Christiane Baunin

Hypophosphatasia may lead to bone fragility: don’t miss it

Hypophosphatasia is an inheritable disorder characterised by defective bone mineralisation due to the impaired activity of tissue-non-specific alkaline phosphatase (AP). Clinical presentation ranges from stillbirth without mineralised bone to pathological fractures in late adulthood. During childhood, the main manifestations include rickets, growth delay and dental problems. Fractures and bone pain usually characterise the adult form. A 9-year-old girl was referred for repetitive fractures after minimal trauma. She had normal growth, normal sclerae, no rickets and minimal dental abnormalities. Her sister had also presented fractures. The proband, her sister and mother had low total and bone-specific AP levels and E435K mutation in exon 12 of the liver/bone/kidney AP gene. Low AP levels must lead to genetic analysis. Bone fragility and repetitive fractures may be symptoms of hypophosphatasia in childhood, which must not be neglected. Associated factors such as vitamin D or calcium deficiency must be prevented. In conclusion, hypophosphatasia must not be forgotten as an aetiological factor of repetitive fractures or bone pain in children and AP activity should be checked accurately.

Mechanical occlusion of the inferior vena cava: An early complication after repair of pectus excavatum using the Nuss procedure

The Nuss procedure is the most widely used surgical procedure to correct pectus excavatum. Although it is a minimally invasive approach, a number of major early complications, such as heart perforation, have been reported. We describe a 15-year-old boy in whom acute occlusion of the inferior vena cava developed after a Nuss repair. The diagnosis was confirmed by emergency postoperative CT examination, and treatment consisted of immediate removal of the Nuss bar.

Low-dose biplanar radiography can be used in children and adolescents to accurately assess femoral and tibial torsion and greatly reduce irradiation.

PurposeTo evaluate in children the agreement between femoral and tibial torsion measurements obtained with low-dose biplanar radiography (LDBR) and CT, and to study dose reduction ratio between these two techniques both in vitro and in vivo.Materials and methodsThirty children with lower limb torsion abnormalities were included in a prospective study. Biplanar radiographs and CTs were performed for measurements of lower limb torsion on each patient. Values were compared using Bland-Altman plots. Interreader and intrareader agreements were evaluated by intraclass correlation coefficients. Comparative dosimetric study was performed using an ionization chamber in a tissue-equivalent phantom, and with thermoluminescent dosimeters in 5 patients.ResultsAverage differences between CT and LDBR measurements were –0.1° ±1.1 for femoral torsion and –0.7° ±1.4 for tibial torsion. Interreader agreement for LDBR measurements was very good for both femoral torsion (FT) (0.81) and tibial torsion (TT) (0.87). Intrareader agreement was excellent for FT (0.97) and TT (0.89). The ratio between CT scan dose and LDBR dose was 22 in vitro (absorbed dose) and 32 in vivo (skin dose).ConclusionLower limb torsion measurements obtained with LDBR are comparable to CT measurements in children and adolescents, with a considerably reduced radiation dose.Key points• LDBR and CT lower-limb torsion measurements are comparable in children and adolescents.• LDBR considerably reduced radiation dose necessary for lower-limb torsion measurements.• LDBR can be used for evaluation of lower limb-torsion in orthopaediatric patients.

The surgical management and outcome of congenital mediastinal malformations

We reviewed our institutional experience with congenital mediastinal masses and compared the postnatal management and outcome of patients with or without prenatal diagnosis. Between January 1997 and August 2011, 24 patients underwent surgical procedures for congenital mediastinal mass. For eight patients, the mass was detected by prenatal ultrasonography at 27 weeks of gestation (range 22-35). Postnatal management consisted in open surgery for seven patients at a mean age of 9 months (range 1 day-20 months) and sclerotherapy for one lymphangioma at 5 months of life. Sixteen patients had postnatal diagnosis at 137 months (±194) of median age. Eight bronchogenic cysts, seven bronchopulmonary foregut malformations, five teratomas, three lymphangiomas and one haemangioma were operated on. The median age at resection was 28 months (1 day-15 years). There were four emergency procedures and no surgical mortality. The median follow-up was 45 months (3-144). The duration of mechanical ventilation and hospital stay was, respectively, 4.6 h and 7.5 days for antenatal patients and 24.3 h and 14.3 days for postnatal diagnosed patients. Prenatal diagnosis allows early management of congenital mediastinal malformations. Early resection can be performed prior to the occurrence of symptoms ∼1 year of life and is associated with an excellent outcome and less morbidity.

