[Cardiac Magnetic Resonance in long term follow-up of Tetralogy of Fallot]. / Resonancia magnética cardíaca en el seguimiento alejado de pacientes con tetralogía de Fallot.

INTRODUCTION: Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart disease. Pulmonary regurgitation (PR) and right ventricle (RV) enlargement and dysfunction are the most common long-term complications. Cardiac magnetic resonance (CMR) is the gold standard for RV evaluation. OBJECTIVE: To analyze CMR results in the follow-up of TOF patients. PATIENTS AND METHOD: All CMR performed between 2007 and 2012 in TOF patients with transannular patch (TAP) repair or infundibular widening, and without pulmonary valve replacement (PVR) were included. Pulmonary regurgitant fraction (PRF), ventricular end-diastolic (EDV) and end-systolic volume (ESV), and ejection fraction (EF) were examined. RESULTS: 122 CMR were performed in 114 patients. Average age at CMR was 15.4±7.4 years. 53.3% of them presented severe PR (> 40%). RVEDV was 157.3 ± 38.6 ml/m2, RVESV was 85.3 ± 27 ml/m2 and RVEF was 46.4 ± 7.1%. RVEDV was > 150 ml/ m2 in 48.4% and > 170 ml/m2 in 32.8% of patients. Patients with TAP showed larger RV volumes compared with those with infundibular widening. RVEDV > 170 ml/m2 showed worse RVEF that those with lower RVEDV (47.9 ± 7% vs 43.2 ± 6.4%, p < 0.01). CONCLUSION: Almost half of the pa tients showed significant RV enlargement, demonstrating that the indication of CMR is late in their follow-up. TAP was associated with higher RVEDV and RVESV, but no worse RVEF.

Ischaemic stroke in children with cardiopathy: An epidemiological study. / Ictus isquémico en niños con cardiopatía: estudio epidemiológico.

INTRODUCTION: Ischaemic stroke is rare during childhood. Congenital and acquired heart diseases are one of the most important risk factors for arterial ischaemic stroke (AIS) in children. PATIENTS AND METHODS: We conducted a retrospective study of all children with AIS and heart disease diagnosed between 2000 and 2014. RESULTS: We included 74 children with heart disease who were eligible for inclusion. 60% were boys with a mean stroke age of 11 months. 20% of the patients died during the study period. 90% of the patients had a congenital heart disease, while cyanotic heart disease was identified in 60%. Hypoplastic left heart syndrome was the most frequent heart disease. In 70% of patients AIS was directly associated with heart surgery, catheterisation or ventricular assist devices. Most patients with AIS were in the hospital. Seizures and motor deficit were the most frequent symptoms. Most patient diagnoses were confirmed by brain CT. The AIS consisted of multiple infarcts in 33% of the cases, affected both hemispheres in 27%, and involved the anterior and posterior cerebral circulation in 10%. CONCLUSIONS: Arterial ischaemic strokes were mainly associated with complex congenital heart diseases, and heart procedures and surgery (catheterisation). AIS presented when patients were in-hospital and most of the patients were diagnosed in the first 24hours.

Invasive alien species water hyacinth Eichhornia crassipes as abode for macroinvertebrates in hypertrophic Ramsar Site, Lake Xochimilco, Mexico.

This paper presents information on the density, diversity and functional feeding groups of macroinvertebrate assemblages associated with water hyacinth in Antiguo Canal Cuemanco, part of Lake Xochimilco in Mexico City. Rare (low frequency and density) and dominant (high frequency and density) taxa prevailed in the assemblages, with the most predominant being Hyalella azteca, Chironomus plumosus and Ischnura denticollis. Nonmetric Multidimensional Scaling confirmed two climatic seasons: warm-rainy and cold-dry; the former with the highest diversity and density of taxa. Canonical Correspondence Analysis showed that conductivity, nitrates and turbidity explained the density variations of taxa. Antiguo Canal Cuemanco waters are spatially homogeneous with the characteristics of hypertrophic shallow lakes, inhabited by scrapers and gathering-collectors. The species found were tolerant to organic pollution.

Association between neuroimaging findings and neurological sequelae in patients with congenital cytomegalovirus infection.

