma or maturing lipoblastoma in patients >3 years of age were retrieved from our archives. Immunostaining for CD34 and desmin and molecular studies (FISH, RNA sequencing) were performed. Twenty-two cases (8F; 14M) were identified in patients ranging from 4 to 44 years of age (median 10 years). Sites included extremity (n = 15), head and neck (n = 4), and trunk (n = 3) with tumor sizes varying from 1.6 to 17.5 cm (median 5). Only three tumors had histologic features of "conventional" lipoblastoma. The majority of tumors (n = 14) were composed of variably sized lobules of mature adipose tissue partitioned by thin fibrous septa ("maturing"). The remaining five cases consisted predominantly of bland spindled to plump ovoid cells embedded in a fibrous stroma, with a vaguely plexiform arrangement of small myxoid and adipocytic nodules ("fibroblastic"). CD34 was diffusely positive in all cases tested (21/21), while desmin immunoreactivity was identified in 12 of 21 cases (diffuse = 7, focal = 5). PLAG1 rearrangements were identified in 13 tumors in the entire cohort (59%), including all 5 fibroblastic tumors. RNA sequencing detected eight PLAG1 fusion partners, of which two were known (CHCHD7 and COL3A1) and six were novel (SRSF3, HNRNPC, PCMTD1, YWHAZ, CTDSP2, and PPP2R2A). Twelve cases had follow-up (1-107 months; median 21 months), and no recurrences were reported. Lipoblastomas may occur in older children and adults and may be difficult to recognize due to their predominantly adipocytic or fibrous appearance. Awareness that lipoblastomas may occur in older patients, careful evaluation for foci showing more typical morphologic features, ancillary immunohistochemistry for CD34 and desmin, and molecular genetic studies to identify PLAG1 rearrangements are the keys to recognizing these tumors.

Congenital tongue base lipoblastoma causing neonatal airway compromise

Lipoblastomas are benign tumours of immature fat cells presenting in infancy. A lipoblastoma within the airway lumen causing airway compromise is an extremely rare occurrence. We present a 6 hours of life girl who had airway compromise due to a lobulated mass at the base of the tongue. The mass was excised after emergency endotracheal intubation.

Benign mesenteric lipomatous tumor in a child: a case report and literature review

BACKGROUND

Lipomatous tumors are the most common type of soft-tissue tumors. Benign lipomatous tumors are lipomas and lipoblastoma. We herein report a case of benign mesenteric lipomatous tumor and the largest collection of known benign mesenteric lipomatous tumors in children in the literature.

CASE PRESENTATION

A 3-year-old girl presented with repeated dull abdominal pain and left abdominal mass swelling. On a physical examination, the child had a soft, moderately distended left abdomen that was not tender when palpated. Computed tomography and magnetic resonance imaging demonstrated a large fatty mass within the mesentery, measuring approximately 8 × 6 cm. The mass extended from the right upper quadrant to the lower pole of the kidneys. Laparotomy with resection of the mesenteric tumor was performed under general anesthesia. A well-capsuled tumor was a soft, yellow mass and found loosely attached to the mesenterium of the ileum. A histopathological examination demonstrated the lobular proliferation of mature adipocytes. Atypical lipoblasts were not seen. These features are compatible with benign lipomatous tumor, such as lipoma or lipoblastoma with maturation.

CONCLUSION

In conclusion, benign mesenteric lipomatous tumors tend to be large in size over 10 cm in longitudinal length. However, resection is well tolerated in the vast majority of cases with benign post-operative courses.

Primary paediatric chest wall tumours necessitating surgical management

INTRODUCTION

Limited literature exists on oncological chest wall reconstruction in the paediatric population, with the field still largely undecided on the best surgical reconstructive techniques to employ. The use of biological grafts/meshes is gaining popularity in certain adult surgical procedures but their use in paediatric procedures is rarely reported in the literature. We present the outcomes of our institution's multidisciplinary approach to managing paediatric chest wall tumours as well as our experience with the use of biological grafts for chest wall reconstruction following oncological resections.

METHODS

Data were analysed retrospectively from eight paediatric patients who were treated for primary chest wall tumours between 2010 and 2018.

