Radiological-pathological correlation in lipoblastoma and lipoblastomatosis

Intrathoracic extension of a chest wall Lipoblastoma in an infant: A rare case report

We report the case of a 9-month-old female infant who presented with a history of enlarging chest wall mass secondary to a lipoblastoma with intrathoracic extension. The baby was successfully treated with a surgical resection. Chest wall lipoblastomas with intrathoracic extension are quite uncommon, with few reports available to date.

Radiologic and Clinical Features of Infantile Hemangioma: Potential Pitfalls and Differential Diagnosis

Infantile hemangioma (IH) is the most common neoplasm in children, but it may mimic other types of vascular anomalies or nonvascular benign and malignant tumors. In most cases, the clinical appearance, time of onset, and pattern of involution facilitate its diagnosis. Imaging evaluation is not always needed since the IH features at clinical presentation are usually characteristic, but when needed, US and frequently MRI are the imaging modalities of choice. Clinical photography or photographic documentation plays a central role in monitoring these lesions over their clinical course. Photographic documentation can also add confidence and alert the radiologist when interpreting imaging studies. Some vascular anomalies, especially vascular malformations, are a frequent source of confusion, as these may resemble IHs clinically and at imaging. The lack of uniform terminology also hinders an accurate diagnosis. To unify the terminology and minimize confusion, the International Society for the Study of Vascular Anomalies created a helpful classification in 1994. In addition, radiologists need to be aware of and become familiar with other neoplasms in children that may resemble IH to avoid misdiagnosis and unnecessary procedures. Fibrous and lipomatous tumors are examples of benign tumors that can mimic IHs clinically and at imaging, whereas rhabdomyosarcoma, infantile fibrosarcoma, neuroblastoma, and lymphoproliferative disorders are examples of malignant neoplasms. The authors review the features of IH at clinical presentation and imaging evaluation, highlighting its different phases of evolution and stressing the importance of photographic documentation. The authors also review pitfalls of IH with helpful pearls for differentiation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Khanna and Briones in this issue.

Mesenteric lipoblastomatosis: an uncommon fat-containing childhood tumour diagnosed on imaging

Lipoblastomatosis of mesentery is an extremely rare benign fat-containing mesenchymal tumour in infants and young children. On imaging, it appears as a solid infiltrating mass interspersed with macroscopic fat. We describe the distinctive imaging features of a large mesenteric Lipoblastomatosis, corroborated with intraoperative and histopathological features. We hope the case report and short review about this rare entity will increase the diagnostic confidence of reading radiologists while formulating differentials for lesions of similar appearance in the paediatric age group.

Lipoblastoma of scalp in a 4-month-old patient: an extremely rare case report and review of the literature

Lipoblastoma is a rare benign tumor originating from adipose tissue, usually seen in infancy and early childhood. Here, we present a case of scalp lipoblastoma in a 4-month-old that we treated surgically and review the literature. Although lipoblastomas may be seen in various locations during infancy and early childhood, rarely, they can also develop in the scalp.

Imaging features of Lipoblastoma

Lipoblastoma is a rare benign soft tissue tumor found in infants and young children. It presents as an enlarging mass commonly observed in extremities, trunk, head and neck regions. Imaging features include a hyper-echoic mass on ultrasound, heterogonous fat density lesion on CT scan with enhancing septations and no calcification, and high T1 signal mass that drops the signal intensity on fat suppression MRI images. Total excision of such lesion is the treatment of choice, and follow-up is recommended to rule out recurrence.

Paediatric thoracic wall lipoblastoma in a 7-year old: a rare tumour of childhood

Lipoblastoma is a rare benign mesenchymal tumour derived from embryonic white fat tissue. Lipoblastoma generally occurs in children less than 3 years of age, and fewer than 200 cases have been reported in the English literature. There are hardly a dozen reports describing intrathoracic and thoracic involvement. We report a case of a 7-year-old boy who presented with a slowly growing right thoracic wall mass for a duration of 1 year. Radiological investigations (ultrasonography and contrast-enhanced CT of the chest showed the presence of a fat-containing, low density extrapulmonary soft tissue mass) could not confirm the diagnosis, and repeat biopsies also were not conclusive. The mass was excised and histopathology confirmed it as lipoblastoma. A review of literature pertaining to the clinical presentation, radiological features and histopathology of this rare condition has been discussed.