BACKGROUND: Congenital cytomegalovirus (CMV) infection is an important cause of disability. There is little evidence on the prognostic value of lesions identified in neuroimaging studies. AIM: The study aimed to assess the severity of lesions detected with brain MRI and transfontanellar ultrasound and their relationship with long-term neurological deficits. PATIENTS AND METHODS: We performed a retrospective, analytical, observational study of 36 patients with congenital CMV infection. Neuroimaging studies were reviewed and classified according to the modified Noyola' scale. Imaging findings were compared with neurological alterations in the patients' most recent follow-up evaluation at the paediatric neurology department. RESULTS: Thirty-six patients were studied (transfontanellar ultrasound: 30; brain MRI: 29). Twenty of 30 patients showed ultrasound abnormalities; of these, 11 showed alterations on brain MR images (P = .04) and 10 had neurological impairment (P = .008). Transfontanellar ultrasound had a sensitivity of 83.3%, 90% CI: 58-100 and a specificity of 44.4%, 90% CI: 18.7-70.2 for predicting neurological sequelae. Brain MRI displayed abnormalities in 20 of 29 patients, of whom 16 had neurological impairment (P < .001). MRI had a sensitivity of 94%, 95% CI: 80-100 and a specificity of 66.6%, 95% CI: 36-97.5 for predicting neurological sequelae. Modified Noyola' scale values > 2 were correlated with psychomotor retardation (P < .001). CONCLUSIONS: Our findings validate previous studies reporting a statistical significant correlation between the extension of neuroimaging lesions and severity of neurological deficits.

Association between neuroimaging findings and neurological sequelae in patients with congenital cytomegalovirus infection. / Asociación entre neuroimagen y secuelas neurológicas en pacientes con infección congénita por citomegalovirus.

BACKGROUND: Congenital cytomegalovirus (CMV) infection is an important cause of disability. There is little evidence on the prognostic value of lesions identified in neuroimaging studies. AIM: The study aimed to assess the severity of lesions detected with brain MRI and transfontanellar ultrasound and their relationship with long-term neurological deficits. PATIENTS AND METHODS: We performed a retrospective, analytical, observational study of 36 patients with congenital CMV infection. Neuroimaging studies were reviewed and classified according to the modified Noyola' scale. Imaging findings were compared with neurological alterations in the patients' most recent follow-up evaluation at the paediatric neurology department. RESULTS: Thirty-six patients were studied (transfontanellar ultrasound: 30; brain MRI: 29). Twenty of 30 patients showed ultrasound abnormalities; of these, 11 showed alterations on brain MR images (P=.04) and 10 had neurological impairment (P=.008). Transfontanellar ultrasound had a sensitivity of 83.3%, 90% CI: 58-100 and a specificity of 44.4%, 90% CI: 18.7-70.2 for predicting neurological sequelae. Brain MRI displayed abnormalities in 20 of 29 patients, of whom 16 had neurological impairment (P<.001). MRI had a sensitivity of 94%, 95% CI: 80-100 and a specificity of 66.6%, 95% CI: 36-97.5 for predicting neurological sequelae. Modified Noyola' scale values >2 were correlated with psychomotor retardation (P<.001). CONCLUSIONS: Our findings validate previous studies reporting a statistical significant correlation between the extension of neuroimaging lesions and severity of neurological deficits.

Astroblastoma. Case report, review of the literature, and analysis of treatment strategies.

Astroblastoma, a unique glial tumor, has been described in the literature in case reports and small series. Its rarity has prevented evidenced-based treatment stratification. An 8-year-old boy presented with signs and symptoms of raised intracranial pressure. Imaging studies of the brain demonstrated a large heterogeneously enhancing solid mass in the left frontal lobe with punctate calcifications and cystic components that created subfalcine and uncal herniation. After tumor resection, histological diagnosis revealed a high-grade cerebral astroblastoma. The child's postoperative recovery was complicated by hydrocephalus that necessitated placement of a ventriculoperitoneal shunt. Fifty-four months after undergoing gross total resection and adjuvant radiation therapy, the patient, now 12-years-old, remains tumor free and neurologically stable. Chemotherapy was reserved in the event of tumor recurrence. Since the first description of astroblastoma, its histopathological and clinical features have been debated. We review the histology, immunohistochemistry, and cytogenetics of astroblastoma as well as examine the current literature and treatment strategies for the management of both low and high-grade tumors. Continued clinical studies and longer patient follow-up with a tumor based registry would further clarify optimal treatment for this rare tumor.