RESULTS

The tumours comprised two lipoblastomas, three Ewing's sarcomas, an undifferentiated sarcoma with osteosarcomatous differentiation, a high grade undifferentiated sarcoma and a myofibroma. Seven of the eight patients underwent chest wall reconstruction with a biological graft. There were no postoperative mortalities and no evidence of recurrence in any of the patients in the series. No further chest wall operations were required and there were no postoperative infection related complications.

CONCLUSIONS

We support the use of biological grafts for chest wall reconstruction after oncological resections and maintain that a multidisciplinary approach is essential for the management of paediatric chest wall tumours.

Follow-up outcomes of pediatric patients who underwent surgical resection for lipoblastomas or lipoblastomatosis: a single-institution experience with a systematic review and meta-analysis

PURPOSE

The objective of this study was to examine the long-term outcomes of pediatric patients who underwent surgical resection for lipoblastoma and lipoblastomatosis (LB/LBM).

METHODS

A single-center retrospective study of pediatric patients with LB/LBMs seen between 1991 and 2015 was conducted. A systematic review, including studies published prior to late August 2018, was performed. Using a random effect meta-analysis, pooled weighted proportions and unadjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

The retrospective study included 16 patients, while the systematic review included 19 published studies consisting of 381 patients. Among 329 (82%) patients with follow-up information, the pooled recurrence rate was 16.8% (95% CI 10.9-23.5%; I² = 59%). The reported time to recurrence ranged from < 1 to 8 years. Recurrence risk was greater for incomplete (n = 34) than complete resection (n = 150): OR 11.4 (95% CI 3.0-43.6; I² = 43%). LBMs (n = 35) had a greater recurrence risk than LBs (n = 116): OR 5.5 (95% CI 1.9-15.9; I² = 0%). Recurrences were higher for studies with approximately ≥ 3 years of follow-up versus studies with < 3 years of follow-up.

CONCLUSION

Recurrences are more likely to occur with LBMs and/or incomplete resection. Follow-up beyond 3-5 years should be considered given that the recurrence risk appears to be greater in the long-term.

A Giant Childhood Mesenteric Lipoblastoma With Extensive Maturation

Abdominal lipoblastomas are uncommon soft tissue tumors in children and rarely arise from the mesentery. Due to intraabdominal location and slow growth, these masses can go unnoticed for long periods of time and often found on surgical exploration. We present a case of a 12-year-old male with years of abdominal distension accompanied by new onset early satiety that was found to have an intra-abdominal mass. He underwent an exploratory laparotomy revealing a large 33 x 27 x 15 cm rubbery mesenteric mass displacing the entire intra-abdominal contents, connected by a single vascular pedicle and encasing a loop of small intestine. The mass was resected and the patient did well without signs of recurrence. Histology confirmed the presence of mature adipocytes but on further cytogenetic analysis, a translocation between chromosomes 2 and 8 at the 12q arm was detected, which is often associated with lipoblastomas. This case represents the one of the largest mesenteric lipoblastomas that matured extensively to lipoma-like histology at the time of surgical resection.

Myxoid Lipoblastoma and Mimickers on Fine-Needle Biopsy in a Child

Image-guided percutaneous core needle biopsy is a standard and safe procedure for the diagnosis of both solid and hematological malignancies in children. Despite recent improvements, nondiagnosis biopsies persist. Lipoblastoma is a benign adipocytic tumor composed of embryonal fat admixed with mature adipocytes and occurring before the age of 1 year in one-third of cases. Lipoblastoma is usually easily diagnosed, but in some cases, diagnosis may be difficult on percutaneous biopsies, when the lipoblastic component is not well represented or when the tumor contains a prominent myxoid component mimicking other myxoid tumors. We report here a case of lipoblastoma with a predominant myxoid component and discuss differential diagnosis of myxoid lesions of infancy. In such cases, pathologic examination enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic studies, is needed to achieve accurate diagnosis, particularly on fine-needle biopsies.