Fat-containing pelvic lesions in females

Pelvic tumors are common in females and have a broad differential diagnosis. The clinical management of pelvic tumors varies widely-from observation to surgical resection-and imaging plays a pivotal role in diagnosis and clinical decision-making in these cases. In particular, imaging can help determine the organ of origin and tissue content of these tumors, which are the most important steps to narrowing the differential diagnosis. Fat has a characteristic appearance and is often easily identified on ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). The amount and distribution of intralesional fat varies in different types of tumors. Macroscopic intralesional fat is often easily recognized by its hyperechoic appearance on US and low attenuation on CT similar to subcutaneous fat. On MRI, macroscopic fat is hyperintense on T1-weighted (T1W) images, with characteristic signal loss on fat-saturated sequences and India-ink artifact on opposed-phase T1W images. Macroscopic fat is the hallmark of teratomas, which are the most common ovarian neoplasms. Uterine lipoleiomyomas, peritoneal loose bodies, intraperitoneal and extraperitoneal primary lipomatous tumors such as lipoma and liposarcomas, and extra-adrenal myelolipomas are other pelvic masses distinguished by the presence of macroscopic fat. However, the imaging diagnosis of pelvic masses containing minimal or microscopic fat, such as immature ovarian teratomas, steroid cell ovarian neoplasms, and extramedullary hematopoiesis, can present a diagnostic challenge owing to their nonspecific appearance on US or CT. Obtaining MRI with in-phase and opposed-phase dual-echo T1W sequences and depicting chemical shift artifacts can be helpful in distinguishing these lesions.

Scrotal Lipoblastoma with Radiological and Histological Correlation

Lipoblastomas are rare benign mesenchymal tumors comprised primarily mature adipocytes, which are most commonly found in infants and children younger than 3 years. They are usually found in the extremities, trunk, head, neck, and retroperitoneum, although cases occurring in the scrotum have been reported. Due to its rarity, there is a relative paucity of literature describing its imaging and management. We present a rare case of a scrotal lipoblastoma, and discuss the current imaging strategies to differentiate this adipocytic tumor from other more common paratesticular masses, including aggressive neoplasms such as rhabdomyosarcomas. Knowledge of the radiological appearance of lipoblastoma can provide the correct diagnosis and prevent unnecessary orchiectomy.

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.

Imaging of Pediatric Soft Tissue Tumors and Tumor-like Conditions

Lumps and bumps are frequently seen in children, and the vast majority are a result of trauma, infection, or inflammation. True soft tissue neoplastic lesions are rare; however, their wide and complex classifications make these lesions challenging to manage. Imaging features are usually nonspecific, and a reasonable list of differential diagnoses can be generated following consideration of the clinical presentation, age, and anatomical location of the lesion. In this article, we offer a practical approach to diagnosing such lesions by discussing the most common three benign and malignant lesions in different anatomical regions stratified by age with emphasis on certain features that might aid in the diagnosis such as depth, multiplicity, calcification, or other specific imaging feature.

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.

A Rare Case of Giant Mesenteric Lipoblastoma in a 6-Year-Old Child and Review of the Literature

Giant mesenteric lipoblastoma is a rare benign tumor arising from the adipocytes. It can mimic malignant tumors, and its diagnosis is difficult before surgery. Imaging studies could lead the diagnosis but not confirm it. Those tumors arising in the abdomen are usually larger and can cause symptoms of compression. Surgical excision is the treatment of choice, and a long-term follow-up is necessary to detect local recurrences. Only a few cases of lipoblastomas arising from the mesentery are reported in literature. We present a case of a rare giant lipoblastoma arising from the mesentery of a 6-year-old girl, with a history of postprandial abdominal pain.

