Lipoblastomatosis: ultrastructure of two cases and relationship to human fetal white adipose tissue

Two cases of lipoblastomatosis were examined by electron microscopy. In each there was a spectrum of adipose cell differentiation from mature adipocytes to undifferentiated mesenchymal cells. The cells had various shapes and were loosely related to one another and to small blood vessels in a stroma containing sparse collagen and proteoglycan granules. Adipocytes and lipoblasts had a discrete basal lamina but this was absent in immature mesenchymal cells, which had prominent intermediate (10-nm) microfilaments and few or no lipid droplets. Neither case had foci resembling brown adipose tissue or hibernoma (large polygonal cells closely apposed to one another and to capillaries with densely packed pleomorphic mitochondria and focal undulating plasmalemmal invaginations). Both the ultrastructure of lipoblastomatosis and its characteristic loose lobular arrangement by light microscopy closely resemble human fetal "white" adipose tissue.     

Pilot study of propranolol premedication to reduce FDG uptake in brown adipose tissue on PET scans of adolescent and young adult oncology patients

Objective: Physiologic uptake of ¹⁸F-fluorodeoxyglucose (FDG) in brown adipose tissue (adipose tissue) of cancer patients may confound interpretation of positron emission tomography (PET) scans. Uptake in adipose tissue occurs in up to half of pediatric oncology patients undergoing PET scans, and is especially common in adolescents. adipose tissue is innervated by the sympathetic nervous system, and beta blockers such as propranolol have shown efficacy in reducing adipose tissue uptake on PET scans done in older adult oncology patients. Participants: Because propranolol may cause hypoglycemia or other side effects in fasting patients, we prospectively assessed the safety of a single dose of 20 mg propranolol in adolescent and young adult oncology patients undergoing FDG-PET imaging. Methods: Ten patients (median age 18 years, range 14–24) received propranolol premedication prior to FDG-PET. Results: No adverse effects or clinically significant changes in serum glucose, heart rate, or blood pressure were observed. Five of the 10 patients had adipose tissue identified on previous PET scans. However, following propranolol administration only, one patient had persistent uptake in adipose tissue. Conclusions: Propranolol was convenient and safe in fasting adolescent and young adult oncology patients undergoing PET scans. Larger studies are warranted to better define the effectiveness of this approach.     

Mechanical-tactile stimulation (MTS) during neonatal stress prevents hyperinsulinemia despite stress-induced adiposity in weanling rat pups

Stress in early life negatively influences growth quality through perturbations in body composition including increased fat mass. At term (40 weeks) preterm infants have greater fat mass and abdominal visceral adipose tissue than term-born infants. Mechanical-tactile stimulation (MTS) attenuates the stress response in preterm infants and rodents. We tested the hypothesis that MTS, administered during an established model of neonatal stress, would decrease stress-driven adiposity and prevent associated metabolic imbalances in rat pups. Pups received one of three treatments from postnatal days 5 to P9: Neonatal Stress (Stress; n = 20) = painful stimulus and hypoxic/hyperoxic challenge during 60 min of maternal separation; MTS (n = 20) = neonatal stress + 10 min of MTS; or Control (n = 20). Body weight, DXA whole body fat mass (g), MRI subcutaneous and visceral adipose tissue, and fasting adiponectin, leptin, glucose, insulin, and corticosterone were measured at weaning (P21). Stress and MTS weight gain (g/d) were accelerated following neonatal stress with greater fat mass, abdominal subcutaneous adipose tissue, serum adiponectin, leptin, and fasting glucose at weaning (P21). Male Stress and MTS pups had greater visceral adipose tissue depot. Male and female Stress pups were hyperinsulinemic. In summary, neonatal stress compromised body composition by increasing fat mass and abdominal subcutaneous adipose tissue depot, and in males, visceral adipose tissue depot. Importantly, MTS prevented hyperinsulinemia despite of stress-induced adiposity. We conclude that MTS during neonatal stress has the potential to minimize metabolic consequences associated with stress-driven perturbations in fat mass and abdominal adipose depots.     