Robotic resection of recurrent pediatric lipoblastoma

This case demonstrates successful resection of a rare, recurrent presacral-pelvic lipoblastoma in a 19-year-old female patient. Because of the anatomical location of the mass and its proximity to vital structures, the robotic approach allowed for both optimal visualization and effective debulking of the mass. Furthermore, with the use of an articulating laparoscopic camera, key visualization of the posterior lateral pelvis was possible. Using a wide breadth of technologies and resources is essential to broadening the surgical armamentarium and achieving resectability in otherwise challenging cases.

A large retroperitoneal lipoblastoma: A case report and literature review

INTRODUCTION

Lipoblastoma is a rare benign soft tissue tumor that occurs most commonly in infants and children. However, retroperitoneal lipoblastomas are rare, occurring in <5% of cases. We report a case of large retroperitoneal lipoblastoma and the largest collection of known retroperitoneal lipoblastomas in children in the literature.

CASE PRESENTATION

A 3-year-old girl presented with left abdominal mass. Magnetic resonance imaging (MRI) revealed a soft tissue mass measuring 12 × 8 × 6 cm in the retroperitoneal region. The mass had a clearly defined margin and a reticular pattern with an interposing fat component. Based on these findings, the mass was suspected to be a soft-tissue tumor, most likely lipoblastoma.Laparotomy with resection of the retroperitoneal mass was performed. The tumor was easily dissected from the retroperitoneal space without injury to surrounding structure.A histopathological examination demonstrated the mature proliferation of adipocytes and spindle-shaped cells separated by fibrovascular septa accompanied by myxoid changes. The cells were separated into lobules by septa, and areas of immature adipocytes showing a signet-ring or multivacuolar appearance were present at the periphery. Histopathological diagnosis was lipoblastoma. Follow-up at 6 months revealed no evidence of recurrence.

CONCLUSION

Retroperitoneal lipoblastoma is rare and tends to be large in size when diagnosed at presentation. Complete resection should not be delayed, as impingement on the surrounding structures is imminent.

Differential diagnosis of a large size tumor in the retroperitoneum: A case report of retroperitoneal lipoblastoma

Lipoblastoma can arise almost anywhere within the soft tissues, especially in the extremities. It is rarely seen retroperitoneally. A 3-year-old girl presented with a palpable abdominal mass underwent an exploratory laparotomy with resection of the retroperitoneal mass. Based on histopathologic and cytogenetic features, a final diagnosis of lipoblastoma was rendered. At 18-month follow-up, she had no evidence of recurrence.

Current management of lipoblastoma

Lipoblastoma is a rare and benign tumor arising from embryonal fat cells. It is generally diagnosed in children younger than 3 years of age and can occur in the extremities or on the trunk. We present our series of 10 children with lipoblastoma treated at Schneider Children's Medical Center of Israel between 2011 and 2016. Six boys and four girls underwent tumor resection at a median age of 2 years and 3 months (range 5 months to 5.6 years). Locations were trunk (6), groin (2), perineum (1), and omentum (1). Follow up ranges from 1 to 5 years. Two patients had a local recurrence and required a second resection 2 years (perineal) and 6 years (trunk) after the first surgery without further recurrence at 1.9 and 2.9 years, respectively.

CONCLUSION

Higher awareness of lipoblastoma enables optimal imaging strategies and resection. Long follow up is required due to local recurrences. The treatment of choice consists of complete, but non mutilating surgical resection. What is Known: • Lipoblastoma is a rare benign tumor of fatty tissue affecting children • Treatment consists of surgical resection What is New: • MRI is the modality of choice for follow up • Ten-year long-term follow up is required due to late recurrence.

A giant popliteal lipoblastoma in a 23-month-old girl: a case report

Background

Lipoblastomas are rare benign tumors that arise from embryonic white fat and almost always occur in babies and children. Here, we report a case of a giant popliteal lipoblastoma in a 23-month-old Japanese girl that was successfully treated via complete resection.

