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.

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.

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

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

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.

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.

[Pathological significance of NY-ESO-1 expression in the diagnosis of myxoid liposarcoma].

Objective: To detect the expression of New York esophageal squamous cell carcinoma antigen 1 (NY-ESO-1) in common types of mesenchymal myxoid tumors, and to investigate its significance in the diagnosis and differential diagnosis of myxoid liposarcoma. Methods: A total of 43 formalin-fixed paraffin-embedded samples of mesenchymal myxoid tumors from the Affiliated Hospital of Qingdao University and Qingdao Municipal Hospital ranging between 2010 and 2017 were selected. NY-ESO-1 expression was detected by immunohistochemical staining. DDIT3 gene status was detected by fluorescence in situ hybridization (FISH). NY-ESO-1 mRNA was detected by reverse transcription-PCR (RT-PCR). Results: Histopathology and FISH results confirmed that there were 11 cases of myxoid liposarcoma and 32 other types (including 7 cases of well-differentiated liposarcoma, 1 dedifferentiated liposarcoma, 3 lipomas, 2 lipoblastomas and 19 non-adipocytic tumors). Immunohistochemical staining showed that the positive expression propotion of NY-ESO-1 in myxoid liposarcoma was 11/11, and the positive location was the cytoplasm and nucleus of lipoblast cells. The expression intensity is higher in regions with round cell differentiation. Among the 32 cases of other mesenchymal myxoid tumors, only one well-differentiated liposarcoma showed positive immunoreactivity for NY-ESO-1. RT-PCR confirmed that 7 cases of myxoid liposarcoma (7/11) and one well-differentiated liposarcoma (1/7) had NY-ESO-1 mRNA expression. Conclusions: NY-ESO-1 is positively expressed in myxoid liposarcoma. It can be served as a useful marker for the diagnosis and differential diagnosis of myxoid liposarcoma.

Rare retro peritoneal tumor in infants.

Lipoblastoma is a rare mesenchymal tumor, occuring in less than three-year-old infants in 90% of the cases and in 40% of the cases in chidren aged less than one year. It can be present at birth. It is a benign tumor, with defined margins, that can be locally aggressive, without metastases. We report the case of retroperitoneal lipoblastomatosis, with a neonatal diagnosis made by ultrasonographic and CT features.

Varied Presentations of Pediatric Lipoblastoma: Case Series and Review of the Literature.

Lipoblastoma is a rare neoplasm of embryonal adipose tissue most often encountered on the trunk and extremities of children. It commonly presents as a painless subcutaneous soft tissue mass, but there are other unique clinical presentations that are important to recognize. The differential is broad and includes sarcoma, vascular tumor, myofibroma, and other fibromatoses. We present three varied, distinct cases of pediatric lipoblastoma and review the literature on this condition.

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.

Analysis of clinical features of lipoblastoma in children.

OBJECTIVE: A lipoblastoma is pathologically benign but often recurs. Due to its rarity, studies are scarce. The purpose of this study was to investigate the clinical characteristics of lipoblastoma occurring in children and to detect any correlations with the expression of Ki-67. PARTICIPANTS: From 1998 to 2010, 33 patients were diagnosed with lipoblastoma at Seoul National University Children's Hospital. METHODS: Ki-67 immunohistochemistry staining of the tumor tissue was performed. RESULTS: A total of 33 patients (64% males) were enrolled in the study, with a mean age of 28 month. Eleven and 22 lesions were deep and superficial, respectively. Complete excisions were performed for 30 patients, and three underwent incomplete excisions. Two patients who underwent incomplete excision subsequently underwent a second operation due to tumor regrowth, and one patient had a recurrence despite complete excision. There was no statistically significant correlation observed between the tumor size or recurrence and the expression of Ki-67. CONCLUSIONS: Lipoblastoma requires an accurate diagnosis and operative resection to alleviate the symptoms induced by its growth. Incompletely resected tumor may regrow; therefore, complete excision is the treatment of choice. Continuous follow-up is needed to monitor for recurrence of disease, even after a complete excision.

Spinal dumbbell lipoblastoma: a case-based update.

INTRODUCTION: Lipoblastomas are benign tumors that arise from the proliferation of fetal adipose tissue. They are frequently found in the extremities, in the head, and in the neck. Dumbbell conformation (which refers to epidural tumors with extraspinal extension) has been described in only seven lipoblastoma cases so far. CASE REPORT: We describe an 11-month-old patient with a large mediastinal dumbbell lipoblastoma. The mass was excised, but it recurred 1 year later when the MRI showed also multiple pleural lipoblastomatous lesions, thus establishing the diagnosis of lipoblastomatosis. The tumor has been removed with a second surgical procedure. CONCLUSION: Radical excision of lipoblastomas is the gold standard but is not always possible to achieve. Residual lesions can be managed conservatively, on the basis of the benign nature of the tumor and of its potential maturation to normal fat. Recurrence of lipoblastoma appears in 15 % of non-radical excisions but has not yet been described in the form of lipoblastomatosis. A second surgery is indicated if the tumor mass reaches large dimensions, if it increases in size, and if it threatens the functionality of vital organs such as the spinal cord.

[Retroperitoneal lipoblastoma in an infant. A case report]. / Lipoblastoma retroperitoneal en un lactante. Caso clínico.

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.

[Adipocytic tumors]. / Tumeurs adipeuses.

Adipocytic tumors are the most common mesenchymal neoplasms, liposarcoma accounting for approximately 20% of soft tissue sarcomas. The differential diagnosis between benign and malignant tumors is often problematic and represents a significant proportion of consultation cases. The goal of this article is to review liposarcoma subtypes, the main benign adipocytic neoplasms: lipoblastoma, hibernoma, spindle/pleomorphic cell lipoma, chondroid lipoma, as well as non adipocytic neoplasms with a lipomatous component such as lipomatous solitary fibrous tumor, emphasizing on practical differential diagnosis issues, and immunohistochemical and molecular tools allowing their resolution.

Diagnostic utility of molecular and cytogenetic analysis in lipoblastoma: a study of two cases and review of the literature.

AIMS: Lipoblastoma is a benign neoplasm of embryonic white fat tissue that results from the proliferation of primitive adipocytes, in which histological features can be ambiguous. In order to discriminate between lipoblastoma and other lipogenic and lipomatous tumours, we studied chromosomal alterations and protein expression in two cases of lipoblastoma in infants. METHODS AND RESULTS: Standard cytogenetic analysis, fluorescence in-situ hybridization, array comparative genomic hybridization and Western blotting allowed us to demonstrate the presence of chromosome abnormalities involving the 8q11-13 region containing the pleomorphic adenoma gene 1 (PLAG1), which are classically reported in lipoblastoma, and aberrant expression of PLAG1. CONCLUSIONS: This report illustrates two different tumorigenic pathways implicating PLAG1 in lipoblastoma: amplification through multiple copies of a small marker chromosome derived from chromosome 8, and a paracentric inversion of the long arm of chromosome 8. Both these anomalies induced aberrant expression of PLAG1, emphasizing the role of PLAG1 in tumorigenesis. The aberrant expression of PLAG1 protein has been hypothesized, but this is the first report to demonstrate its occurrence in lipoblastoma.