Pre-medication to block [18F]FDG uptake in the brown adipose tissue of pediatric and adolescent patients

Background: Radiopharmaceutical uptake of [¹⁸F]2-deoxy-2-glucose (FDG) in brown adipose tissue is noted on 15–20% of positron emission tomography (PET) scans in children and adolescents. One report suggests that moderate-dose oral diazepam can partly or completely block FDG uptake in brown adipose tissue. Objective: To determine whether [¹⁸F]FDG uptake in brown adipose tissue can be adequately blocked by pre-medication other than moderate-dose oral diazepam. Materials and methods: One hundred and eighteen [¹⁸F]FDG PET body imaging studies were performed in 69 pediatric patients with a variety of solid tumors. The mean age at the time of imaging was 12.9 years (range 1.2–22.6 years), and 33 studies were performed in patients younger than 10 years old. Seventy-six were performed in boys and 42 in girls. Patients were imaged using a dedicated PET camera. Pre-medication was given in 88 studies: 45 received intravenous fentanyl (0.75–1.0 g/kg), 34 received low-dose oral diazepam (0.06 mg/kg) and 9 received moderate-dose oral diazepam (0.10 mg/kg). Thirty patients received no pre-medication, 7 of whom were known to have received opiates for pain during the 12 h before the study. Six body regions in the neck and chest were reviewed for [¹⁸F]FDG uptake in brown adipose tissue. Uptake of FDG in brown fat was visually graded: 0 for no FDG uptake, 1 for low-grade uptake, 2 for moderate uptake, and 3 for intense uptake. Visual grades 2 and 3 were considered to interfere potentially with image interpretation in the neck and chest. Data were analyzed by multivariate regression using a Poisson distribution. Results: [¹⁸F]FDG uptake in brown adipose tissue was most often seen in the lateral neck region and superior and lateral to the lungs (in 36 and 39 studies, respectively). Uptake was also seen near the costovertebral junctions (15 studies), in the superior and central neck in 7 studies and in the anterior mediastinum in 2. Brown adipose tissue uptake was thought to interfere potentially with image interpretation (visual grades 2 and 3) in 19 studies—in 6 of 23 (26.1%) studies after no pre-medication and no opiates for pain, in 10 of 34 (29.4%) after low-dose oral diazepam, in 0 of 9 (0%) after moderate-dose oral diazepam, in 3 of 45 (6.7%) after intravenous fentanyl, and in 0 of 7 (0%) after opiates prescribed for pain. Intravenous fentanyl reduced the grade of brown adipose tissue compared to no drug (P=0.0039) and low-dose diazepam (P=0.0024). Low-dose diazepam had no effect when compared to no drug (P=0.984). There were inadequate data for statistical testing of moderate-dose valium and opiates prescribed for pain. Children younger than 10 years had lower uptake grades (P=0.019) than those older than 10 years. Summary: The frequency of interfering [¹⁸F]FDG uptake in brown adipose tissue is reduced by intravenous fentanyl pre-medication, which appears to be an effective alternative to the existing standard pre-medication, moderate-dose oral diazepam.     

Increase in visceral adipose tissue and subcutaneous adipose tissue thickness in children with acute pancreatitis. A case-control study

AimThe aim of this study was to investigate the relationship between the development of acute pancreatitis in children and their body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) thickness.MethodThis was a case-control study carried out in a tertiary hospital between October and November 2019. The diagnosis of acute pancreatitis was based on the presence of at least two of three criteria of the International Study Group of Pediatric Pancreatitis (INSPPIRE) guidelines. AC, VAT, and SAT measurements of patients and controls were performed by using a three-dimensional workstation (Aquarius 3D Workstation, TeraRecon Inc., San Mateo, Calif., USA) through cross sections of the L2 vertebra level after examining previous abdominal computerized tomography (CT) records.ResultsA total of 25 patients diagnosed with acute and acute recurrent pancreatitis who underwent abdominal CT were included in the study and 38 healthy, sex- and age-matched children formed the control group. There were no differences between the patients and healthy children in terms of age, sex and BMI-for-age z-scores. Besides, measurements of WC, SAT, and VAT thickness were found to be higher in the patient group (P = 0.007, P = 0.021, P = 0.016, respectively).ConclusionIn this study, WC, VAT, and SAT were found to be thicker in children with acute pancreatitis compared with healthy children without any difference in BMI. Further studies are needed to clarify whether adipose tissue thickness is an etiological cause or a secondary finding in patients with acute pancreatitis.     