Case presentation

Our patient was a 23-month-old Japanese girl. At 6 months of age, she presented at a nearby hospital with a mass on the popliteal side of her lower right leg. She had no symptoms and was diagnosed as having a benign adipose tumor via magnetic resonance imaging. The mass gradually increased in size, and she was referred to our hospital at 1 year and 11 months of age. A physical examination and radiology revealed a localized mass 13 × 10 × 7 cm in size in the aforementioned area that restricted knee movement and caused proximal tibia deformity. Magnetic resonance imaging showed a giant circumscribed subcutaneous mass with multiple partitions that was hyperintense on T1-weighted and T2-weighted images but not fat-saturated on T2-weighted images. Based on these findings, she was diagnosed as having a lipoblastoma. Because the mass surrounded her popliteal artery and vein and part of the popliteal nerve, surgical resection was considered risky, and we opted to simply observe her. However, owing to rapid growth of the mass and the worsening of symptoms, she underwent complete resection at 2 years and 6 months of age. A histological examination confirmed the diagnosis of a lipoblastoma. She was discharged from our hospital 3 days after surgery with no symptoms. She could walk without pain at the 6-month follow-up, and no local recurrence was observed.

Conclusions

We successfully treated a giant popliteal lipoblastoma without complications by performing a total resection. Our report provides evidence that lipoblastomas should be considered for surgical resection when they progress or symptoms appear.

Analysis of clinical features of lipoblastoma in children

OBJECTIVE

A lipoblastoma is pathologically benign but often recurs. Due to its rarity, studies are scarce. The purpose of this study was to investigate the clinical characteristics of lipoblastoma occurring in children and to detect any correlations with the expression of Ki-67.

PARTICIPANTS

From 1998 to 2010, 33 patients were diagnosed with lipoblastoma at Seoul National University Children's Hospital.

METHODS

Ki-67 immunohistochemistry staining of the tumor tissue was performed.

RESULTS

A total of 33 patients (64% males) were enrolled in the study, with a mean age of 28 month. Eleven and 22 lesions were deep and superficial, respectively. Complete excisions were performed for 30 patients, and three underwent incomplete excisions. Two patients who underwent incomplete excision subsequently underwent a second operation due to tumor regrowth, and one patient had a recurrence despite complete excision. There was no statistically significant correlation observed between the tumor size or recurrence and the expression of Ki-67.

CONCLUSIONS

Lipoblastoma requires an accurate diagnosis and operative resection to alleviate the symptoms induced by its growth. Incompletely resected tumor may regrow; therefore, complete excision is the treatment of choice. Continuous follow-up is needed to monitor for recurrence of disease, even after a complete excision.

Varied Presentations of Pediatric Lipoblastoma: Case Series and Review of the Literature

Lipoblastoma is a rare neoplasm of embryonal adipose tissue most often encountered on the trunk and extremities of children. It commonly presents as a painless subcutaneous soft tissue mass, but there are other unique clinical presentations that are important to recognize. The differential is broad and includes sarcoma, vascular tumor, myofibroma, and other fibromatoses. We present three varied, distinct cases of pediatric lipoblastoma and review the literature on this condition.

Lipoblastoma of the Labia: A Case Report

BACKGROUND

Vulvar masses are rare in prepubertal girls. Lipoblastomas are benign adipose tumors that arise from embryonic white fat and occur almost exclusively in infants and children.

CASE

An 18-month-old female infant presented with a 2-cm mobile mass in the left labia majora. Imaging and examination revealed normal prepubertal gynecologic structures and a 4.5 cm fatty mass in the left labia. Surgical excision revealed a 3.8 cm well circumscribed adipose tissue mass consistent with maturing lipoblastoma on microscopic examination. Cytogenetic analysis revealed 79,XXX [7]/46,XX[13], a near-triploid clone.

SUMMARY AND CONCLUSION

The differential diagnosis of vulvar masses in children should include lipoblastoma. Although preoperative imaging has limited ability to differentiate lipomatous tumors, magnetic resonance imaging is the modality of choice for evaluating tumor extension and for surgical planning. Treatment is complete surgical excision with close follow-up for at least 5 years because of the high recurrence rate.

A Massive Intratumoral Aneurysmal Vessel in a Retroperitoneal Lipoblastoma

Lipoblastoma is a benign tumor and usually does not require radical operation for complete excision. We describe here a case of a retroperitoneal lipoblastoma with a massive intratumoral aneurysmal vessel.

