immunity involving a CD3+CD4+ deﬁcit and decreased prolif- erative response. 4 Puglisi et al. have recently described two cases of 11q terminal deletion disorder and common variable immu- nodeﬁciency (CVID). 5 Although data on the use of IVIG therapy in JS patients is scarce, the clinical and immunological similarities of our case with CVID lead us to assume its effectiveness. In conclusion, we underline the need for multidisciplinary management of patients with JS and other polymalformative syndromes and execution of an adequate immunological study, particularly if they present severe or repeated infections. The indication to initiate treatment with IVIG should be individual- ised and determined by the patient’s prognosis for survival. Acknowledgements We would like to thank Ms. Celine Cavallo for assistance with the English version of the paper. Dr Carolina Fernández-San José 1 Dr Andrea Martín-Nalda 1 Dr Teresa Vendrell Bayona 2 Dr Pere Soler-Palacín 1 1 Pediatric Infectious Diseases and Immunodeﬁciencies Unit 2 Department of Genetics Vall d’Hebrón University Hospital Barcelona Spain References 1 Mattina T, Perrotta CS, Grossfeld P. Jacobsen syndrome. Orphanet J. Rare Dis. 2009; 7: 4–9. 2 Sirvent N, Monpoux F, Pedeutour F et al. Jacobsen’s syndrome, thrombopenia and humoral immunodeﬁciency. Arch. Pediatr. 1998; 5: 1338–40. 3 Miller CDE, Atkinson AR, Roifman CM. Immunodeﬁciency in Jacobsen syndrome. J. Allergy Clin. Immunol. 2003; 1: S232. 4 Von Bubnoff D, Kreiss-Nachtsheim M, Novak N et al. Primary immunodeﬁciency in combination with transverse upper limb defect and anal atresia in a 34-year-old patient with Jacobsen syndrome. Am. J. Med. Genet. A 2004; 126: 293–8. 5 Ming JE, Stiehm ER, Graham JM Jr. Syndromic immunodeﬁciencies: genetic syndromes associated with immune abnormalities. Crit. Rev. Clin. Lab. Sci. 2003; 40: 587–642. 26 August 2010 Dear Editor, MESENTERIC CYST IN A NEONATE CAUSING OBSTRUCTIVE UROPA- THY AND SECONDARY TYPE 1 PSEUDOHYPOALDOSTERONISM – A CASE REPORT Mesenteric cysts are rare intra-abdominal lesions with an inci- dence of 1 per 140 000 general hospital admissions and 1 per 20 000 paediatric hospital admissions. 1 Pseudohypoaldoster- onism (PHA) is one of the rare conditions in neonates which cause hyperkalaemia and salt loss, accompanied by vomiting, failure to thrive and dehydration. 2 Various presentations of mesenteric cyst have been described in literature. 3,4 An exten- sive PUBMED search did not reveal a single case of a mesenteric cyst in paediatric age group presenting as secondary type 1 hypoaldosteronism. We herein present a rare case of a mesen- teric cyst in a neonate causing obstructive uropathy and sec- ondary type 1 PHA. In September 2009, a nine-day-old female infant presented with 2 days of refusal to feed, lethargy and anuria. There was no history of fever, convulsions, vomiting or diarrhoea and the infant was exclusively breastfed. She was born at term by spontaneous normal vaginal delivery to a multigravida mother after an unremarkable pregnancy. Ultrasonography was not performed during the pregnancy. She had a birthweight of 3100 g and was discharged on day 3 exclusively on breastfeed- ing. On examination, the infant was dehydrated, lethargic and afebrile with acidotic breathing. The heart rate was 140/min, respiratory rate, 38/min and mean blood pressure, 38 mmHg. Peripheral pulses were well felt and capillary reﬁll time was 3 s. Her weight was 2200 g indicating a weight loss of about 29%. Abdominal examination revealed a large abdominal mass occupying the whole of the abdomen and descending into the pelvis. It was ﬁxed with ill-deﬁned borders and dull on percussion apart from a small area of resonance due to a part of the overlying bowel. Other systemic examination was normal. The investigations at admission are shown in Table 1. Haemoglobin was 13 g/dL, total leukocyte count was 17 600/ cumm and platelet count was 2.6 lac/cumm. Liver function tests, coagulation proﬁle and septic screen including C-reactive protein were normal. The infant was catheterised and 7 mL of urine was recovered. Urinalysis showed protein (1+), occult blood (-), red blood cells 1/high power ﬁeld, and white blood cells 5/high power ﬁeld. Urine bacterial cultures were nega- tive. Initial ﬂuid resuscitation was done with 20 cc/kg of normal saline and intravenous cefotaxime was started. This was followed by correction for hyponatremic dehydration. Ultrasonography of the abdomen revealed a well-deﬁned cystic mass measuring 5.8 ¥ 7.6 ¥ 5.9 cm extending inferiorly compressing the ureters and causing pressure effect on both the kidneys leading to bilateral hydronephrosis. The bladder was empty with Foleys catheter tip seen in situ. Plain magnetic resonance imaging of the abdomen – T2-weighted images revealed a hyperintense lesion in the presacral space extending inferiorly into the perineum with a few septations within (Fig. 1). Exploratory laparatomy was done on day 10 of life. A huge mesenteric cyst was present in the abdomen between the bladder and the uterus compressing both ureters and causing bilateral hydronephrosis. The cyst was dissected away from the surrounding structures after decompression and a subtotal excision was done. Histopathology of the specimen showed mesenteric lymphangioma with lymph channels and lymphoid aggregates. Postoperatively, the infant was managed in the neonatal intensive care unit. Laboratory parameters done postoperatively serially are shown in Table 1. The infant had gained 256 g on the third day of admission. However, even after adequate correction of dehydration the electrolyte abnor- malities and acidosis persisted, and hence secondary type 1 PHA due to obstructive uropathy was suspected. Elevated serum aldosterone and renin levels in the presence of meta- bolic abnormalities conﬁrmed the diagnosis. Antibiotics and Letters to the Editor Journal of Paediatrics and Child Health 47 (2011) 484–488 © 2011 The Authors Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians) 486