<Superscript>123</Superscript>I-MIBG uptake in the neck and shoulders of a neuroblastoma patient: damage to sympathetic innervation blocks uptake in brown adipose tissue

Uptake of ¹²³I-MIBG in the neck and shoulders has recently been shown to be caused by uptake in brown adipose tissue. Unilateral absence of ¹²³I-MIBG uptake in brown adipose tissue ipsilateral to the clinical findings of a post-surgical Horners syndrome suggests that, in humans, as in the animal model, uptake in brown adipose tissue is mediated by the sympathetic nervous system. This case further elucidates the mechanism of radiopharmaceutical uptake in brown adipose tissue and also suggests possible models for future studies of the physiology and pharmacology of brown adipose tissue.     

Fatty Acid Composition of Subcutaneous Adipose Tissue in Mother-Infant Pairs

ABSTRACT. The fatty acid composition of microsamples from 10 AGA term, 8 SGA term, 7 AGA preterm and 4 SGA preterm, 2–4 day old infants and their mothers were analyzed. In AGA preterm newborns the mean percent of palmitic and stearic acid was lower and the mean percent of linoleic acid was higher than in AGA term infants indicating that there is an increase in fatty acids derived by synthesis from glucose throughout gestation. SGA infants had relative amounts of palmitic and stearic acid similar to what was found in AGA term infants. This indicates that the enzymes involved in synthesis of fatty acids from glucose are intact in intrauterine growth retardation (IUGR). The absolute amount of adipose tissue and fatty acids, however, is smaller in SGA infants due to a reduced availability of glucose in IUGR gestation. No differences were found in the fatty acid composition of subcutaneous adipose tissue from the mothers in the 4 groups. All mothers had a lower mean percent of palmitic and stearic acid and a higher mean percent of oleic and linoleic acid than their infants, ensuring a transplacental gradient to the fetus of this latter essential fatty acid. The fatty acid composition of plasma free fatty acids generally reflected the composition of the subcutaneous adipose tissue in the infants.     

Radiological–pathological correlation in lipoblastoma and lipoblastomatosis

Background Lipoblastoma and lipoblastomatosis are uncommon benign mesenchymal lesions that predominantly occur in infancy and early childhood.Objective To evaluate the imaging and histological features of lipoblastoma and lipoblastomatosis.Materials and methods Retrospective review of the radiological and pathological findings in children with lipoblastoma and lipoblastomatosis treated at a single centre between 1997 and 2004.Results Eight children (median age 18 months) had undergone imaging and surgery at our institution. An infiltrative growth pattern was identified at imaging in two children with lipoblastomatosis, and a well-defined mass in six children with lipoblastoma. In all patients, imaging showed a lesion composed mostly, but not entirely, of fat. There were no recurrences at follow-up of between 1 and 91 months.Conclusion In infancy and early childhood, the identification of a tumour composed mostly of fat should suggest the diagnosis of lipoblastoma or lipoblastomatosis.     