[Retroperitoneal lipoblastoma in an infant. A case report]

INTRODUCTION

Lipoblastoma is a benign neoplasia of the adipose tissue. It is a rare conditionand almost exclusively presents in children under 3 years old. It usually occurs in extremities as a painless volume increase of progressive growth, with the definitive diagnosis being established by pathological and cytogenetic analysis. The treatment of choice is complete resection, and follow-up period of up to five years is recommended due to a recurrence of up to 25%.

OBJECTIVE

To present an unusual location of this uncommon condition in an infant, and review the related literature.

CASE REPORT

A sixteen-month child with an increase in abdominal growth of six-months progression, associated with a decreased food intake, and with no other symptoms. The imaging study revealed a lipoid-like image compromising almost the entire abdominal cavity, very suggestive of lipoblastoma. A resection was performed on an 18cm diameter retroperitoneal tumour that rejected the adjacent organs. Histological analysis was enough to confirm diagnosis without the need for cytogenetic analysis. The follow-up showed no recurrence of the disease.

CONCLUSION

Given the rarity of this disease and its unusual presentation, we communicate this clinical case, in order to be considered in the differential diagnosis of abdominal mass in chilhood.

Undifferentiated myxoid lipoblastoma with PLAG1-HAS2 fusion in an infant; morphologically mimicking primitive myxoid mesenchymal tumor of infancy (PMMTI)--diagnostic importance of cytogenetic and molecular testing and literature review

Lipoblastoma is a benign myxoid neoplasm arising in young children that typically demonstrates adipose differentiation. It is often morphologically indistinguishable from primitive myxoid mesenchymal tumor of infancy (PMMTI), which is characterized by a well-circumscribed myxoid mass with a proliferation of primitive mesenchymal cells with mild cytologic atypia. PMMTI occurs in the first year of life and is known to have locally aggressive behavior. No specific genetic rearrangements have been reported to date. In contrast, the presence of PLAG1 (Pleomorphic Adenoma Gene 1) rearrangement is diagnostic for lipoblastoma. We hereby demonstrate the combined application of multiple approaches to tackle the diagnostic challenges of a rapidly growing neck tumor in a 3-month-old female. An incisional tumor biopsy had features of an undifferentiated, myxoid mesenchymal neoplasm mimicking PMMTI. However, tumor cells showed diffuse nuclear expression by immunohistochemical (IHC) stain. Conventional cytogenetic and fluorescence in situ hybridization (FISH) analyses as well as next generation sequencing (NGS) demonstrated evidence of PLAG1 rearrangement, confirming the diagnosis of lipoblastoma. This experience warrants that undifferentiated myxoid lipoblastoma can mimic PMMTI, and the combination of cytogenetic and molecular approaches is essential to distinguish these two myxoid neoplasms. Literature on lipoblastomas with relevant molecular and cytogenetic findings is summarized. Our case is the first lipoblastoma diagnosed with a PLAG1 fusion defined by NGS technology.

Identification of COL3A1 and RAB2A as novel translocation partner genes of PLAG1 in lipoblastoma

Lipoblastoma is a rapidly growing, benign neoplasm in children. Surgical excision is usually curative, with a recurrence rate of about 20%. Because the histology of lipoblastoma is heterogeneous and overlaps with other lipomatous tumors, some lipoblastoma cases have been difficult to diagnose. The detection of PLAG1 gene rearrangement is useful for the diagnosis of lipoblastoma. Three fusion partner genes are known in relation to PLAG1 in lipoblastoma HAS2 at 8q24.1, COL1A2 at 7q22, and RAD51L1 at 14q24. Herein, we describe another two novel fusion genes in lipoblastoma tumor specimens. We checked six tumors for the presence of two known fusion genes, HAS2-PLAG1 and COL1A2-PLAG1. Only HAS2-PLAG1 was found in one of the cases. Next, we attempted to identify potential PLAG1 fusion partners using 5'RACE. Sequence analysis revealed two novel fusion genes, COL3A1-PLAG1 in three cases and RAB2A-PLAG1 in one case, respectively. As a result of the translocations, the constitutively active promoter of the partner gene drives the ectopic expression of PLAG1. We also evaluated whether a high level of PLAG1 expression can be used to help differentiate lipomatous tumors. PLAG1 expression was evaluated by real-time PCR in five lipoblastoma tumor specimens. The expressions were 70-150 times higher in lipoblastomas than in human adipocytes. However, PLAG1 expression was low in one case of lipoma. These results demonstrate that PLAG1 overexpression is a potential marker of lipoblastoma. Our findings, in agreement with previous studies, show that lipoblastoma is a group of lipomatous tumors with PLAG1 rearrangement and overexpression. © 2014 Wiley Periodicals, Inc.

