Lipoblastoma and lipoblastomatosis in infancy and childhood: histopathologic, ultrastructural, and cytogenetic features

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.

Submandibular lipoblastoma: Case report of a rare tumor in childhood

Lipoblastoma is a rare, benign tumor usually occurring in childhood. It is essentially localized in the extremities and trunk, with few cases reported in the neck. We report the case of a 2-year-old girl with a rapidly enlarging, painless neck mass. Magnetic resonance imaging (MRI) revealed a 3-cm mass in the right submandibular region. Review of literature, diagnostic methods, and genetics of lipomatous tumors are discussed. Complete surgical excision via a lateral cervical approach demonstrated a white soft tissue with an adherent ganglion. Histology and immunohistochemistry confirmed the diagnosis of lipoblastoma. Cervical lipoblastoma is rare, and typically asymptomatic, rarely causing nerve compression or airway obstruction. MRI can help identifying the lipomatous nature of the mass, but the findings can be inconsistent due to variable maturity of fat cells and the mesenchymal content of the tumor. Diagnosis is always based on pathological examination. Further chromosomal analysis is useful in differentiating lipoblastoma from liposarcoma. Complete surgical excision is the recommended treatment.

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.

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.

A Cheek Mass in a 5-Year-Old Child

OBJECTIVES

To describe the management of a 5-year old female with a painless, mobile cheek mass.

METHODS

A retrospective chart review of presentation, imaging, pathology and management.

RESULTS

Magnetic resonance imaging showed a heterogenous mass with solid and lipomatous components. The mass was a lipoblastoma on histopathology and was excised completely with no evidence of recurrence.

CONCLUSIONS

The diagnosis and management of a cheek mass in a child is challenging. Imaging is important but not diagnostic. Surgical excision is the primary management of a lipoblastoma.

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.

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.

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.

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.

[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.

Huge Mediastinal Lipoblastoma in a Nine Year-old Boy Successfully Removed Surgically

A nine year-old boy presented with symptoms of dyspnoea. The chest radiograph and computed tomography scan revealed a large mediastinal tumour. A decision to operate on the patient was made. A huge 2.45 kg mediastinal lipoblastoma was successfully removed from the boy's chest. At three years no evidence of recurrence was found.

Recurrent lipoblastoma of upper extremity in a 9-year-old boy

Lipoblastoma is a benign soft-tissue tumour of infancy and early childhood. The location of the tumour varies from that of the extremities, trunk, retroperitoneum, mediastinal, inguinal and scrotal regions. The most common symptoms are painless mass with or without increasing size. Complete surgical excision is the gold standard for managing this entity. Though rare, the recurrence occurs usually because of incomplete excision. We report a case of recurrent lipoblastoma of the upper extremity in a 9-year-old boy.

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.

Desmin-positivity in spindle cells: under-recognized immunophenotype of lipoblastoma

Lipoblastoma is a distinct benign fatty tumor composed of adipocytes, lipoblasts, and primitive mesenchymal cells with a myxoid stroma. Lipoblastoma harbors characteristic fusion genes involving the PLAG1, resulting in aberrant expression of PLAG1. However, the nature of the primitive mesenchymal cells remains obscure. In our routine pathology practice, we noticed desmin-positive spindle mesenchymal cells in lipoblastomas, which is a hitherto poorly described phenomenon. Thus, we examined the expression of several myogenic markers including desmin in a variety of 95 mesenchymal tumors with fatty elements. Fourteen of the 15 lipoblastomas examined contained desmin-positive spindle cells, which also showed nuclear expression of PLAG1, whereas α-smooth muscle actin, muscle specific actin, h-caldesmon, and myogenin were negative. Some spindle cells in subsets of atypical lipomatous tumors/well differentiated liposarcomas (6/20), dedifferentiated liposarcomas (11/31) and pleomorphic liposarcomas (2/10) were positive for actins and/or desmin, supporting focal myofibroblastic or smooth muscle differentiation. The other tumors, including 11 myxoid/round cell liposarcomas, four spindle cell lipomas, and four lipofibromatoses, were negative for all of the myogenic markers assessed. The almost consistent desmin expression in spindle mesenchymal cells suggests a potential diagnostic utility of this marker and myofibroblastic phenotype of fractions in lipoblastoma cells.