Undifferentiated (“Embryonal”) Sarcoma of the Liver: Ultrastructure of a Case Presenting as a Primary Intracardiac Tumor

We report the ultrastructure of an undifferentiated (“embryonal”) sarcoma of the liver that presented as a right-sided intracardiac tumor in an 8-year-old boy. The patient eventually died because of repeated embolization of tumor to the lungs. At autopsy the hepatic primary was composed of primitive mesenchymal cells with occasional small cysts and ducts lined by benign-appearing epithelium. Electron microscopy of the mesenchymal cells indicated a limited capacity for pluripotential differentiation along fibroblastic, lipoblastic, and even myogenous lines. Epithelial elements closely resembled those lining normal bile aucts but contained increased fibrillar material with haphazard orientation. The histogenesis of this rare hepatic tumor is still unknown, but the occurrence of both epithelial and frankly sarcomatous elements within the primary tumor again raises the possibility of malignant transformation within a pre-existing mesenchymal hamartoma.     

Threshold values of visceral fat and waist girth in Japanese obese children

BACKGROUND: In order to define the diagnostic criteria for visceral adipose tissue (VAT) accumulation and abdominal obesity in Japanese youths, a cross-sectional, multicenter study was conducted. METHODS: Subjects were 194 boys and 96 girls ranging in age from 6 to 15 years. Obese youths were classified according to the occurrence of abnormal values in serum triglyceride, alanine aminotransferase or insulin level. A threshold value of each criterion was calculated, using the analysis of receiver operating characteristic (ROC) curve. The areas of total abdominal adipose tissue (AT), VAT and subcutaneous adipose tissue (SAT) were estimated by single slice computed tomography at the level of umbilicus. RESULTS: VAT area was greater in boys than it was in girls. The critical values for VAT area and waist circumference in all subjects were 54.8 cm2 and 83.5 cm, respectively. The values for the area under the ROC curves were VAT area > total AT area > waist circumference > SAT area > percentage overweight > percentage body fat. The sensitivity and specificity for VAT area were 90.5 and 79.5%, respectively. Those for waist circumference were high enough (> 70%) for clinical use. In the linear regression analysis assigning VAT area as an independent variable and waist circumference as a dependent variable, the expected value for the waist circumference was 82 cm. CONCLUSION: In Japanese obese youths ranging in age from 6 to 15 years, the diagnostic criteria for the waist circumference was 82 cm, and that for VAT area was 55 cm2.     

TSG-6基因在脂肪组织中的表达及其与肥胖的关系

目的：鉴定TSG－6基因在正常和肥胖儿童脂肪组织中的表达，探讨该基因与肥胖的关系。方法：采用RT－PCR技术检测正常和肥胖儿童皮下脂肪组织中TSG－6基因的表达水平，并测序鉴定。结果：TSG－6基因表达于儿童的脂肪组织，且肥胖组患儿皮下脂肪组织中TSG－6基因的表达水平显著高于正常对照组。结论：TSG－6基因是一个新的与肥胖发生相关基因，可能与肿瘤坏死因子－α（TNF－α）、白细胞介素1（IL－1）共同调节肥胖的发生。     

Intrabdominal fat is related to metabolic risk factors in Hispanic Americans, African Americans and in girls

Aim:  This study aimed to test the association of individual adipose depots on cardiometabolic outcomes, whether the association varied by depot and if the associations differed by race/ethnicity or gender in early pubertal children.
Methods:  Three hundred and twenty children (53% male) aged 7–12 years self-identified as African American (AA; n = 114), European American (EA; n = 120) or Hispanic American (HA; n = 86) participated. Insulin dynamics were assessed by intravenous glucose tolerance test; body composition with DXA; fat distribution with CT.
Results:  AA had the least fat in each depot and HA had the most. Fat accumulation negatively impacted cardiometabolic outcomes independent of race/ethnicity or gender. AA and females were reproductively more mature. In AA and HA, each measure of adiposity influenced the insulin sensitivity index (S_I), whereas intra-abdominal adipose tissue (IAAT) did not contribute to S_I in EA. IAAT was positively associated with blood pressure in AA only. In females, adiposity adversely influenced cardiometabolic outcomes such that total fat mass, IAAT and/or SAAT was inversely associated with S_I, and positively associated with blood pressure and fasting insulin.
Conclusion:  IAAT is uniquely related to metabolic risk factors in Hispanic Americans, African Americans and girls, suggesting that either the threshold for adverse effects of IAAT is lower, or the IAAT metabolism differs in these groups.     

