Filariasis an Unusual Cause of Retroperitoneal Fibrosis, Hydronephrosis, and Infertility in a Young Adult Male

Filariasis is a tropical disease caused by infection with nematode parasites of the Filarioidea family. Filariasis is an endemic disease in parts of India, Sub-Saharan Africa, and Southeast Asia. Filariasis is a progressive disease predominantly affecting the lymphoreticular system, which can result in genitourinary complications (hydrocele, scrotal pain, and infertility), lymphedema, and elephantitis. Retroperitoneal fibrosis has a broad etiology, including secondary to chronic infection. Currently an estimated 25 million men are suffering from lymphatic filariasis with urogenital involvement worldwide. We present a rare case of a 40-year-old man presenting with fever, groin lymphadenopathy, and a history of infertility. Imaging confirmed significant hydronephrosis and retroperitoneal fibrosis. Filariasis serology was positive. Prior bilateral testicular biopsy demonstrated chronic inflammation and atrophy. Disease course was not improved by empirical eradication and supportive retrograde ureteral stenting. The patient developed elephantitis and progressive retroperitoneal fibrosis leading to a solitary functioning right kidney with nephrostomy. Urologists should be aware of index presentations of filariasis and its associated urological complications, particularly in the travelling adult population in whom the etiology of renal impairment and infertility remains unclear.