Efectos de las medidas de restricción sobre la actividad física y conducta sedentaria de niños, niñas y adolescentes durante la pandemia por COVID-19: revisión sistemática / Effects of restriction measures on physical activity and sedentary behavior of children and adolescents during COVID-19 pandemic: a systematic review

Introducción: La pandemia por COVID-19 obligó a los gobiernos a implementar medidas de restricción social para proteger la salud de la población, afectando la calidad de vida de las personas, especialmente en grupos vulnerables como los niños, niñas y adolescentes (NNA). El objetivo de esta revisión sistemática (RS) fue evaluar el efecto de las medidas de restricción sobre la actividad física (AF) y conducta sedentaria (CS) de los NNA. Adicionalmente, se exploraron posibles factores determinantes de estos cambios. Métodos: Se realizó una RS, utilizando tres bases de datos. Se incluyeron estudios observacionales en donde se hubiera analizado la AF y CS de los participantes, utilizando cualquier método de evaluación. Dos investigadores analizaron los estudios, extrajeron los datos y evaluaron la calidad metodológica de los artículos primarios. El metaanálisis se realizó utilizando el modelo de efectos aleatorios, considerando un valor p < 0,05 como estadísticamente significativo. Resultados: Se incluyeron 19 artículos, con una muestra total de 15.095 NNA. La mayoría de los estudios reveló una reducción de la AF y un incremento de la CS en los sujetos, durante los confinamientos por COVID-19. El metaanálisis mostró una caída en la AF total, la AF moderada a vigorosa y un incremento del tiempo de sedentarismo. Diversos factores biodemográficos, familiares y ambientales exacerbaron las variaciones en la AF y la CS de los NNA. Conclusión: Las medidas de restricción aplicadas durante pandemia por COVID-19 redujo la AF e incrementó la CS de los NNA. Factores biodemográficos, familiares y ambientales determinaron estas variaciones.

Introduction: The COVID-19 pandemic forced governments to implement social restriction measures to protect the health of the population, affecting the quality of life of people, especially in vulnerable groups, such as children and adolescents (CA). The objective of this systematic review (SR) was to evaluate the effect of restriction measures on physical activity (PA) and sedentary behavior (SB) of CA. Additionally, possible determining factors of these changes were explored. Methods: An SR was carried out, using three databases. Observational studies were included in which the PA and SB of the participants were analyzed, using any evaluation method. Two investigators analyzed the studies, extracted data, and assessed the methodological quality of the primary articles. The meta-analysis was performed using the random effects model, considering a value of p < 0.05 as statistically significant. Results: 19 articles were included, with a total sample of 15,095 subjects. Most studies revealed a reduction in PA and an increase in SB in subjects during COVID-19 lockdowns. The meta-analysis showed a drop in total PA, moderate to vigorous PA, and an increase in sedentary time. Various biodemographic, family and environmental factors exacerbated the variations in the PA and SB of the CA. Conclusion: The restriction measures applied during the COVID-19 pandemic reduced the PA and increased the SB of the CA. Biodemographic, family and environmental factors determined these variations.

Inhibition of Wilms' tumor growth by intramuscular administration of tissue inhibitor of metalloproteinases-4 plasmid DNA.

Extracellular matrix (ECM) degrading matrix metalloproteinases (MMPs) lead to ECM turnover, a key event in cancer growth and progression. The tissue inhibitors of matrix metalloproteinases (TIMPs) limit the activity of MMPs, which suggests their use for cancer gene therapy. Here we report that systemic administration of naked TIMP-4 DNA significantly inhibited Wilms' tumor growth in nude mice. TIMP-4, whose expression was lost in Wilms' tumor, inhibited the growth of G401 Wilms' tumor cells at a concentration lower than those required for MMP inhibition. This inhibition was associated with internalization of exogenous recombinant TIMP-4. Electroporation-mediated intramuscular injection of TIMP-4 expression plasmid resulted in sustained plasma TIMP-4 levels and significant tumor suppression. Our data demonstrate a tumor suppressive effect of TIMP-4 against Wilms' tumor and the potential utility of intramuscular delivery of TIMP gene for treatment of kidney derived cancers.

Nephrotoxicity of allopurinol is enhanced in experimental hypertension.

