Lipoblastoma: uma série de casos e seus achados de imagem / Lipoblastoma: a serie of cases and their imaging findings

Objetivo: Mostrar imagens com diferentes características encontradas nos diagnósticos de lipoblastoma. Relato do Caso: Foram realizadas análises de imagens e quadros clínicos de três crianças menores de 3 anos que apresentaram lesão expansiva de crescimento rápido, cujo diagnóstico histopatológico da lesão foi lipoblastoma, sendo dois do sexo feminino e um masculino, entre os anos 2014-2022. Discussão: O exame por radiografia dasextremidades demonstrou aumento de partes moles sem comprometimento ósseo associado. As tomografias computadorizadas apresentaram formação expansiva heterogênea com densidade predominantemente de gordura, com areas sólidas e císticas. A ressonância permitiu caracterizar com mais precisão a doença, fornecendo o aspecto da mesma, a intensidade de sinal, realce pelo meio de contraste, permitindoavaliação mais precisa dos tecidos de partes moles e áreas císticas. Conclusão: Uma avaliação imagiológica pré-operatória deve ser realizada para determinar a extensão da doença e ajudar no planejamento cirúrgico. A excisão cirúrgica não mutilante permanece como terapêutica de escolha. Ressaltamos através desse relato de casos que, na identificação de um tumor composto principalmente por gordura, deverá ser aventada a hipótese diagnóstica de lipoblastoma na faixa pediátrica

Objective: We aimed to show images with different characteristics found in lipoblastoma diagnoses. Case Report: We performed Images and clinical analysis on three children under 3 years of age, who suffered a rapidly growing, expansive lesion whose histopathological diagnosis of the lesion was lipoblastoma, two of which were female and one male, among the years 2014-2022. Discussion: Radiographic examination of the extremities demonstrated an increase in soft tissues without associated bone involvement. The CT scans showed heterogeneous expansive formation with predominantly fat density, with solid and cystic areas. MRI allowed us to more accurately characterize the disease, providing its appearance and signal intensity, real through the contrast medium, allowing more precise assessment of soft tissue tissues and cystic areas. Conclusion: A preoperative imaging evaluation should be performed to determine the extent of the disease and aid in surgical planning. Non-mutilating surgical excision remains the therapy of choice. We emphasize through this case report that the identification of a tumor composed mainly of fat should point to the diagnostic hypothesis of lipoblastoma in the pediatric population

Localización atípica de un lipoblastoma en una niña de 5 años / Atypical location of lipoblastoma in a 5-year-old girl

Se informa de un lipoblastoma perineal en una niña de 5 años localizado en el labio mayor derecho. La lesión aumentó gradualmente en 6 meses. En la ecografía y la resonancia magnética (RM), se observó un tumor heterogéneo sólido limitado con componente graso. Tras su extirpación quirúrgica, el estudio anatomopatológico confirmó un lipoblastoma. El lipoblastoma es un tumor mesenquimatoso benigno poco frecuente de la lactancia y la primera infancia. Los síntomas varían en función de la localización; pueden observarse signos de compresión de los órganos adyacentes. Este tipo de tumores inusuales de los tejidos blandos son más frecuentes en menores de 3 años. Los lipoblastomas se localizan predominantemente en las extremidades, pero también pueden encontrarse en la cabeza y el cuello, el tronco, el mediastino, el riñón, el mesenterio, el retroperitoneo y el perineo. Se debe sospechar su presencia en función de los hallazgos de la ecografía y la RM.

We reported a perineal lipoblastoma in a 5-year-old girl located in the right labia mayor. The lesion gradually increased within 6 months. Ultrasound and magnetic resonance imaging (MRI) showed a limited solid heterogenous tumor with fatty component. After it had been surgically removed, the anatomopathological examination confirmed that it was a lipoblastoma. Lipoblastoma is a rare benign mesenchymal tumor of infancy and early childhood. Symptoms vary depending on localization; signs of compression of adjacent organs may be seen. This type of unusual soft tissue tumors occurred most often in under 3 years old. The localization of lipoblastomas is predominantly in the extremities but may be also found in other sites including the head and neck, trunk, mediastinum, kidney, mesentery, retropritoneum and perineum. The suspicion should be considered according to ultrasound and MRI findings.