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.

Up-to-date imaging review of paediatric soft tissue vascular masses, focusing on sonography

The purpose of this article is to provide an up-to-date overview on imaging of paediatric vascular soft tissue masses, including both neoplastic and non-neoplastic lesions. We describe the-often challenging-imaging diagnosis-mainly performed by ultrasound (and secondarily by MRI) and differential diagnosis of vascular soft tissue lesions in children. We underline how important it is to determine whether a vascular anomaly has a regional vascular origin, or if there are other entities, ranging from benign to malignant lesions, which have flow-signal or blood degradation products. Even though clinical examination and patient's history are the first and indispensable steps in the initial diagnosis, the role of imaging is crucial, not only to determine whether a mass represents a true tumour/pseudo-tumour, but also to achieve a more correct diagnosis and determine the extension of the tumour/pseudo-tumour and its relation with the nearby anatomic structures.

Chest wall lipoblastoma in a 3 year-old boy

Background

Lipoblastoma is a rare, benign, fatty tissue tumor that occurs in infancy and early childhood. The most common tumor locations are the extremities and the torso. The location of this tumor in the chest wall and an intrathoracic extension is uncommon.

Case report

We present a case of a 3-year-old boy with anterior chest wall lipoblastoma with an intrathoracic extension. Computed tomography was suggestive of lipoblastoma. The mass was completely excised through a right posterolateral thoracotomy. The histologic examination of the lesion confirmed the diagnosis of lipoblastoma.

Conclusion

Although extremely rare, chest wall lipoblastoma should be included in the differential diagnosis of thoracic mass in childhood.

A Case of Orbital Lipoblastoma: Temporal Evolution of Imaging Findings

Lipoblastoma is a rare tumor that is not commonly seen in the orbit. The authors present clinical features, histopathologic findings, changes in the radiologic findings over time, and the radiological-pathological correlation of orbital lipoblastoma in an infant. A 3-month-old male infant presented with a palpable mass on the left upper eyelid. The patient was observed for 1 year with magnetic resonance imaging. At the age of 15 months, the patient underwent excisional biopsy. Histopathologic examination showed features of hypocellular lobules with a mixture of adipocytes of various stages of maturity and myxoid stroma separated by prominent fibrous septa, confirming a diagnosis of orbital lipoblastoma. [J Pediatr Ophthalmol Strabismus. 2017;54:e67-e70.].

Up-To-Date Practical Imaging Evaluation of Neonatal Soft-Tissue Tumors: What Radiologists Need to Know

OBJECTIVE

The purposes of this article are to provide an up-to-date overview of neonatal soft-tissue tumors, including information regarding their unique nature, and to present practical imaging techniques and characteristic imaging findings.

CONCLUSION

Neonatal soft-tissue tumors are a unique set of neoplasms that often have characteristic clinical and imaging findings. Imaging evaluation, mainly with ultrasound and MRI, plays an important role in the initial diagnosis, staging, preoperative assessment, and follow-up evaluation. Clear understanding of practical imaging techniques combined with up-to-date knowledge of characteristic imaging findings can help the radiologist provide a timely and accurate diagnosis of these neoplasms and can lead to optimal neonatal patient care.

Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing

Fat-containing tumors are the most common soft-tissue tumors encountered clinically. The vast majority of fat-containing soft-tissue masses are benign. Lipomas are the most common benign fat-containing masses and demonstrate a characteristic appearance at magnetic resonance (MR) imaging. Less common benign soft-tissue masses include lipoblastoma, angiolipoma, spindle cell lipoma/pleomorphic lipoma, myolipoma, chondroid lipoma, lipomatosis of nerve, lipomatosis, hibernoma, and fat necrosis. Well-differentiated liposarcomas (WDLPSs)/atypical lipomatous tumors (ALTs) are locally aggressive soft-tissue masses that do not metastasize. Biologically more aggressive liposarcomas include myxoid, pleomorphic, and dedifferentiated liposarcomas. At MR imaging, lipomas typically resemble subcutaneous fat but may contain a few thin septa. The presence of thick, irregular, enhancing septa and nonfatty soft-tissue mass components suggests liposarcoma rather than lipoma. However, benign lipomatous lesions and WDLPS/ALT often have overlapping MR imaging findings. Distinguishing WDLPS/ALT from a benign lipomatous lesion or from fat necrosis at imaging can be challenging and often requires histologic evaluation. We present the spectrum of fat-containing masses, using the World Health Organization classification of adipocytic tumors, with an emphasis on commonly encountered lesions, characteristic MR imaging findings associated with specific tumors, and overlapping MR imaging findings of certain tumors that may require histologic sampling. We also briefly discuss the role of molecular markers in proper characterization and classification of fat-containing soft-tissue masses. (©)RSNA, 2016.

Fat-containing soft-tissue masses in children

The diagnosis of soft-tissue masses in children can be difficult because of the frequently nonspecific clinical and imaging characteristics of these lesions. However key findings on imaging can aid in diagnosis. The identification of macroscopic fat within a soft-tissue mass narrows the differential diagnosis considerably and suggests a high likelihood of a benign etiology in children. Fat can be difficult to detect with sonography because of the variable appearance of fat using this modality. Fat is easier to recognize using MRI, particularly with the aid of fat-suppression techniques. Although a large portion of fat-containing masses in children are adipocytic tumors, a variety of other tumors and mass-like conditions that contain fat should be considered by the radiologist confronted with a fat-containing mass in a child. In this article we review the sonographic and MRI findings in the most relevant fat-containing soft-tissue masses in the pediatric age group, including adipocytic tumors (lipoma, angiolipoma, lipomatosis, lipoblastoma, lipomatosis of nerve, and liposarcoma); fibroblastic/myofibroblastic tumors (fibrous hamartoma of infancy and lipofibromatosis); vascular anomalies (involuting hemangioma, intramuscular capillary hemangioma, phosphate and tensin homologue (PTEN) hamartoma of soft tissue, fibro-adipose vascular anomaly), and other miscellaneous entities, such as fat necrosis and epigastric hernia.

Intra-abdominal fat. Part III. Neoplasms lesions of the adipose tissue

This article focuses on various cancerous lesions that are found beyond organs in the intra-abdominal fat and can be visualized with ultrasonography. These lesions are divided into five groups. The first group includes primary benign tumors containing adipocytes, such as lipoma, lipoblastoma, hibernoma and other lesions with an adipose tissue component, such as myolipoma, angiomyolipoma, myelolipoma and teratoma. The second group comprises primary malignant adipocytecontaining tumors, including liposarcoma and immature teratoma. The third group contains primary benign tumors without an adipocyte component that are located in intra-abdominal fat. This is a numerous group of lesions represented by cystic and solid tumors. The fourth group encompasses primary malignant tumors without an adipocyte component that are located in intra-abdominal fat. These are rare lesions associated mainly with sarcomas: fibrosarcoma, malignant fibrous histiocytoma, hemangiopericytoma and leiomyosarcoma. An epithelioid tumor at this site is mesothelioma. The last but not least group includes secondary malignant tumors without an adipocyte component located in intra-abdominal fat. This is the most numerous group with prevailing carcinoma foci. For each of these groups, the authors present ultrasound features of individual lesions and discuss their differential diagnosis. In the vast majority of cases, the material for cytological and histological analysis can be obtained during ultrasound-guided procedures. This is the advantage of this imaging modality.

Successful laparoscopic extirpation of a large omental lipoblastoma in a child

Omental lipoblastoma is extremely rare among benign tumors. We herein report the case of a child who underwent laparoscopic extirpation of a large omental lipoblastoma. A 4-year-old girl was diagnosed with an intra-abdominal solid tumor. Abdominal imaging revealed a fat density mass that was well encapsulated and measured 18 × 15 × 7.5 cm in size. Considering the MRI findings and movability of the tumor, we strongly suspected that the lesion was an omental lipoblastoma. We initially decided to perform laparoscopic exploration and, if possible, extirpation of the solid tumor sequentially. A total of five trocars were used, and the tumor was found to originate from the omentum. We successfully performed complete resection of the tumor laparoscopically. A histological examination revealed lipoblastoma. For large abdominal tumors in children, the laparoscopic approach is recommended as the first procedure when the tumor is preoperatively considered to be benign and resectable.

