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.

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.

Intrascrotal Lipoblastoma: A Rare Cause of Paratesticular Mass in a Pediatric Patient.

There is a broad differential diagnosis for a pre-pubertal child presenting with a scrotal mass including both benign and malignant etiologies. Lipoblastomas are rare benign neoplasms originating from fat cells that occur most commonly on the trunk or extremities of young children. There have been less than 20 cases of scrotal lipoblastomas reported in the literature, with the majority occurring in children less than 3 years of age. Here we present a unique case of an 18-month male presenting with a paratesticular mass found to be a lipoblastoma on final pathology.

[Lipoblastoma-like tumor of the vulva: A case report and review of the literature]. / Tumor vulvar similar a lipoblastoma: descripción de un nuevo caso y revisión de la literatura.

Lipoblastoma-like tumor of the vulva (LBLTV) was first described as a benign mesenchymal neoplasia; it was not recognized as a separate diagnosis in the 2013 WHO classification of soft-tissue tumors. To date, only 19 cases have been reported. LBLTV differential diagnosis includes other tumors of the vulvoperineal region and tumors with adipocytic differentiation, most of which are benign and thus a misdiagnosis has few clinical consequences. However, LBLTV may also mimic some aggressive lipomatous neoplasms. We describe a case of LBLTV in a 28 year-old woman and review the literature.

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

BACKGROUND: The hallmark of lipoblastoma is a PLAG1 fusion. PLAG1 protein overexpression has been reported in sporadic PLAG1-rearranged lipoblastomas. METHODS: We evaluated the utility of PLAG1 immunohistochemical staining (IHC) in 34 pediatric lipomatous tumors, correlating the results with histology and conventional cytogenetics, FISH and/or next generation sequencing (NGS) results. RESULTS: The study included 24 lipoblastomas, divided into 2 groups designated as "Lipoblastoma 1" with both lipoblastoma histology and PLAG1 rearrangement (n = 16) and "Lipoblastoma 2" with lipoblastoma histology but without PLAG1 cytogenetic rearrangement (n = 8), and 10 lipomas with neither lipoblastoma histology nor a PLAG1 rearrangement. Using the presence of a fusion as the "gold standard" for diagnosing lipoblastoma (Lipoblastoma 1), the sensitivity of PLAG1 IHC was 94%. Using histologic features alone (Lipoblastoma 1 + 2), the sensitivity was 96%. Specificity, as defined by the ability to distinguish lipoma from lipoblastoma, was 100%, as there were no false positives in the lipoma group. CONCLUSIONS: Cytogenetics/molecular testing is expensive and may not be ideal for detecting PLAG1 fusions because PLAG1 fusions are often cytogenetically cryptic and NGS panels may not include all partner genes. PLAG1 IHC is an inexpensive surrogate marker of PLAG1 fusions and may be useful in distinguishing lipoblastomas from lipomas.

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

BACKGROUND: Lipoblastoma is a rare benign mesenchymal neoplasm of infancy that most commonly occurs on the extremities and trunk but can arise at variable sites of the body. Retroperitoneal lipoblastomas are particularly rare but can grow to enormous size, and preoperative diagnosis is difficult with diverse, mostly malignant differential diagnoses that would lead to aggressive therapy. Since lipoblastoma is a benign tumor that has an excellent prognosis after resection, correct diagnosis is crucial. CASE PRESENTATION: A case of a large retroperitoneal tumor of a 24-month old infant that was clinically suspicious of a malignant tumor is presented. Due to proximity to the right kidney, clinically most probably a nephroblastoma or clear cell sarcoma of the kidney was suspected. Radiological findings were ambiguous. Therefore, the mass was biopsied, and histology revealed an adipocytic lesion. Although mostly composed of mature adipocytes, in view of the age of the patient, the differential diagnosis of a (maturing) lipoblastoma was raised, which was supported by molecular analysis demonstrating a HAS2-PLAG1 fusion. The tumor was completely resected, and further histopathological workup led to the final diagnosis of a 13 cm large retroperitoneal maturing lipoblastoma. The child recovered promptly from surgery and showed no evidence of recurrence so far. CONCLUSION: Although rare, lipoblastoma should be included in the differential diagnoses of retroperitoneal tumors in infants and children, and molecular diagnostic approaches could be a helpful diagnostic adjunct in challenging cases.

Congenital tongue base lipoblastoma causing neonatal airway compromise.

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

Lipoblastoma phenotype contains a somatic PIK3CA mutation.

Lipoblastoma typically occurs in childhood and is associated with rearrangements of the PLAG1 gene. We present a patient with an isolated mass thought to be a lipoblastoma clinically, radiographically, and histologically. The lesion was diagnosed as a PIK3CA-adipose lesion after the tissue was negative for PLAG1 rearrangement and contained a somatic PIK3CA mutation (H1047R). Although PIK3CA variants are associated with PROS (PIK3CA-related overgrowth spectrum), this report illustrates a non-syndromic, lipoblastoma phenotype caused by a PIK3CA mutation.

Lipoblastomatosis: An unusual midline neck mass in a young child.

Lipoblastomatosis is an extremely rare condition and is often not recognized prior to final pathologic analysis. In this case, a two-year-old female child presented with a non-tender, submental midline neck mass which had enlarged very slowly over the course of five months. The differential diagnosis included lipoma, lymphatic malformation, and thyroglossal duct cycst and a surgical excision was planned. The child was consented for a possible Sistrunk procedure if necessary. Intraoperatively, the mass was adherent to the hyoid bone and clear mucoid drainage was noted during resection leading the team to further weight the possibility of thyroglossal duct cyst and proceed with a Sistrunk procedure. Ultimately, final pathology revealed the diagnosis of lipoblastomatosis.