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

BACKGROUND: Lipoblastoma is a rare and benign tumor arising from embryonal fat cells. It develops primarily in infancy and early childhood. We present a case study of a 10-month-old child treated for an extensive tumor of the infratemporal fossa and parapharyngeal space. The systematic review of 60 reports in 80 children with lipoblastoma of the head and neck is also reported. MATERIAL AND METHODS: Systematic review of all articles included lipoblastomas of the head and neck area in children published from 1964 to 2022 in the PubMed database was conducted. Clinical presentation of extensive lipoblastoma of the head and neck in a child. RESULTS: On the basis of all inclusion criteria 83 articles were identified concerning pediatric lipoblastoma. There were 36 F (45%) and 39 M (48%), in 6 patients, (7%) gender was not specified. Ages ranged from 0mth (6h) to 15 yo (180mth). The tumor was located in the head in 22 (27%) cases, while the neck area accounted for 53 (65%) cases. General description without precise location was shown in 6 (7%) cases. All patients underwent complete surgical excision. Post surgical recurrence was noted in 6% clinical cases in the analyzed articles. CONCLUSIONS: Lipoblastoma is characterized by a rapidly growing predominantly adipose mass. The treatment of choice is complete surgical excision. In selected cases when the pathology is hard to reach, as a consequence of the extensive penetration of the mass, we recommend performing the procedure with an interdisciplinary team. Endoscopy assistance and microdebrider significantly facilitated the removal of pathology in the described advanced case of lipoblastoma. This is the only case reported in the pediatric literature of a head and neck lipoblastoma, where due to extensive involvement and location of the disease the cranial nerves V2 and inferior alveolar branch of V3 could not be spared. Long-term follow-up even to 10 years is required because there is a reported tendency for these tumors to recur.

Lipoblastoma Arising in the Head and Neck: A Clinicopathologic Analysis of 20 Cases.

BACKGROUND: Lipoblastomas (LPBs) are benign adipocytic neoplasms believed to recapitulate the development of embryonal fat. METHODS: We investigated the clinicopathologic and immunohistochemical features of 20 lipoblastomas arising in the head and neck in 18 patients. RESULTS: Patients included 6 males and 12 females (1:2 ratio) with age at diagnosis ranging from 4 months to 28 years. Tumors occurred more commonly in the neck (12, 66.7%) and less commonly in the forehead, scalp, and tongue (2, 11.1%). Tumor size ranged from 1.4 to 6.0 cm (median 5.0 cm). Two patients, a 4-month-old female and 3-year-old male, had local recurrence of neck tumors at 4 months and 3 years after excision, respectively. Microscopically, tumors had a lobulated growth pattern and consisted of adipocytes at varying stages of differentiation. In addition to the classical histologic features, lipoma-like and myxoid variants constituted 45% of cases. Metaplastic elements, including brown fat and cartilage, were identified in two cases. CONCLUSIONS: LPBs arising in the head and neck region are not uncommon and occurred at a rate of 9% in our cohort. They should be kept in the differential diagnosis when a fatty tumor is encountered in an older child or occurring at an unusual location.

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

INTRODUCTION: Lipoblastoma and lipoblastomatosis are rare benign mesenchymal adipose tumors that originate from embryonic white adipocytes and occur most commonly in infancy and early childhood. Lipoblastomas occur in the extremities and trunk, including the retroperitoneum and peritoneal cavity. Therefore, infiltration into the spinal canal has rarely been reported. CASE PRESENTATION: A 4-year-old girl presented to our clinic because of difficulty sitting on the floor with her legs straight. She also complained of enuresis and constipation for the past 6 months with persistent headaches and back pain evoked by body anteflexion. A magnetic resonance imaging revealed a massive lesion of the psoas major muscle, retroperitoneal, and subcutaneous spaces, extending into the spinal epidural space between L2 and S1. The patient underwent surgery which resulted in gross total removal of the tumor from the spinal canal. The mass was yellowish, soft, lobulated, fatty, and easily removed from the surrounding structures. Pathology confirmed the diagnosis of lipoblastoma. The postoperative course was uneventful, and the patient was discharged without any signs of neurological deficit. CONCLUSION: We herein discuss a rare case of lipoblastoma extending into the spinal canal, resulting in neurological symptoms. Although this tumor is benign with no potential for metastasis, it is prone to local recurrence. Therefore, close postoperative observation should be performed.

Lipoblastoma-Like Tumor and Fibrosarcoma-Like Lipomatous Neoplasm Represent the Same Entity: A Clinicopathologic and Molecular Genetic Study of 23 Cases Occurring in Both Men and Women at Diverse Locations.