Mesenchymal tumours of the mediastinum--part I

The mediastinum is an anatomically defined space in which organs and major blood vessels reside with surrounding soft tissue elements. The thymus is an important organ in the mediastinum, and many of the masses encountered in the mediastinum are related to this organ. Most neoplasms diagnosed in the mediastinum are epithelial tumours (thymomas and thymic carcinomas), lymphomas or germ cell tumours. In contrast, soft tissue tumours of the mediastinum are rare. In 1963, Pachter and Lattes systematically reviewed soft tissue pathology of the mediastinum, covering the hitherto described [2, 226, 227] In this review, based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart, we provide an updated overview of mesenchymal tumours that may be encountered in the mediastinum.

A case of unusual histology of infantile lipoblastoma confirmed by PLAG1 rearrangement

Lipoblastoma, a relatively rare benign adipose neoplasm, predominantly affects children younger than 3 years of age. We herein report the case of a 7-month-old girl with an unusual myxomatous histology of lipoblastoma. A rapidly growing mass was detected in the subcutaneous area of the left buttock. Histologically, the tumor consisted of abundant myxoid stroma exhibiting cellular atypia and a high mitotic activity. Although the histological findings were unusual, the tumor was diagnosed as a lipoblastoma according to both PLAG1 immunohistochemistry and the presence of PLAG1 rearrangement on fluorescence in situ hybridization.

Torsion of a giant mesocolic lipoma in a child with Bannayan-Riley-Ruvalcaba syndrome

A 6-year-old boy with Bannayan-Riley-Ruvalcaba syndrome (BRRS) presented to the emergency department with periumbilical abdominal pain for 12 h. A contrast-enhanced abdominal and pelvis CT examination revealed significant interval change in the size and appearance of a previously seen hypoattenuating right mesocolic fatty mass suggestive for lipoma, first observed 5 months prior. This lesion demonstrated new enhancing internal septations, a thickened capsule, interval development of adjacent mesenteric fat stranding and engorgement of the mesenteric vessels. Given the short follow-up interval and acute clinical presentation, imaging findings were suggestive for torsion. We present this case for the unusual imaging findings as well as to highlight the differential diagnosis for abdominal fat containing lesions by imaging in patients with BRRS and other hamartomatous syndromes.

Imaging of the inguinal canal in children

The inguinal canal is often seen at the edge of the field of view on plain radiography, computed tomography, or magnetic resonance imaging and may often not be scanned when performing sonography of the scrotum or abdomen. As a result, pathology in this anatomical region may be easily overlooked. The peculiar embryology of the inguinal canal makes the identification of pathology in the inguinal region significant, as some of the processes that take place within the scrotum may originate in the abdomen, and vice versa. This article reviews the relevant embryology of the inguinal canal, discusses abdominal and scrotal conditions that involve the inguinal region, and illustrates associated pathology.

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.

Ultrasound evaluation of superficial lumps and bumps of the extremities in children: a 5-year retrospective review

Ultrasonography is commonly requested for evaluation of palpable soft-tissue masses of the extremities in children. Although malignancy is quite rare in these children, it remains a primary diagnostic concern. As a result, knowledge of the common and uncommon soft-tissue lesions as well as sonographic techniques for optimized evaluation are crucial for accurate assessment. This review describe the sonographic imaging appearance of the most commonly encountered superficial soft-tissue lesions at a tertiary academic pediatric hospital. Features of malignancy and findings warranting further evaluation such as lesion size, heterogeneity, vascularity and depth of involvement are also discussed.

