An unusual case of bilateral renal enlargement due to primary renal lymphoma

Primary renal lymphoma is an uncommon variant of extranodal non-Hodgkin's lymphoma. Manifestations are usually nonspecific hematuria, fever, flank pain, and renal insufficiency. Pathological data are scanty; few reports indicate it has a very poor prognosis. We describe a child with bilateral symmetrically palpable kidneys, low-grade pyrexia, and arthralgia. Clinically, diagnosis was missed partly due to the fact that bilateral large renal tumors commonly produce asymmetric renal swelling, renal dysfunction, and hematuria which were absent in this case and partly due to rarity of the condition. However, radiological investigations combined with renal histology helped in establishing diagnosis in the present case.