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.

Intrascrotal lipoblastoma in a ten year old: case report and review of literature

Lipoblastoma is a rare benign soft tissue tumor encountered almost exclusively in infancy and early childhood. The location of tumors varies, but most occur in the extremities, trunk, head and neck. Less frequently, lipoblastomas have been reported in the mediastinum, the retroperitoneum and the inguinal region. Only 7 cases of lipoblastoma in the scrotum have been reported so far in the English literature, with none of the patients older than 8. We report an intrascrotal lipoblastoma in a 10 year-old boy. The differential diagnosis is discussed with reference to the literature.

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.

Adipose and myxoid tumors of childhood and adolescence

Adipose and myxoid tumors in children are an unusual and challenging group of neoplasms that have some unique aspects in contrast to these tumors in adults. Less than 10% of soft tissue neoplasms in the 1st 2 decades of life have an adipose phenotype and most are benign. The most common are various types of lipoma and lipoblastoma. Liposarcoma in young patients is rare and has a distinctive distribution of histologic subtypes, including classic myxoid liposarcoma, and unusual variants, such as pleomorphic-myxoid liposarcoma. Pathologic examination enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic studies, is useful for classification of difficult cases. Myxoid tumors can overlap with adipose tumors and are included in this review because of the morphologic similarities and importance of diagnostic accuracy. This article reviews the clinicopathologic features of adipose and myxoid tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents and the differential diagnosis.

Plantar angiomyxolipoma in a child

Angiomyxolipoma, a lipoma variant with myxoid areas and vascular proliferation was originally described in 1996 and till date has only 12 cases in published literature. Only two cases have been reported in children involving buccal mucosa and knee, respectively. The authors report a case of angiomyxolipoma, on the plantar surface of the left foot, in a 4-year-old male child who presented to our institution in Abha city (Kingdom of Saudi Arabia). The significant differential diagnosis of this neoplasm from other similar lipomatous tumours occurring in adult and paediatric population is discussed. The importance of recognising these tumours lies in their recognition as separate entity and the present case may add to the knowledge, clinical behaviour and prognosis of these less reported lipomatous neoplasms.

Lipoblastoma with unique localization requiring tracheal and esophageal resection

Lipoblastoma and lipoblastomatosis are rare tumors of infancy. They originate from embryonic fat and localize in soft tissues. We present the case of a lipoblastoma of the neck with localization in tracheal and esophageal walls that required an extended laryngotracheal and esophageal resection. To our knowledge, this is the first report of such localization of this tumor.

Pediatric lipoblastoma in the head and neck: a systematic review of 48 reported cases

BACKGROUND

Lipoblastoma is an exceedingly rare cause of pediatric head and neck masses. There have been 47 cases previously reported in the English literature. We present an additional case and review of the available literature on this rare neoplasm.

OBJECTIVE

To review and assess the current published literature regarding the efficacy of preserving neurovascular structures in the surgical management of pediatric lipoblastoma.

METHODS

Literature analysis of case reports was performed. MEDLINE was searched for the terms "neonatal lipoblastoma", "lipoblastomatosis", and "benign lipoblastoma". Results in the English literature were mined for relevant clinical data when available. The citations of case reviews found were searched to find additional cases.

RESULTS

Including our new case, a total of 48 cases of head and neck lipoblastoma have been reported in the English literature within 23 manuscripts. Four manuscripts presented cases series (Evidence Based Medicine Level 4) and 19 were case reports (Level 5). The median sample size was 1 (range 1-4). For those 14 articles (N=23 cases) reporting follow-up, the median follow-up duration was 22 months. Male to female ratio was 2.1:1 with an average age at presentation of 2.1 years (range: newborn to 12 years). Lesions ranged from 3 to 12 cm in longest diameter. Recurrence was seen in 27% of patients in which there was at least 1-year follow-up. The most common presenting symptoms were painless enlarging neck mass (53%, 17/32) and respiratory distress (12%, 4/32). An exact binomial sign test indicated that most authors recommend conservative complete excision with preservation of vital structures with 10 of 11 authors giving a stance supporting conservative surgical resection, p=.012.