Paediatric lipoblastoma in the head and neck: three cases and review of literature

Lipoblastoma is a rare benign tumour arising from embryonic white fat. The tumours occur primarily in infancy and early childhood and usually arise from the limbs and the trunk, but neck involvement is rare. We report three cases of head and neck lipoblastoma. In all cases, imaging showed a well-delineated, fat-containing tumour. After surgical resection, the outcome of these patients was uneventful.

Giant abdomino-pelvic adipose tumors of childhood

Adipose tumors are rare in pediatric age and are commonly represented by benign forms: lipoma and lipoblastoma/lipoblastomatosis. Generally localized in subcutaneous tissue of the trunk and extremities, they can exceptionally occur as giant intra-peritoneal or pelvic masses. These tumors could reach considerable size prior to diagnosis since they are asymptomatic. The authors report a case series of three giant abdomino-pelvic adipose tumors.

CT characteristics of primary retroperitoneal neoplasms in children

Primary retroperitoneal neoplasms are uncommon in children. Retroperitoneal neoplasms are either mesodermal, neurogenic, germ cell ectodermal or lymphatic in origin. In general, primary retroperitoneal neoplasms in children have different spectrum and prevalence compared to those in adults. Neuroblastoma, rhabdomyosarcoma, benign teratoma and lymphoma are the common retroperitoneal neoplasms. In this review, the clinical and CT futures of common retroperitoneal neoplasms in children are described. Coarse, amorphous, and mottled calcification are very common in neuroblastoma. Paraganglioma tends to show marked and early enhancement and may present with clinical symptoms associated with the excess catecholamine. Sarcomas are often very large and have heterogeneous appearance. Imaging cannot be reliably used to identify the type of retroperitoneal sarcomas due to overlapped radiographic features. In children, lipoblastoma is the most common lipomatous tumor in the retroperitoneum. The percentage of visible fat in tumor varies depending on the cellular composition of the lesion. The CT characteristics of teratoma are quite variable, which may be cystic, solid, on a combination of both. Typically teratoma appears as a large complex mass containing fluid, fat, fat-fluid level, and calcifications. Lymphoma is often homogeneous on both enhanced and unenhanced CT scans. Necrosis and calcification are rare on CT. In conclusion, making a final histological diagnosis of retroperitoneal tumor base on CT features is not often possible; however, CT can help to develop a differential diagnosis and determine the size and extent of the retroperitoneal neoplasms.

Giant omental lipoma in a 13-year-old adolescent girl

Although lipoma is a common benign mesenchymal tumor, its occurrence in the omentum is a rare finding. We report an unusual case of omental lipoma in a 13-year-old adolescent girl. The mass was completely excised and weighed 12.3 kg. The patient is alive and well with no evidence of recurrence at 4 months of follow-up.

Mediastinal lipoblastomatosis: report of a case with complex karyotype and review of the literature

Lipoblastoma or lipoblastomatosis is an uncommon fatty tumor seen in children up to the age of 5 years, with very rare exceptions above that age. It usually occurs in the extremities, but it can arise in other anatomical sites, including the head and neck area, trunk, mediastinum, mesentry, and retroperitoneum. We report a 9-month-old boy with mediastinal lipoblastomatosis showing unusually complex chromosomal aberrations. Five years following surgical excision that was incomplete as a result of the tumor's proximity to major blood vessels, the patient developed a recurrence of the tumor in the mediastinum with extension to the neck and spinal dura. We present a review of the literature related to mediastinal lipoblastoma and lipoblastomatosis and the chromosomal abnormalities of these tumors.

Mediastinal lipoblastoma causing diaphragmatic eventration: a case report and review of the literature

Lipoblastomatous tumors are quite rare neoplasms derived from embryonic white fatty tissues. The majority is seen in infancy and early childhood. Generally they arise in extremities. Here, we present a 12-month-old female infant presenting with a mediastinal and cervical mass, showing left diaphragmatic eventration. We reviewed these cases and discussed clinical manifestations, radiologic, and histopathologic findings and treatment of these tumors.