Hyperuricemia is present in 20-40% of pediatric and adult patients with essential hypertension. This metabolic abnormality may represent an additional risk factor for the development of cardiovascular disease. Therefore, we performed the following studies to determine 1) whether hyperuricemia is more prevalent in the spontaneously hypertensive rat (SHR) and 2) whether allopurinol treatment has a beneficial effect on the development of hypertension in this strain, based on its capacity to lower the serum uric acid concentration and to act as an antioxidant agent. SHR and control Wistar-Kyoto (WKY) rats were assigned to two groups, one given tap water to drink and the other provided water containing allopurinol (400 mg/l) to furnish an approximate daily dose equal to 100 mg/kg body wt. This treatment was maintained for 15 weeks. The serum uric acid levels were similar in untreated SHR and WKY rats (1.85 +/- 0.10 versus 1.66 +/- 0.14 mg/dl; p = 0.28). In the control WKY rat strain, allopurinol therapy did not adversely affect weight gain or hematocrit and did not cause an increase in mortality. It resulted in a moderate decrement in kidney function (creatinine clearance: allopurinol-treated group 0.32 +/- 0.09 versus control group 0.46 +/- 0.04 ml/min/100 g body wt, in conjunction with mild-to-moderate tubulointerstitial inflammation (allopurinol-treated group 0.9 +/- 0.4 versus control group 0).(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis-B-associated glomerulonephritis: pathology, pathogenesis, and clinical course.

Hepatitis-B-associated glomerulonephritis (HBGN) is a distinct entity occurring frequently in hepatitis-B-prevalent areas of the world. The disease affects both adults and children who are chronic hepatitis-B-virus (HBV) carriers with or without a history of overt liver disease. The diagnosis is established by serologic evidence of HBV antigens/antibodies, presence of an immune complex glomerulonephritis, immunohistochemical localization of 1 or more HBV antigens, and pertinent clinical history, when available. In this study we present clinicopathologic and follow-up findings in 12 patients (7 children, 5 adults) with hepatitis-B-associated glomerulonephritis. Twelve patients provided 15 renal biopsies and 1 specimen of kidney tissue, obtained at autopsy; these were examined by light microscopy, electron microscopy, and immunohistochemical methods. Membranous glomerulonephritis (MGN) with or without mesangial proliferation was noted in 7 biopsies, mesangiocapillary (membranoproliferative) glomerulonephritis (MCGN) in 5 biopsies, and proliferative glomerulonephritis with or without membranous changes in 2 biopsies. Tubulointerstitial changes were minimal except in 3 adults, in whom they were attributable to arterionephrosclerosis. Ultrastructural findings included the presence of considerable amounts of focal or diffuse granular electron-dense deposits in the glomeruli, in the subepithelial, subendothelial, and mesangial locations, occasionally destroying or replacing the lamina densa of the basement membrane. Variable mesangial proliferation was also observed, with interposition, with focal irregular reduplication of the basement membranes and rare clusters of spherical particles, probably representing viral particles in the deposits. In addition, granular deposits along tubular basement membranes were seen in 1 case. The glomerular deposits stained for 2 or more immunoglobulins, the predominant one being IgG, and variably also for complement components (C3, C4 and C1q). Hepatitis B viral antigens (HBsAg, HBcAg, HBeAg) were demonstrated using acid elution techniques in the deposits in all biopsies where frozen tissue was available, singly or in a variety of combinations and intensities. There were deposits of IgG, C3, C1q, and HBsAg along the tubular basement membranes in 1 case. Follow-up biopsies in 2 cases, 2 and 5 years apart, showed a transformation from a diffuse MGN to MCGN with segmental membranous features. Follow-up biopsy after 3 years in the third patient, who went into clinical remission, revealed partially resolving glomerular lesions. Renal lesions secondary to chronic liver disease, parasitic diseases, certain tropical nephropathies, and lupus nephritis are some of the diseases that may morphologically resemble HBGN. Recognition and differentiation of HBGN from other entities may have significant prognostic and therapeutic implications.(ABSTRACT TRUNCATED AT 400 WORDS)

Kearns-Sayre syndrome presenting as renal tubular acidosis.

Renal tubular acidosis and tetany were the 1st manifestations of Kearns-Sayre syndrome in a 5-year-old child. Subsequently, he developed progressive external ophthalmoplegia, ptosis, retinopathy, heart block, and endocrinopathy. There was a 7.5-kb deletion of mitochondrial DNA documented in muscle, kidney, skin fibroblasts, and leukocytes, providing evidence for a multisystem mitochondrial cytopathy.