CONCLUSIONS

Our findings suggest that although total excision is ideal and curative, subtotal resection may be a viable treatment alternative for lipoblastoma of the head and neck. This tumor presents a clinical challenge and should be considered in infants presenting with a cervical mass. It is difficult to differentiate from the much more common lymphangioma on clinical and radiological examination. Additionally, the potential for rapid growth and adhesion to neurovascular tissue makes surgical resection arduous. Nonetheless, recurrence rates for head and neck lipoblastomas are similar to those rates observed elsewhere in the body.

Classification and pathology

Soft tissue tumors are a heterogeneous group of benign and malignant processes. Some are assumed to be reactive; others are clearly neoplastic. Because of their rarity, they frequently pose diagnostic problems for surgical pathologists. Accurate diagnosis of these tumors is enhanced by knowledge of the clinical features of the given lesions and, at times, by application of immunohistochemical and molecular techniques. In this article the lesions are described essentially in accordance with the World Health Organization classification.

Omental lipoblastoma

A large intra-abdominal mass was discovered in a 6-month-old boy during a routine well-child examination. Imaging studies revealed a solid mass which appeared to arise from the left lobe of the liver, extending caudally and filling the entire pelvis. At the time of surgical excision, the mass was found to be unassociated with the liver, but was instead localized to the omentum. Histologic examination revealed adipocytes of varying stages of maturation arranged in a lobular architecture, consistent with a lipoblastoma. This unusual tumor is only the eighth reported omental lipoblastoma [J. Hicks, A. Dilley, D. Patel, J. Barrish, S. Zhu, M. Brandt, Lipoblastoma and lipoblastomatosis in infancy and childhood: histologic, ultrastructural, and cytogenetic features. Ultrastruct. Pathol. 25 (2001) 321-333; J. Harrer, G. Hammon, T. Wagner, M. Bolkenius, Lipoblastoma and lipoblastomatosis: a report of two cases and review of the literature. Eur. J. Pediatr. Surg. 11 (2001) 342-349; S. Weiss and J. Goldblum, Enzinger and Weiss's Soft Tissue Tumors, fourth ed., Mosby, St. Louis, MO, 2001, pp. 601-605, 670-686; S. Soin, S. Andronikou, R. Lisle, K. Platt, K. Lakhoo, Omental lipoblastoma in a child; diagnosis based in CT density measurements. J. Pediatr. Hematol. Oncol. 28(1) (2006) 57-58; A. Prando, S. Wallace, J.L. Marins, R.M. Pereira, E.R. de Oliveira, M. Alvarenga, Sonographic features of benign intraperitoneal lipomatous tumors in children-report of 4 cases. Pediatr. Radiol. 20(8) (1990) 571-574; C. Blank, E. Schoenmakers, P. Rogalla, E. Huys, A. Van Rijk, N. Drieschner, J. Bullerdiek, Intragenic breakpoint within RAD51L1 in a t(6;14)(p21.3;q24) of a pulmonary chondroid hamartoma. Cytogenet. Cell Genet. 95 (2001) 17-19; S. Ingraham, R. Lynch, S. Kathiresan, A. Buckler, A. Menon, hREC2, a RAD51-like gene, is disrupted by t(12;14)(q15;q24.1) in a uterine leiomyoma. Cancer Genet. Cytogenet. 115 (1999) 56-61]. Cytogenetics revealed a karyotype of 46,XY,t(8;14)(q13;q24). While lipoblastomas characteristically involve 8q, only one prior case has been reported with 14q24 as its fusion partner [M. He, K. Das, M. Blacksin, J. Benevenia, M. Hameed, A translocation involving the placental growth factor gene is identified in an epithelioid hemangioendothelioma. Cancer Genet. Cytogenet. 168 (2006) 150-154]. We report this unique case of an omental lipoblastoma with a focus on its unusual karyotype, as well as its differentiation from myxoid liposarcoma.