Lipoblastoma-like tumor (LLT) is a benign soft tissue tumor demonstrating mixed morphologic features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma but lacking genetic alterations associated with those tumors. LLT was originally thought to be specific to the vulva but has since been reported in the paratesticular region. The morphologic features of LLT overlap with those of "fibrosarcoma-like lipomatous neoplasm" (FLLN), a rare, indolent adipocytic neoplasm considered by some to form part of the spectrum of atypical spindle cell and pleomorphic lipomatous tumor. We compared the morphologic, immunohistochemical, and genetic features of 23 tumors previously classified as LLT (n = 17) and FLLN (n = 6). The 23 tumors occurred in 13 women and 10 men (mean age, 42 years; range, 17 to 80 years). Eighteen (78%) cases arose in the inguinogenital region, whereas 5 tumors (22%) involved noninguinogenital soft tissue, including the flank (n = 1), shoulder (n = 1), foot (n = 1), forearm (n = 1), and chest wall (n = 1). Microscopically, the tumors were lobulated and septated, with variably collagenized fibromyxoid stroma, prominent thin-walled vessels, scattered univacuolated or bivacuolated lipoblasts, and a minor component of mature adipose tissue. Using immunohistochemistry, 5 tumors (42%) showed complete RB1 loss, with partial loss in 7 cases (58%). RNA sequencing, chromosomal microarray, and DNA next-generation sequencing study results were negative for significant alterations. There were no clinical, morphologic, immunohistochemical, or molecular genetic differences between cases previously classified as LLT or FLLN. Clinical follow-up (11 patients [48%]; range, 2-276 months; mean, 48.2 months) showed all patients were alive without disease, and only one patient had experienced a single local recurrence. We conclude that LLT and FLLN represent the same entity, for which "LLT" seems most appropriate. LLT may occur in either sex and any superficial soft tissue location. Careful morphologic study and appropriate ancillary testing should allow for the distinction of LLT from its potential mimics.

Pérdida ponderal como debut de lipoblastoma mesentérico en un lactante / Weight loss as clinical presentation of mesenteric lipoblastoma in an infant

Introducción: el estancamiento ponderal durante el segundo año de vida es un motivo frecuente de consulta que requiere seguimiento y, en ocasiones, pruebas complementarias con el fin de descartar las causas más frecuentes a esta edad, tales como infecciones o síndromes malabsortivos. Se presenta el caso de un lactante con estancamiento ponderal de etiología poco frecuente. Caso clínico: varón que a partir de los 15 meses de edad comienza con pérdida ponderal, con apetito y estado general conservados, sin otros síntomas. Se objetiva un descenso de peso desde el percentil 75 hasta el percentil 25 a lo largo de tres meses, sin repercusión en la talla ni el perímetro cefálico. A la exploración física tenía aspecto desnutrido, con distensión y timpanismo abdominal. Se solicitan pruebas complementarias, incluyendo anticuerpos de celiaquía por sospecha de síndrome malabsortivo, que fueron normales. En la ecografía abdominal se observa imagen compatible con tumoración de gran tamaño. Ante estos hallazgos, se amplían pruebas de imagen mediante tomografía computarizada (TC) y resonancia magnética (RM) abdominales, donde se encuentra una imagen compatible con lipoblastoma mesentérico. Se interviene quirúrgicamente a los 20 meses, confirmándose en el estudio histológico el diagnóstico de sospecha. Conclusión: los lipoblastomas son tumores benignos, infrecuentes, prácticamente exclusivos de la edad pediátrica. Generalmente se localizan en zonas superficiales, siendo estos asintomáticos. Los de localización profunda, como el del caso descrito, son excepcionales y pueden producir síntomas secundarios a compresión local. El diagnóstico definitivo se realiza mediante estudio histológico, siendo la exéresis el tratamiento de elección (AU)

Introduction: loss weight in the second year of life is a frequent reason for consultation that requires follow-up and sometimes work up complementary in order to rule out the most frequent causes at this age, such as infections or malabsorptive diseases. We present the case of an infant with weight stagnation secondary to an unfrequent cause.Clinical case: a male began with weight loss at 15 months of age, with appetite and general condition preserved without other symptoms. A decrease in weight percentile was observed from 75th to the 25th percentile over three months without repercussions on height or head circumference. On physical examination, he appeared thinned, with abdominal distension and tympanism. Complementary tests, including celiac disease antibodies to suspected malabsorptive syndrome were ordered, without patological findings. Abdominal ultrasound showed an image compatible with a big tumor. With these findings, an abdominal CT scan and MRI were performed, and an image compatible with mesenteric lipoblastoma was found. Surgery was performed at 20 months, supporting the suspected diagnosis in the histological study.Conclusion: lipoblastomas are infrequent benign tumors, mainly exclusive of the pediatric age. Frecuently, they are located in superficial areas, and are asymptomatic. Those of deep localization, as the described case, are usually exceptional, and may present symptoms secondary to local compression. The definitive diagnosis is made by histological study and the removal the treatment of choice. (AU)

Primary cardiac lipoblastoma of the right atrium.

