Evidence by spectral karyotyping that 8q11.2 is nonrandomly involved in lipoblastoma

Lipoblastoma presenting as a rapidly growing paravertebral mass and masquerading as myxoid liposarcoma on fine needle aspiration cytology

Lipoblastoma is a peculiar variant of lipoma occurring almost exclusively during infancy and early childhood. It is found most commonly in the upper and lower extremities; less common sites are head and neck, trunk, mediastinum, and retroperitoneum. It has a greater predilection for boys and commonly presents as a slowly growing soft-tissue mass. We present here the case of a five- year old female child with a lipoblastoma presenting as a paravertebral mass in the right lower back which progressed rapidly in the previous six months causing diagnostic difficulty on fine needle aspiration cytology.

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.

Lipoblastoma of the hand and cleft palate: is there a genetic association?

We report a case of lipoblastoma of the hand in a 19-month-old female patient with a history of cleft palate. The incidence of lipoblastoma and cleft palate individually is extremely rare. To the best of our knowledge, only 1 other case of a patient with both cleft palate and lipoblastoma exists in the literature. Lipoblastoma is a rare benign neoplasm in adipose tissue almost exclusively found in children younger than 3 years. Cytogenetic testing has shown that lipoblastomas characteristically share a clonal chromosomal rearrangement affecting the long arm of chromosome 8. Furthermore, recent research has shown that the 8q chromosome is an important genetic risk factor for cleft palate development. We describe the second case linking cleft palate with this rare tumor and provide evidence for a potential genetic association.

An isolated digital lipoblastoma

This report presents a girl with a lipoblastoma of a finger presenting as a macrodactyly. Documented inflammation of the digit at birth raises suspicion of neo-adipogenesis, which is recognised in lipomas. This case highlights a rare site for lipoblastomas and explores a potential aetiopathogenesis.

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.

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.

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.

Spectral karyotyping of human, mouse, rat and ape chromosomes--applications for genetic diagnostics and research

Spectral karyotyping (SKY) is a widely used methodology to identify genetic aberrations. Multicolor fluorescence in situ hybridization using chromosome painting probes in individual colors for all metaphase chromosomes at once is combined with a unique spectral measurement and analysis system to automatically classify normal and aberrant chromosomes. Based on countless studies and investigations in many laboratories worldwide, numerous new chromosome translocations and other aberrations have been identified in clinical and tumor cytogenetics. Thus, gene identification studies have been facilitated resulting in the dissection of tumor development and progression. For example, different translocation partners of the TEL/ETV6 transcription factor that is specially required for hematopoiesis within the bone marrow were identified. Also, the correct classification of complex karyotypes of solid tumors supports the prognostication of cancer patients. Important accomplishments for patients with genetic diseases, leukemias and lymphomas, mesenchymal tumors and solid cancers are summarized and exemplified. Furthermore, studies of disease mechanisms such as centromeric DNA breakage, DNA double strand break repair, telomere shortening and radiation-induced neoplastic transformation have been accompanied by SKY analyses. Besides the hybridization of human chromosomes, mouse karyotyping has also contributed to the comprehensive characterization of mouse models of human disease and for gene therapy studies.

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 and lipoblastomatosis

We report two cases of lipoblastoma of the buttock in a 10-month-old boy and a 20-month-old girl, the first with rearrangement of chromosome 8 and the second without cytogenetic abnormality, and one case of lipoblastomatosis of a leg in a 6-month-old boy with a normal karyotype but with a rearrangement of the PLAG1 gene. Lipoblastoma and lipoblastomatosis are two different presentation of the same rare benign soft tissue mesenchymal tumour arising from fetal white fat and occurring almost exclusively in young children under 3 years. These neoplasms have no malignant potential but may recur in cases of incomplete resection. Histological diagnosis sometimes used to be difficult because of the close resemblance of the lesion with myxoïd liposarcoma. Nowadays, cytogenetic analysis may contribute to the diagnosis by showing abnormalities of the long arm of chromosome 8, leading to rearrangement of the PLAG1 gene. Actual advances in cytogenetic molecular analysis may aid in accurate diagnosis.