Cervical lipoblastoma: Case report, review of literature, and genetic analysis

BACKGROUND

Lipoblastoma is a rare, benign tumor of infants and children, usually occurring in the extremities and trunk, with only a few cases reported in the neck.

METHODS

We describe the case of an infant with a rapidly enlarging, painless neck mass. MRI revealed a 4-cm-diameter mass deep to the paraspinal muscles, in close proximity to the C2 vertebral foramen. Review of literature, diagnostic methods, and genetics of lipomatous tumors are discussed.

RESULTS

Complete surgical excision via a posterior cervical approach demonstrated irregular lobules of immature fat cells separated by a loose, myxoid connective tissue. Histology and genetic analysis confirmed the diagnosis of lipoblastoma.

CONCLUSION

Cervical lipoblastoma is rare, and typically presents as an asymptomatic, painless mass, rarely causing airway obstruction or nerve compression. MRI can be helpful in identifying the lipomatous nature of the mass, but the findings can be inconsistent due to variable maturity of fat cells and the mesenchymal content of the tumor. Chromosomal analysis is useful in differentiating lipoblastoma from liposarcoma. Recommended treatment is complete surgical excision.

Congenital combined orbito-nasal lipoblastoma: clinico-pathologic study

The authors present the clinical picture, histopathologic findings and surgical treatment of an infant born with a lipoblastoma involving an unusual combined orbito-nasal location. To the best of our knowledge, this is the first report of congenital lipoblastoma extension from orbit to the nasal cavity. Transconjunctival orbitotomy with excisional biopsy of tumor was performed. Histology specimen that demonstrates the small embryonal fat cells in different stages of maturation and the characteristic lobulation of the fat tissue are presented. The embryonic origin, timing of development of the tumor during gestation, as well as the route of propagation from orbit to nose are discussed. The authors conclude that complete excision of this tumor, with preservation of normal tissue, may bring cure to the young patient without gross functional deformity.

Spectrum of head and neck lesions diagnosed by fine-needle aspiration cytology in the pediatric population

Fine-needle aspiration cytology (FNAC) of the head and neck region is well accepted as a diagnostic procedure in the adult population. FNAC in the pediatric population is gaining acceptance as clinicians add this technique to the diagnostic armamentarium. An experience with FNAC of the head and neck region in the pediatric population is described from 2 large inner-city hospitals. Eighty-five cases were retrieved from patients age <18 years. In 52 cases, clinical or surgical follow-up was obtained and among these cases the specificity and sensitivity of FNA was 93% and 100%, respectively. The high specificity of FNAC allows the clinician to be confident of malignancy in a clinically suspicious lesion of the head and neck in a pediatric patient.

Congenital lipoblastoma in a neonate calf: first report in veterinary literature

Lipoblastoma is a rare benign tumour of adipose tissue that usually occurs in young children. Although around 100 cases of lipoblastoma have been reported in humans, no report has been previously described in animals. This case report describes the clinical and histopathological findings of a congenital lipoblastoma located at the tail base of a 2-day-old male calf. Grossly, the mass was pink with a partly ulcerated and haemorrhagic surface. The calf showed no neurological deficits. Radiographs of the vertebral column revealed no abnormalities, and surgical excision was performed. Histopathology of the mass was consistent with lipoblastoma. The calf was followed up for 13 months and found to be healthy with no signs of recurrence. To the best of the authors' knowledge, this is the first case of lipoblastoma in the veterinary literature. Lipoblastoma should thus be considered in the differential diagnosis list for congenital adipose tissue tumours in animals.

A thoracic wall lipoblastoma in a 3-month-old infant: A case report and review of the literature

Lipoblastoma is a rare benign tumor of adipose tissue seen almost always in infancy and early childhood. Lipoblastoma is present in 2 forms which are pathologically identical: circumscribed and diffuse. It is typically located in the extremities, and less frequently in head-neck region, trunk, and various organs. Lipoblastoma is a tumor with good prognosis with no reported metastases, despite its potential for local invasion and rapid growth. Our patient was a 3-month-old boy who was brought to our clinic for rapidly growing mass in the right hemithorax. With the aim of both diagnosis and treatment, the lipomatous mass was removed by local resection. In addition to the patient's age, histologic and cytogenetic analyses assisted the diagnosis of diffuse lipoblastoma. In the postoperative period, the thorax wall was unaffected, and after 6 years of follow-up no recurrence was observed. In the English literature, 8 cases of thoracic wall lipoblastoma have been previously reported, and only 3 of diffuse form. Here, we report, at our knowledge, the fourth case of thoracic diffuse lipoblastoma, in which cytogenetic analysis showed a previously undescribed karyotype aberration involving chromosomes 8, 13, and 16.