Lipoblastoma is a rare neoplasm of the embryonal white fat. It occurs most commonly in children under the age of 3 years and usually inflicts the superficial soft tissues of trunk and extremities. We present the case of a 3-year-old male patient with a successfully resected primary cardiac right-atrial lipoblastoma with COL1A2::PLAG1 gene fusion.

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.

Atypical location of lipoblastoma in a 5-year-old girl. / Localización atípica de un lipoblastoma en una niña de 5 años.

We reported a perineal lipoblastoma in a 5-year-old girl located in the right labia mayor. The lesion gradually increased within 6 months. Ultrasound and magnetic resonance imaging (MRI) showed a limited solid heterogenous tumor with fatty component. After it had been surgically removed, the anatomopathological examination confirmed that it was a lipoblastoma. Lipoblastoma is a rare benign mesenchymal tumor of infancy and early childhood. Symptoms vary depending on localization; signs of compression of adjacent organs may be seen. This type of unusual soft tissue tumors occurred most often in under 3 years old. The localization of lipoblastomas is predominantly in the extremities but may be also found in other sites including the head and neck, trunk, mediastinum, kidney, mesentery, retropritoneum and perineum. The suspicion should be considered according to ultrasound and MRI findings.

Se informa de un lipoblastoma perineal en una niña de 5 años localizado en el labio mayor derecho. La lesión aumentó gradualmente en 6 meses. En la ecografía y la resonancia magnética (RM), se observó un tumor heterogéneo sólido limitado con componente graso. Tras su extirpación quirúrgica, el estudio anatomopatológico confirmó un lipoblastoma. El lipoblastoma es un tumor mesenquimatoso benigno poco frecuente de la lactancia y la primera infancia. Los síntomas varían en función de la localización; pueden observarse signos de compresión de los órganos adyacentes. Este tipo de tumores inusuales de los tejidos blandos son más frecuentes en menores de 3 años. Los lipoblastomas se localizan predominantemente en las extremidades, pero también pueden encontrarse en la cabeza y el cuello, el tronco, el mediastino, el riñón, el mesenterio, el retroperitoneo y el perineo. Se debe sospechar su presencia en función de los hallazgos de la ecografía y la RM.

Metastatic lipoblastoma-like tumour.

INTRODUCTION: Lipoblastoma-like tumours (LLT) are uncommon and their biologic nature is not well-understood. Complete resection of the primary lesion is usually curative. This is the first reported case of metastatic LLT. CASE PRESENTATION AND MANAGEMENT: This patient originally had a large primary resected from the vulva. She subsequently developed tumours in multiple areas including her right pleura and lung. These were resected and pathology was consistent with LLT. On follow-up imaging, there was evidence of metastatic disease. CONCLUSION: The patient is currently undergoing detailed molecular analysis in the hope of detecting a molecular target. Given the infrequent occurrence of LLT, its behaviour is not well understood. Longer duration of follow up is required and prognostic markers need to be identified to better direct treatment.

Myxolipoma of hand in a child: case report of a rare tumor.

Lipomatous tumors account for less than 10% of tumors in the pediatric population. Myxolipomas (a subset of lipoma characterised by mature adipose tissue and abundant mucoid substance) are found to be even rarer. There are a few case reports in different body parts like heart, kidney, oral cavity, epiglottis, cervical and mediastinal regions. However, there are no case reports on the involvement of the hands in any age group. High resolution ultrasound is the imaging modality of choice for the initial evaluation of superficial soft tissue tumors, their site, nature and extent. In conjunction with clinical findings and age of presentation, it helps in narrowing down the differential diagnosis and planning the management. Hyperechoic fatty tumors in the pediatric hand are mostly benign and includes lipomas, lipoblastomas and fibrous hamartomas of infancy as the main differentials. A definitive diagnosis is based on a histo-pathological and molecular cytogenetic examination. This article presents a never before reported case of a rare, large, myxolipoma of the hand in a 22-month-old boy.

Fatal course of a benign mediastinal lipoblastoma in a 20-year-old woman.

Lipoblastoma is a rare benign, but highly proliferative tumor most commonly seen in early childhood. Recurrence rates are high when complete resection is unfeasible and systemic therapy is necessary. We report the case of a large, aggressive thoracic and mediastinal lipoblastoma in a 20-year-old woman, which was surgically not resectable. The tumor has been characterized extensively including molecular pathology, molecular karyotyping, conventional chromosomal analysis and in vitro-chemosensitivity testing in search for alternative therapies. Nevertheless, this did not reveal treatable targets and systemic therapies, which were based on chemosensitivity testing proved ineffective. Despite all treatment attempts, the disease showed a progressive fatal course.

