Bilateral renal lymphangiectasia—an unusual cause of abdominal distension and flank pain in a child

Renal lymphangiectasia (RL, also known as renal lymphangiomatosis or renal lymphangioma or parapelvic lymphangiectasia) is an uncommon benign disorder characterized by dilatation of perirenal, peripelvic and intrarenal lymphatic channels secondary to obstruction (1,2). About five cases of this entity in pediatric age group have been illustrated in literature till date (3-7). Diagnosis is based on the characteristic radiological findings. An 11-year-old male patient presented with the history of fatigue, progressively increasing abdominal distension and bilateral flank pain since last 2 months. Past history and family history was unremarkable. General physical examination including blood pressure was normal. Per abdomen examination revealed dull note on abdominal percussion suggestive of ascites. Routine laboratory investigations including complete blood profile, blood urea and serum creatinine were normal. Plain and contrast enhanced computed tomography (CECT) of abdomen was done. Topogram of CT abdomen showed diffusely increased density of abdomen with bulging flanks and poor definition of liver, spleen & psoas muscles along with the medial displacement of bowel loops (Figure 1). Plain CT axial sections of the abdomen showed septated fluid collection in bilateral perinephric and peripelvic space along with ascites (Figure 2). The septa in septated collections showed enhancement on contrast enhanced CT (Figures 3,4). The diagnosis of RL was made based on the pathognomonic imaging features. Diagnostic and therapeutic ascitic fluid tap was performed under ultrasound (US) guidance. Laboratory analysis of the fluid revealed high protein concentration with few lymphocytes. Patient was kept on the diuretics and showed significant improvement on follow-up