Intrascrotal lipoblastoma: a report of two cases and a review of the literature

Lipoblastomas are rare benign mesenchymal tumors of fetal white fat tissue appearing most commonly in children under 3 years of age, and usually affecting the extremities. Only nine cases of intrascrotal lipoblastoma have been reported to our knowledge, and although they are benign, in one case an orchidectomy was performed. We describe two new cases of intrascrotal lipoblastoma, and review the literature.

The use of spinal angiography in the management of posterior mediastinal tumors: case series and review of the literature

INTRODUCTION

Resection of inferiorly located posterior mediastinal tumors can be complicated by their proximity to the artery of Adamkiewicz (AKA). Although uncommon, intraoperative injury to the AKA may result in paraparesis or paralysis secondary to spinal cord ischemia. The use of preoperative spinal angiography may serve as a useful adjunct to the surgeon in guiding extent of resection of the tumor to avoid injury to this critical artery.

METHODS

After IRB approval (H-31712), three patients, from 2008 to 2011, with lower posterior mediastinal tumors were identified. Their charts were reviewed for information concerning preoperative imaging, operative details, and postoperative neurologic complications. The literature regarding imaging of the AKA, cases of injury in pediatric patients, and recommendations for treatment after its injury were reviewed.

RESULTS

One patient, who did not have preoperative spinal angiography, developed transient paresis lasting 6 weeks after posterior mediastinal tumor resection. Two patients underwent preoperative spinal angiography with successful localization of the AKA. In both cases, the patients subsequently underwent posterior mediastinal tumor resection without injury to the artery and without postoperative neurologic sequelae.

CONCLUSIONS

Preoperative spinal angiography may serve as a useful adjunct in the evaluation of children with inferior posterior mediastinal tumors in order to delineate the relationship of the artery of Adamkiewicz to the tumor for the purpose of guiding surgical resection.

Mediastinal lipoblastoma: unexpected finding of a chest infection

A 2-year-old boy was presented with symptoms of chest infection. The chest radiograph showed a large mediastinal mass, which led to further investigations including biopsy of the tumour. Histopathological analysis revealed a diagnosis of lipoblastoma. We highlight the imaging appearance of the lesion. Although histopathological analysis is required for the confirmation of the diagnosis, cross-sectional imaging is useful in evaluating the extent of the tumour for surgical planning.

Cytogenetic analysis in the diagnosis and management of lipoblastomas: results from a single institution

BACKGROUND

Lipoblastomas are rare, benign, soft tissue tumors that occur primarily in young children. Treatment includes complete excision and surveillance for recurrence. Lipoblastomas can be indistinguishable from other benign lipomatous tumors and liposarcomas. Cytogenetic analysis can provide the definitive diagnosis in questionable cases, because benign and malignant lipomatous tumors exhibit specific nonrandom cytogenetic abnormalities. The purpose of the present study was to discuss the disease management and outcomes in a large contemporary group of patients with lipoblastoma.

MATERIALS AND METHODS

A retrospective chart review of patients diagnosed with lipoblastoma presenting from 2000-2011 was conducted. The data from these patients were compared with data from a previously published historical group of patients (1985-1999) from the same children's hospital.

RESULTS

We identified 37 patients in the contemporary cohort group and compared them with 25 patients from the historical group. The tumor involvement sites were similar. The current cohort group had a lower recurrence rate, although this might have been underestimated owing to a shorter follow-up period (median 1.4 y, range 2 wk to 11.0 y). Preoperative imaging findings led to an incorrect diagnosis in 62% of the patients. Cytogenetic analysis was used to help determine the final diagnosis in 50% of the cases. In 39% of cases, translocations involved the long arm of chromosome 8, the most common anomaly in lipoblastoma.