Diagnosis and treatment of benign adipocytic tumors in children.

PURPOSE: To describe demographic, clinical, diagnostic and therapeutic aspects of pediatric patients with benign adipocytic tumors admitted to a high complexity teaching hospital from 2007 to 2021. METHODS: Retrospective observational descriptive study. Patient information was retrieved from clinical records. A descriptive analysis was carried out for qualitative data and frequencies were calculated for quantitative data. RESULTS: 76 patients were included with a mean age of 7.5 years old where 60.5% were boys. The main symptom was a mass (73.7%) mostly found in the lower limbs (23.6%). Congenital birth defects were identified in 48.6% of the cases. Preoperative imaging was available in 78.9% of the patients allowing characterization of lesions or differential diagnosis. The therapeutic goal was resection with negative margins, which was feasible in all cases except for one case. The histopathological diagnosis was lipoma in 68.4% of the cases followed by lipoblastoma in 13.1%. The mean follow-up period was 17.9 months. 79.7% of the patients were asymptomatic at their last out-patient visit. CONCLUSION: Benign adipocytic tumors constitute a wide spectrum of lesions, which involve diverse anatomic segments from the neural axis to the inguinoscrotal region. The present work contributes to the general understanding of the clinical presentation and differential diagnosis for these infrequent neoplasms.

Lipoblastoma of the extremities.

BACKGROUND: Lipoblastoma is a rare benign tumor of infancy and childhood, with similar radiographic imaging findings as malignant liposarcoma. Therefore, it is crucial to distinguish through other diagnostics and clinical features. We present our experience with the diagnosis and clinical management of this entity. METHODS: A retrospective chart review was performed to identify children treated for lipoblastoma at our institution over a 30-year period. Charts were evaluated for diagnostic methods, treatment, and recurrence risk. RESULTS: A total of 9 males and 3 females were identified. The age at diagnosis ranged from 8 months to 44 years. Imaging modalities employed included ultrasound (N = 5), MRI (N = 12), X-ray (N = 8), and CT (N = 3). The tumor location was reported in the lower extremity (N = 8) and upper extremity (N = 4). The tumor size ranged from 1.7 to 18 cm (mean=7.08 cm). All patients underwent complete resection. Available pathology reports noted masses featuring mature adipocytes (N = 1), fibrous septa (N = 2), focal myxoid changes (N = 1), and spindle cells (N = 2). Nine patients underwent chromosomal analysis, which demonstrated five chromosome 8 abnormalities. No recurrences were reported. Three patients had follow-up imaging, and 11 had follow-up visits between 2 weeks to 15 years. CONCLUSION: Lipoblastoma is an uncommon childhood neoplasm of embryonic white fat that can also be present in adolescence and adulthood. Imaging, especially MRI, is helpful in limiting the differential diagnosis, but definitive diagnosis requires tissue biopsy, which should be obtained with core biopsy rather than fine needle aspiration. Surgical resection is curative with few complications. We do not recommend routine monitoring as recurrence is unlikely.

Pediatric fibromyxoid tumor with PLAG1 fusion: An emerging entity with a novel intracranial location.

Translocations involving PLAG1 occur in several tumors, most commonly pleomorphic adenoma and lipoblastoma. Recently, a distinctive soft tissue tumor with a PLAG1 fusion has been reported in the pediatric age group. These are low grade tumors with a fibroblastic or mixed fibroblastic and myxoid morphology but no other lines of differentiation. They are typically immunopositive for desmin and CD34. The partner genes for these tumors have included YWHAZ, EEF1A1, ZFHX4l, CHCHD7, and PCMTD1. We report another case of this fibromyxoid tumor with a PLAG1 fusion, this time with COL3A1 as the partner gene. The fusion placed expression of a full-length PLAG1 protein under the control of the constitutively active COL3A1 promoter. Overexpression of PLAG1 was confirmed by diffusely positive immunostaining for PLAG1. The most novel aspect of this tumor is the intracranial location. Opinion has been divided over whether these tumors are a specific entity, or related to lipoblastoma, since that tumor also typically occurs in soft tissue in the pediatric age group and shows many of the same gene fusions. However, lipoblastoma has never been reported in an intracranial location and, thus, our case provides compelling evidence that this fibromyxoid tumor is indeed a distinct entity.