Ultrasonography of Pediatric Superficial Soft Tissue Tumors and Tumor-Like Lesions.

Ultrasonography (US) is usually the first imaging examination performed to evaluate palpable or visible superficial soft tissue lesions that are common in children. Although clinical assessments, such as age at presentation, clinical course, and overlying skin discoloration, are important for the differentiation of pediatric soft tissue lesions, US allows a specific diagnosis of some typical benign lesions and helps in guiding further investigation since it provides detailed information about the lesion location, characterization including solid versus cystic, vascularity, and compressibility. Therefore, sufficient knowledge of the normal anatomy, proper ultrasonographic techniques, and the imaging findings of common and uncommon soft tissue lesions in children are crucial for accurate assessment and management of patients. In this article, we review the techniques and imaging findings focusing on the ultrasonographic features of a variety of superficial soft tissue lesions detected in children.

Identification of a novel BOC-PLAG1 fusion gene in a case of lipoblastoma.

Lipoblastoma is a rare benign adipose tissue tumor that occurs mostly in infants and children. Histological diagnosis of lipoblastoma is sometimes difficult because it closely resembles other lipomatous tumors. The detection of PLAG1 gene rearrangement is useful for the diagnosis of lipoblastoma. Four PLAG1 fusion partner genes are known in lipoblastoma: HAS2 at 8q24.1, COL1A2 at 7q22, COL3A1 at 2q32, and RAB2A at 8q12. Herein, we describe a novel fusion gene in a case of lipoblastoma of left back origin. We identified a potential PLAG1 fusion partner using 5' rapid amplification of cDNA ends, and sequence analysis revealed the novel fusion gene, BOC-PLAG1. The BOC-PLAG1 fusion transcript consists of the first exon of the BOC gene fused to exon 2 or exon 3 of the PLAG1 gene. PLAG1 expression was found to be 35.7 ±â€¯2.1 times higher in the tumor specimen than in human adipocytes by qRT-PCR. As a result of the translocation, the constitutively active promoter of BOC leads to PLAG1 overexpression. The identification of the BOC-PLAG1 fusion gene will lead to more accurate diagnosis of lipoblastoma.

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

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

Submucosal Colonic Lipoblastoma Presenting With Colo-colonic Intussusception in an Infant.

Lipoblastoma is a benign adipose tumor typically presenting in infancy in superficial soft tissues of extremities. Intestinal complications secondary to intraabdominal or retroperitoneal involvement are exceedingly rare. We describe a unique case of a primary intestinal lipoblastoma arising from the submucosa of the transverse colon in an otherwise healthy 18-month-old boy. He presented with a history of reducible rectal prolapse, rectal bleeding, and episodic abdominal pain and was initially treated for constipation. Imaging identified a short colo-colonic intussusception, confirmed at laparotomy, and a fatty mass thought to arise from the mesentery. Pathological examination of the resected transverse colon revealed a submucosal tumor composed of a mixture of mature adipose tissue, foci of myxoid mesenchymal tissue with desmin positive, HMGA2 negative spindle cells, and scattered lipoblasts, characteristic of lipoblastoma. Lipoblastoma should be considered as a potential albeit rare cause of intussusception in young children, where a pathologic lead point is infrequently identified.

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.].

Gait disturbance and lower limb pain in a patient with PIK3CA-related disorder.

Post-zygotic activating mutations in PIK3CA and other genes encoding members of PI3K-AKT-mTOR pathway have been found in various overgrowth syndromes that have been grouped together as PIK3CA-related overgrowth spectrum (PROS). We report a female patient with gait disturbance, leg pain, isolated macrodactyly of the foot, and mild intellectual disability. Imaging of the lower limb showed a lipoblastoma of the right thigh. A mosaic gain-of-function mutation in the catalytic domain of PIK3CA (c.3140 A > G; p.His1047Arg) was detected in the adipose tissue and in skin cultured fibroblasts from the macrodactyly but not in blood. The leg pain and the severe walking disturbance improved slightly over time and serial MRI of the lower limbs suggested that the size of the lipoblastoma relative to the lower limb muscles or to the whole lower limb was unchanged as consequence of limb growth. This case report illustrates that pain and gait disturbance can be features of PROS and highlights the need of better knowledge about the natural history of the disease.

Lipoblastoma in children: Review of 12 cases.

BACKGROUND: Lipoblastoma is a rare benign mesenchymal tumor of infancy and early childhood. Symptoms vary depending on localization, and signs of compression of adjacent organs may be seen. METHODS: A total of 12 children with pathologically proven lipoblastoma from 2000 to 2014 were reviewed retrospectively for their clinical features, treatment and follow up. RESULTS: There were seven boys and five girls between 7.5 months and 7.5 years of age. The most common symptom was painless rapid-growing mass. The tumors were located in the neck, the abdomen, the groin, pelvis, axilla, glutea, labium majus, thigh and trunk. The largest tumor was in a retroperitoneal location and was 13 × 10 cm in size. Complete resection was performed in 10 patients. All of these patients were followed without any evidence of recurrence. Subtotal excision was performed in two patients. At a median follow up of 38 months (range, 1.8 months-10 years), all patients were disease free. CONCLUSIONS: Lipoblastoma should be considered in the differential diagnosis of rapidly growing mass in patients <3 years of age. Total excision is the treatment of choice with preservation of vital organs. The prognosis is excellent despite large tumor size and local invasion. Recurrence rate is high in incompletely resected tumors. Regular follow up is important for early detection of recurrence.

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

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