Methicillin-resistant Staphylococcus aureus Infection in an Infant Causing Huge Perinephric Abscess Masquerading Cystic Wilm's Tumor

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as one of the important pathogens causing neonatal infections, often associated with high morbidity and mortality. We report the case of a 6-week-old female infant who presented with abdominal mass and poor feeding, without any fever spikes. Although computerized tomography scan of the abdomen and pelvis was suggestive of large solid-cystic tumor in relation to the left kidney, ultrasonography showed pyonephrosis; leading to diagnostic dilemma. In this unusual scenario, we performed minilaparotomy with placement of the incision such as to extend it further, if needed. However, on taking a small nick on the Gerota's fascia, thick yellowish-white pus started oozing out. About 450 cc of pus was drained on-table. Pus culture and sensitivity report yielded MRSA sensitive to vancomycin and gentamicin. The infant responded well to the above treatment. Presently, on a follow-up of 26 months, she is asymptomatic and thriving well.