Lipoblastoma and lipoblastomatosis in children.

Lipoblastoma and lipoblastomatosis are rare mesenchymal benign tumors of embryonal white fat. They are found primarily in children less than 5 years of age. This tumor presents in two forms: a localized well-circumscribed lesion (lipoblastoma), or a multicentric type (lipoblastomatosis). The authors presents three cases, two of them with a buttock lesion, the last with a paravertebral one. It is recommended a complete but conservative excision of the tumor because there is a natural tendency to involution, although in the first year of life a local reexcision for recurrence is sometimes described.     

Aerobic fitness and visceral adipose tissue in children

AIM: To determine the relationship between aerobic fitness (peak VO2) and the volume of visceral adipose tissue (VAT) in children. METHODS: Participants were 30 males (13.7+/-0.5 y) and 22 females (13.5+/-0.5 y). Peak VO2 was determined using a continuous, incremental treadmill protocol to exhaustion. Abdominal VAT volume was measured by magnetic resonance imaging using multiple slices from vertebral levels L1-L5. Subcutaneous body fat measure was calculated as the sum of seven skinfolds (sigma7SKF). RESULTS: Females had significantly (p < or = 0.05) more VAT than males (1035+/-717.3 vs 678.6+/-361.5 cm3); however, male peak VO2 was higher (215+/-34 vs 182+/-20 ml/kg(0.61)/min). VAT was significantly (p < or = 0.05) negatively correlated with peak VO2 in both males (r = - 0.43) and females (r = - 0.45). Subcutaneous body fatness was significantly correlated with VAT in both males (r = 0.74) and females (r = 0.72), and was the single strongest determinant of VAT. CONCLUSION: Aerobic fitness is significantly inversely related to VAT, but subcutaneous body fatness is the single strongest determinant of VAT in children aged 13-14 y.     

Giant abdomino-pelvic adipose tumors of childhood

Adipose tumors are rare in pediatric age and are commonly represented by benign forms: lipoma and lipoblastoma/lipoblastomatosis. Generally localized in subcutaneous tissue of the trunk and extremities, they can exceptionally occur as giant intra-peritoneal or pelvic masses. These tumors could reach considerable size prior to diagnosis since they are asymptomatic. The authors report a case series of three giant abdomino-pelvic adipose tumors.     

Lipid content and fatty acid pattern in the subcutaneous adipose tissue during childhood —a function of age and nutrition

The lipid content and the fatty acid pattern were analysed in the abdominal subcutaneous adipose tissue of 241 children aged 2 months to 12 years. The lipid content was found between 63 and 71%.During childhood the portion of saturated fatty acids in the subcutaneous adipose tissue decreases significantly; the unsaturated fatty acid portion, however, increases accordingly. This change in the fatty acid pattern concerning the saturated fatty acids is mainly determined by myristic, palmitic and stearic acids, concerning the unsaturated fatty acids it is determined by palmitoleic, oleic and linoleic acids. The changes during childhood in the percentage of the single fatty acids are described in detail.In addition to the age-dependent development of the fatty acid pattern in the subcutaneous adipose tissue a dependence upon diet will probably exist for stearic, lauric and linoleic acids.The investigations were supported by the Ministerium für Wissenschaft und Forschung — Landesamt für Forschung — des Landes Nordrhein-Westfalen, Federal Republic of Germany     