Epstein-Barr virus-associated polymorphic B-cell lymphoproliferative disorders in the lungs of children with AIDS: a report of two cases.

Patients infected with HIV experience a spectrum of lymphoproliferative disorders, including generalized reactive lymphadenopathy to atypical lymphoproliferative lesions and lymphomas. Polymorphic B-cell lymphoproliferative disorders are rare and not well documented. We studied lung lesions from two children infected with HIV: an atypical polymorphic B-cell hyperplasia in a 14-year-old boy and a malignant polymorphic B-cell lymphoma in a 21-month-old girl. Morphologically, both lung lesions revealed similar polymorphic lymphoid infiltrations with numerous mitoses in case 1 and extensive necrosis and architectural distortion in case 2. Immunophenotypic examination showed no predominance of kappa or lambda light chain in case 1 and a predominance of kappa light chain in case 2. Genotypic analysis demonstrated an absence of immunoglobulin and T-cell receptor gene rearrangements in case 1 and the presence of biallelic immunoglobulin heavy chain rearrangement and a single clonal Epstein-Barr virus (EBV) in case 2. The clinical course was indolent in case 1 and aggressive in case 2. The clinicopathologic features were similar to those of posttransplantation lymphoproliferative disorders suggesting that these lung lesions might represent an immunosuppression-related spectrum of benign to malignant diseases. EBV infection may play a role in the pathogenesis of these lesions. This study highlights the importance of the molecular characterization of AIDS-associated lymphoproliferative disorders in children in establishing a definitive diagnosis.

Chondroid chordoma. Electron-microscopic study of two cases.

Chondroid chordoma is an unusual tumor composed of an admixture of chondromatous and chordomatous tissue usually located in the spheno-occipital region. This tumor shares many of the clinical and histologic features of classic chordoma and chondrosarcoma and has been shown to have a better prognosis than either of these lesions. To the best of our knowledge, no ultrastructural studies have been performed in the 26 cases of chondroid chordoma published previously. We document the ultrastructural features of two examples of chondroid chordoma. Certain features such as prominent and dilated rough endoplasmic reticulum, intracytoplasmic glycogen aggregates, and abundant fibrillogranular matrix are common to chordoma, chondrosarcoma, and chondroid chordoma. The presence of well-formed tonofilament desmosome complexes as well as complexes composed of alternating profiles of rough endoplasmic reticulum and mitochondria were seen only in chordoma and chondroid chordoma, but not in cartilaginous tumors. Of particular interest was the finding of crystalline, tubular structures within the rough endoplasmic reticulum of both cases of chondroid chordoma, a finding not described previously. The distinction of chondroid chordoma from classical chordoma is said to be a difficult one at the light-microscopic level, and we suggest that these intraergastoplasmic tubular structures might constitute an extremely helpful differential marker.

Pulmonary blastoma. Report of two cases in children.

Pulmonary blastoma is a rare tumor of the lung. Although it has been stated that this is predominantly a tumor of adults, a review of the 42 cases published to date reveals that it is a disease which occurs with some frequency in children. The tumor is relatively benign compared to pulmonary carcinosarcoma. Of the eight cases previously described in children, three are known to have survived and to be free of disease 10 months, 3 and 8 years after surgical resection. We report two additional cases of pulmonary blastoma in children followed for 34 and 26 months without any evidence of recurrence or metastases.

Esophageal Crohn's disease: medical management and correlation between clinical, endoscopic, and histologic features.

SUMMARY: : Esophageal involvement in patients with Crohn's disease, initially thought to be rare, has been documented with increasing frequency in both retrospective and prospective studies. However, there is no documented standardized medical regimen for treatment of these patients. We report five cases of esophageal Crohn's disease as well as a review of the literature emphasizing therapeutic approach and increased incidence of corticosteroid dependence in these patients. In the past, patients with significant esophageal disease and symptoms have been surgical candidates. We recommend that all patients with symptoms of dysphagia, odynophagia, chest pain, or dyspepsia with documented esophageal Crohn's disease should receive H2 receptor antagonists as part of their medical regimen. In addition, immunosuppressant agents should be considered as adjuvant therapy in steroid-dependent patients with esophageal disease involvement.

Systemic necrotizing vasculitis associated with childhood sarcoidosis.