CONCLUSIONS

Lipoblastomas are rare tumors in young children that can be misclassified as other malignant or benign lipomatous tumors with markedly different outcomes and treatments. We recommend that cytogenetic analysis be routinely used for all pediatric lipomatous tumors to provide an accurate diagnosis and guide appropriate therapy and follow-up.

Mesenteric lipoblastoma presenting as a small intestinal volvulus in an infant: A case report and literature review

A 1-year-old boy with no underlying disorder presented with non-bilious vomiting since 4 days before admission. He was referred to our hospital and was diagnosed with a small bowel obstruction due to an intraabdominal tumor. Laparotomy revealed an intestinal volvulus with a soft and lobulated tumor arising from the mesentery. The resected tumor with a small part of the small bowel was diagnosed as lipoblastoma histologically. From a literature review, mesenteric lipoblastoma with an intestinal volvulus showed different characteristics such as greater frequency of vomiting and less frequency of abdominal mass as clinical symptoms, and the size of the tumor was smaller than that of the tumor without the intestinal volvulus.

A rare case of inguinolabial lipoblastoma in a 13-month-old female

Lipoblastoma is a rare, rapidly growing, benign mesenchymal tumor composed of various stages of maturing adipocytes that most often occurs in children under the age of 3. The common locations are the extremities and the trunk. Presentation in the genitoinguinal area is rare. We report a case of a 13-month-old female infant with a 4-month history of a progressively enlarging left labial mass that encompassed her left labium majora and inguinal region. Pelvic MRI confirmed growth from previous ultrasound size of 3 × 2 × 1 cm to 7 × 2 × 2 cm. Composition was suggestive of adipose tissue. The mass was excised through a left inguinal incision. The final pathology results described a lipoblastoma. Six year follow-up has not revealed any signs or symptoms of recurrence. Circumscribed lipoblastomas should be distinguished from their infiltrative counterpart, diffuse lipoblastoma or lipoblastomatosis, which can be more difficult to excise and thus, more likely to recur. Lipoblastoma should also be distinguished from myxoid liposarcoma, which has malignant features, carries a high risk of recurrence, and requires a more aggressive management protocol. Although rare, lipoblastoma should be considered as part of the differential diagnosis of a rapidly growing vulvar mass in prepubertal children.

Retroperitoneal lipoblastoma: a discussion of current management

Retroperitoneal lipoblastomas are rare tumors found in young pediatric patients. Despite their large size at presentation, complete resection is usually achieved with minimal complications. Diagnosis is typically made after pathologic examination of the operative specimen, and cytogenetic analysis may be a key component in differentiating lipoblastoma from other lipomatous tumors. We present one such case of a large, retroperitoneal lipoblastoma and discuss the management of this uncommon entity.

A novel t(3;8)(p13;q21.1) translocation in a case of lipoblastoma

Lipoblastoma is a rare benign neoplasm of embryonic white fatty tissue primarily found in the extremities of children <3 years old (Batanian et al., Cancer Genet Cytogenet 125(1):10-13, 2001; McVay MR et al., J Pediatr Surg 41(6):1067-1071, 2006; Kamal et al., J Pediatr Surg 46(7):E9-E12, 2011). Translocations affecting the 8q11-13 region are commonly reported with lipoblastoma and proper diagnosis requires cytogenetic analysis to distinguish it from malignant myxoid liposarcoma (Miller et al., J Pediatr Surg 32(12):1771-1772, 1997; Morerio et al., Pediatr Blood Cancer 52(1):132-134, 2009). We describe an additional case of lipoblastoma containing a new translocation t(3;8)(p13;q21.1), which has not previously been reported in a healthy asymptomatic child.

Acute respiratory distress caused by a giant mediastinal lipoblastoma in a 16-month-old boy

Lipoblastoma is a rare benign tumor arising from embryonic fat; it occurs mainly in the extremities and almost exclusively in infants and children younger than 3 years. We present a case of giant mediastinal lipoblastoma in a 16-month-old boy who presented with acute respiratory distress. The mass was completely excised through a left posterolateral thoracotomy. The postoperative course was uneventful, and the pathologic final diagnosis was lipoblastoma. Although extremely rare, mediastinal lipoblastoma can be life threatening; therefore, it should be included in the differential diagnosis of mediastinal mass in younger subjects.