肥胖幼鼠脂肪组织vaspin与胰岛素敏感性的关系

目的：探讨幼年肥胖Sprague-Dawlely（SD）大鼠脂肪组织vaspin含量与胰岛素敏感性的关系。方法：断乳3周SD大鼠24只,随机分为高脂饮食组和普通饮食组,每组12只。成功建模后,测定各组体重、腹围。禁食12 h 后取内眦静脉血测定空腹血糖（FPG）、空腹胰岛素（FINS）;再腹腔注射50%葡萄糖（2 g/kg）,于注射后60 min、120 min再次取内眦静脉血测定各时间点血糖（BG）及胰岛素（INS）。幼鼠处死后将内脏脂肪组织称重。酶联免疫吸附法测定各组幼鼠内脏脂肪组织中vaspin的含量,并对vaspin表达量与各体格测量指标及胰岛素敏感性评价指标进行相关性分析。结果：高脂饮食组大鼠的体重、腹围、内脏脂肪重量、FPG、FINS、120 min INS、vaspin、胰岛素抵抗指数（HOMA-IR）、胰岛素分泌指数（HOMA-β）均高于普通饮食组（P<0.05）,高脂饮食组胰岛素敏感指数（ISI）明显低于普通饮食组（P<0.01）。Vaspin含量与肝脏重量、内脏脂肪重量、腹围、120 min INS、FPG、FINS、HOMA-IR、HOMA-β呈正相关（P<0.05）,而与ISI呈负相关（P<0.05）。结论：幼年肥胖SD大鼠胰岛素抵抗状态与vaspin高水平表达有关,推测vaspin是一种增加胰岛素敏感性、促进胰岛β细胞分泌胰岛素和改善糖耐量的脂肪细胞因子,可能参与了胰岛素抵抗、糖代谢紊乱状态的形成。     

Size of adipose cells in infancy.

Seventy-three samples of adipose tissue from 59 infants, aged from 25 weeks' gestation to 18 months of age, were obtained at necropsy, or at operations, or by needle biopsy. Adipose cell size was measured by microscopy. During fetal life the mean cell diameter increases from about 40 mum at 25 weeks' gestation to 50-80 mum at term. Adipose cells from the buttocks are larger than those from abdominal wall. After birth, adipose cell size continues to increase so that by 3 months the mean cell diameter is about 90 mum. Observations made on infants that had been born preterm showed that the growth of adipose cells proceeds at the same rate whether development in intrauterine or extrauterine.     

Relation of subepicardial adipose tissue thickness and clinical and metabolic parameters in obese prepubertal children

HızlıŞ, Özdemir O, Abacı A, Razi CH and Kabakuş N. Relation of subepicardial adipose tissue thickness and clinical and metabolic parameters in obese prepubertal children. Background: The measurement of subepicardial adipose tissue thickness (SATT) has been found to be related to insulin resistance (IR) in adults. Until now, the association between SATT and IR has not been evaluated in obese prepubertal children. We aimed to determine the relation of SATT with clinical anthropometric and metabolic parameters and to provide cutoff value of SATT associated with IR in obese prepubertal children. Methods: Fifty‐two obese (mean age: 9.5 ± 1.6 years, 29 female) and 31 lean prepubertal age‐ and gender‐matched subjects (mean age: 9.2 ± 1.4 years, 12 female) were evaluated by echocardiography. SATT was measured by transthoracic echocardiography. Results: SATT (6.54 ± 1.38 mm) and homeostatic model assessment‐insulin resistance (HOMA‐IR) (3.2 ± 2) values of obese prepubertal subjects were significantly higher than those of the lean subjects (3.72 ± 0.57 mm and 1.6 ± 1) in the control group (both p < 0.001). Bivariate correlation analysis showed significant correlation between SATT, age, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist‐to‐hip ratio (WHR), mid‐arm circumference (MAC), triceps skin fold (TSF) thickness, insulin, and HOMA‐IR (r = 0.547, r = 0.524, r = 0.543, r = 0.431, r = 0.289, r = 0.402, r = 0.400, r = 0.328, r = 0.289, p < 0.05, respectively). As an optimal cutoff point, an SATT of 4.33 mm determined IR with 93.3% sensitivity and 51% specificity. Conclusions: Our study on obese prepubertal children showed that SATT was significantly correlated with age, BMI, WC, HC, MAC, TSF, insulin, and HOMA‐IR.     

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.