Rapid development of an osteosarcoma after surgical resection of an osteochondroma.

The rapid development of an osteosarcoma, after surgical resection of an osteochondroma, has not been yet reported. We present here the case of a 12-year-old girl that had, in less than 2 months, an osteosarcoma at the initial site of a treated osteochondroma. Comparative Genomic Hybridization analyses showed that the 2 tumors were genetically distinct, suggesting a distant, if any, relationship. The possible implication of a deregulated tissue homeostasis caused by the surgical intervention is discussed. Proangiogenic factors involved in the tissue healing could be the triggering factor favoring tumor angiogenesis and explaining the very rapid progression of the tumor.

Non-contrast-enhanced MR angiography using time-spin labelling inversion pulse technique for detecting crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with surgical findings.

ObjectivesInvestigate the feasibility and evaluate the accuracy of non-contrast-enhanced MR angiography (NC-MRA) using time-spin labelling inversion pulse (time-SLIP)to identify crossing renal vessels (CRVs) in children requiring surgical treatment of ureteropelvic junction (UPJ) obstructionand compare to laparoscopic findings.Materials and methodsNineteen children ranging from 6 to 16 years of age underwent NC-MRA using the time-SLIP technique before surgery. Two independent readers analysed the MRA images. Number of renal arteries and presence or absence of CRVs were identified and compared with surgicalfindings. Image quality was assessed, as well as the presence of CRVs and measurement of renal pelvis diameter. Intra and inter-reader agreement was calculated using Cohen’s kappa coefficient and Bland–Altman plots.ResultsThe overall image quality was fair or good in 88% of cases. NC-MRA demonstrated CRVs at the level of the obstruction in 10 children and no CRV in 9 children. All were confirmed intra-operatively except in one of the nine children. Sensitivity, specificity, NPV, PPV for predicting CRVs were 92%, 100%, 100% and 87.5%, respectively, for both readers.ConclusionNC-MRA is a good alternative to contrast-enhanced MRA and CT scanning for identifying CRVs in children with symptomatic UPJ.Key points• Time-SLIP technique offers acceptable imaging quality for identifying crossing renal vessel.• Time-SLIP technique is easy to apply to the renal MRA examination.• Time-SLIP technique is an alternative to contrast-enhanced MRA and CT scanning.

Pulmonary and intestinal congenital anomalies masquerading as cystic suprarenal masses.

OBJECTIVES The prenatal finding of a cystic suprarenal mass (CSM) presents a wide differential diagnosis. The aim of this study was to present the natural course and outcome of antenatally diagnosed CSMs. METHODS We reviewed the medical records of patients with prenatally detected CSMs that were assessed between January 1998 and December 2011. Retrospective data collection included the age at the time of diagnosis, the size of the mass, and the sonographic evolution of the mass. Surgical treatment was indicated in cases of malignant tumors and symptoms or when size increased. RESULTS The observation period ranged from 1 month to 10 years. The data of 21 patients were analyzed. The median length of follow-up was 32 months (ranging from 2 to 131 months). A total of 13 masses were detected on the left side and 8 on the right side. In 13 patients, the lesions disappeared after a median of 7 months (ranging from 0 to 37 months). Surgery was performed in two neonates: one for a teratoma at 10 days postpartum, and one for a neuroblastoma at 17 days postpartum. Six patients had an extralobar pulmonary sequestration (ELPS), and in four patients, surgical resection was performed at an average of 9.2 months (ranging from 1 to 20 months) postpartum, because of an infection or increase in ELPS size. Histological examination confirmed the pulmonary sequestration. An association with congenital cystic adenomatoid malformation (CCAM) was found in one patient, and ectopic pancreatic tissue was discovered in another patient. Two patients conservatively managed remain under observation. CONCLUSIONS During the neonatal period, the accurate assessment of CSMs is necessary to exclude the presence of malignant tumors. Most patients can be conservatively managed, with close follow-up, including radiological assessment. If the mass persists after 1 year of age, ELPS should be considered as a probable diagnosis, and minimally invasive laparoscopic surgery can be performed, as it provides both definitive diagnosis and treatment.