Lipoblastoma/lipoblastomatosis: a clinicopathologic study of 16 cases in Taiwan

Lipoblastoma/lipoblastomatosis is an uncommon benign lipomatous tumor affecting mainly infants and children. It presents as a painless mass located frequently in upper and lower extremities. The present study was conducted to characterize the clinicopathologic features of lipoblastoma/lipoblastomatosis in a Chinese population. A retrospective survey of 16 cases of pathologically confirmed lipoblastoma/lipoblastomatosis from 1988 to 2002 was performed. The available clinical information and histological sections were reviewed. The study involved 10 males and 6 females ranging in age from 5 to 49 months (median, 11.5 months). The patients presented with mass involving neck (n = 5), inguina (n = 3), feet (n = 2), arm (n = 1), leg (n = 1), thorax (n = 1), mesentery (n = 1), buttock (n = 1), and presacral region (n = 1). The lesions were removed surgically. Histologically, the majority (11/16) of primary tumors were of diffuse type. Follow-up ranging from 5 to 125 months was available in 13 patients. Four patients experienced a recurrence of tumors in the neck (n = 2) and lower extremities (n = 2) 11-84 months after operation. The most common site of involvement of lipoblastoma/lipoblastomatosis in our series was the neck. A follow-up period of more than 3 years is recommended for patients with this condition.

The spectrum of pediatric tumors in infancy, childhood, and adolescence: a comprehensive review with emphasis on special techniques in diagnosis

The spectrum of pediatric tumors varies considerably, from those derived from blastemal cells in various organ systems to proliferations of soft tissue supporting cells to hamartomatous processes that mimic malignant tumors. Small round cell tumors are often undifferentiated or poorly differentiated, making it difficult sometimes to provide a definitive diagnosis. Both benign and malignant tumors require a coordinated method for diagnosis, and need a comprehensive evaluation to provide the most appropriate diagnosis for designing therapy and predicting prognosis. Pediatric tumors require the integration of routine histopathologic examination with histochemical, immunocytochemical, ultrastructural, cytogenetic, and diagnostic molecular pathology techniques. This review provides updated guidelines with respect to the application of these special techniques in this rapidly evolving diagnostic arena.

Lipoblastoma of the neck: A rare cause of respiratory problems in children

Lipoblastomatous tumours are rare, and they occur primarily in children younger than 3 years of age. They are benign and may be divided in lipoblastomas and lipoblastomatosis. A case with cervical lipoblastoma causing respiratory difficulty is reported, and a clinical characterisation of patients with lipoblastomatous tumours in the neck is presented. A 6-year-old boy with complains of stridorous respiration and significant reduction in physical capacity was referred to the ENT Department, Odense University Hospital, Denmark. He was treated with total surgical resection of a soft and slowly growing tumour in the left side of the neck, extending from the base of the skull to the upper part of the mediastinum. The histological examination showed a lipoblastoma. After surgery all symptoms disappeared, and the patient was without any operative sequelae. Including the actual case, a review of English literature resulted in the identification of 37 patients with cervical lipoblastoma or lipoblastomatosis. However, in most cases the information was sparse, and only 13 patients were eligible for an analysis of basic clinical and demographic data. The median age was 25 months (range: 7-75 months), and the median tumour size 9 cm (range: 3-18 cm). No difference in sex distribution was found. Lipoblastomas (85%) seemed more frequent than lipoblastomatosis (15%). Stridorous respiration was present in 31%. It is concluded that a considerable part of lipoblastomatous tumours in the neck are combined with respiratory difficulties (31%), and that complete but gentle surgical treatment in most cases will restore normal physiological conditions.