Cervical lipoblastomatosis producing quadriparesis: case report of surgery with chemotherapy and 10-year follow-up

INTRODUCTION

Cervical lipoblastomatosis is a rare spinal tumour. Management of recurrence and long-term outcome data are not well described.

CASE REPORT

A 10-month-old infant presented with an upper extremity weakness. Magnetic resonance imaging (MRI) revealed an extradural cervical spinal tumour. It was debulked and histopathology revealed it to be lipoblastomatosis. The infant improved postoperatively. However, 5 months later the patient deteriorated and developed quadriparesis. The patient was managed with a more extensive resection and had chemotherapy. Ten years post-presentation the patient is well having made a full recovery and is living a normal life. Recent MRI shows minimal residual quiescent tumour.

CONCLUSION

The treatment of cervical lipoblastomatosis should involve the resection of as much tumour as possible at the first sitting as recurrence can be a problem. In cases of spinal recurrence we recommend aggressive decompression and adjuvant chemotherapy.

Molecular cytogenetic characterization of a case of Müllerian adenosarcoma

Müllerian adenosarcoma is a distinctive type of mixed Müllerian tumor of the female genital tract. To our knowledge, no cytogenetic data have been documented on Müllerian adenosarcoma in the literature so far. We report here the chromosomal findings of a Müllerian adenosarcoma in a 15-year-old female. Cytogenetic and molecular cytogenetic analysis revealed a complex karyotype involving chromosomes 2, 8, 10, 13, 19, and 21. These numerical and structural abnormalities may be of etiologic significance. This report may highlight the potential value of molecular cytogenetic analysis in differential diagnosis of Müllerian tumors. More cases are warranted to further genetically characterize this type of neoplasm.

Pulmonary lipoblastoma in an 18-month-old child: a unique tumor in children

Lipoblastoma, a rare benign tumor of adipose tissue, typically occurs in the superficial or deep layers of soft tissue on the trunk or extremities. Other sites of occurrence include the head, neck, and retroperitoneum. Lipoblastoma of the chest wall and parietal pleural have been reported, but occurrence within the lung has not been previously described. We report a case of pulmonary lipoblastoma in a young child presenting with complete opacification of the left hemithorax and mediastinal shift on chest radiograph. A lobectomy was performed, and the diagnosis was made by histological examination.

Cytogenetic-clinicopathologic correlations in rhabdomyosarcoma: a report of five cases

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children younger than the age of 15 years. Histologically, RMS can be subdivided into two major subtypes; embryonal (E-RMS) and alveolar (A-RMS) rhabdomyosarcoma, with E-RMS being the more common. Although cytogenetic and molecular genetic findings have been reported extensively for RMS, clinicopathologic-genetic correlations among these tumors have not been reported in detail. In this report, we correlate the cytogenetic findings, including fluorescence in situ hybridization and spectral karyotyping, with pathologic findings and outcome for five RMS, including two A-RMS, one E-RMS, one botryoid RMS, and one anaplastic nonclassified RMS (N-RMS). The findings in A-RMS and E-RMS generally were consistent with previous reports; however, gain of chromosome 7 in A-RMS and gain of chromosome 9 segments in E-RMS observed here have seldom been reported in the literature. Importantly, the botryoid RMS had a cytogenetic profile similar to other types of E-RMS. An add(11)(q21) observed in this tumor, together with a t(8;11)(q12 approximately 13;q21) reported previously, indicates that 11q21 rearrangements may be nonrandomly related to botryoid RMS. In addition, the N-RMS expressed a cytogenetic pattern similar to that observed in E-RMS, thus providing genetic evidence that anaplastic N-RMS is a variant of E-RMS. Finally, these cases provide cogent evidence for the diagnostic and prognostic significance of the pathologic-genetic classification of RMS.