Childhood sarcoidosis is a rare disorder with protean manifestations. The case of a child with prolonged fever, hepatosplenomegaly, pancytopenia, and systemic necrotizing vasculitis manifesting as fever, rash and skin infarctions, digital pregangrene, and foot drop is reported. This is the first case of systemic necrotizing vasculitis reported in sarcoidosis. The fulminant course of the disease required treatment with intravenous pulsed cyclophosphamide and high doses of corticosteroids. The spectrum of vasculitis in childhood and adult sarcoidosis is reviewed.

Selective fascicular stimulation of the rat sciatic nerve with multipolar polyimide cuff electrodes.

PURPOSE: To assess a new flexible, multicontact spiral-cuff electrode made of polyimide with integrated platinum contacts for selective stimulation of nerve fascicles. METHODS: Polyimide cuff electrodes with 12 Pt sites in the spiral cuff were acutely implanted around the sciatic nerve of rats. Stimulation was applied through each one of the four tripoles of the cuff as single pulses of 10 microsec duration of increasing intensity. The motor responses were monitored from EMG recordings of gastrocnemius medialis (GM; innervated by the tibial nerve) and tibialis anterior (TA; innervated by the peroneal nerve) muscles. The torque developed in tbc ankle was simultaneously measured by means of a purposely designed apparatus. Recruitment curves were constructed for the CMAP of the GM and TA muscles and for the torque. RESULTS: In all nerves evaluated stimulation through one or two of the tripoles initially evoked a dorsiflexion with parallel recruitment of the TA muscle at low stimulation intensity; at higher stimulation amplitude activation of the tibial innervated muscles prevailed and led to predominant plantarflexion. On the other hand, stimulating through the other two or three tripoles evoked plantarflexion from the beginning, with increasing force from low to high stimulus intensity. The effectiveness of selective stimulation was mildly increased by applying a simultaneous transverse steering current. The threshold for torque dorsiflexion decreased and the dynamic range of stimulation that resulted in a net dorsiflexion expanded. The effects of steering currents were more noticeable with pulses of 80% than 40% of threshold value, and when applied from an opposite than from an adjacent anode. CONCLUSIONS: Despite the relative small size of the rat sciatic nerve and the close apposition of tibial and peroneal fascicles, we proved the feasibility of using multipolar polyimide cuff electrodes to produce selective fascicular nerve stimulation.

Peripheral nerve regeneration through microelectrode arrays based on silicon technology.

This paper describes some developments, made to obtain a chronic neural interface to record signals from regenerated peripheral nerves. Microperforated silicon dices, fabricated by techniques compatible with CMOS processes, were coupled in silicone nerve chambers and implanted between the severed ends of peripheral nerves in rats. Three configurations of perforated dices with 25 via-holes of 100 µm diameter, 121 via-holes of 40 µm and 400 via-holes of 10 µm were assessed. The feasibility of axonal regeneration through the dices via-holes was proved by histological and physiological methods over 3 months post-implantation. The regenerated nerves were organized in fascicles corresponding to the grid pattern of the via-holes. However, nerve regeneration was difficult and distal re-innervation delayed with respect to simple tubulization repair. The size of the via-holes and the total open area are determinants of the degree and quality of regeneration. Further improvements are needed in both the microelectrode dice design and in neurobiological stimulation of regeneration.

Congenital acute T lymphoblastic leukaemia: report of a case with immunohistochemical and molecular characterisation.

A newborn infant with congenital T cell lymphoblastic leukaemia presented with hepatosplenomegaly and pancytopenia at birth and died on the 21st day of multi-organ failure. Biopsy and necropsy examination showed extensive atypical lymphoid infiltrates in the lungs, liver, spleen, kidneys, lymph nodes, and bone marrow. Immunohistochemically, the lymphoid cells were TdT+, CD3+, CD45RO+, and CD10-, CD79a-, CD20-. Genotypic analysis using polymerase chain reaction showed T cell receptor gamma chain gene rearrangement and absence of immunoglobulin heavy chain gene rearrangement. This appears to be the first documented case of congenital T cell lymphoblastic leukaemia. The case had unusual histological and immunogenotypic features, disseminated early, and pursued a highly aggressive course. Consideration of the diagnosis is of paramount importance. The immunophenotypic studies and molecular characterisation of such congenital leukaemias are critical in arriving at a definite diagnosis.