Renal and perirenal abscesses are very rare in children. They can be present as an acute emergency condition or insidiously as a chronic disease. The diagnosis is not so obvious, and it is a big challenge, especially when it can simulate a kidney tumor. The treatment can be conservative, preferably with targeted antibiotics, or surgical, consisting primarily of drainage. This publication aims to present a clinical case in which both diagnosis and treatment were a big challenge for the entire treatment team. A 10-year-old male patient was admitted to the hospital because of mild abdominal pain and a temperature of 37.5 °C. The symptoms lasted for a week. In the computed tomography (CT), the lesion's dimensions were 11.1 × 8.2 × 25 cm, and inflammation, abscess, cyst, and abdominal tumor have been suggested. The decision about surgical treatment was made. An enormous abscess near the right kidney was localized. The patient's condition stabilized after surgery. Unfortunately, due to persistent purulent reservoirs, a second laparotomy was necessary. During the extensive diagnostic cystourethrography performed, vesicoureteral reflux was visualized. In conclusion, though a perinephric abscess is very rare in children, it should be taken into consideration in patients with non-specific abdominal symptoms. The imaging using ultrasound and CT scan with contrast enhancement is crucial to recognize and properly treat the condition. In terms of a small abscess, the only antimicrobial treatment using antibiotics of a broad spectrum can be considered. However, the drainage of an abscess, either percutaneous or open, should be used. For the large abscess, the open drainage seems to be a primary method of treatment. The importance of cooperation in a multidisciplinary team is crucial, as the diagnosis and treatment of underlying causes are essential.
Keywords: abscess; children; perirenal; renal; surgery.