Renal zygomycosis: an under-diagnosed cause of acute renal failure

Background. Invasive zygomycosis (mucormycosis) occurs predominantly in imm unocompromised patients in whom it carries a grave prognosis. While renal i nvolvement is not so uncommon in disseminated infection? isolated renal zyg omycosis is rare. Methods and Results. Forty-five patients with systemic zygomycosis were see n over a 12-year period from January 1986 to December 1997. Among these, 18 had renal involvement, nine with disseminated disease and nine with isolat ed renal zygomycosis. No underlying predisposing disease was identified in the majority of patients (72%). Renal involvement was confirmed at autopsy in 13 and by ante-mortem renal biopsy in five patients. The infection invol ved one kidney in five patients and was bilateral in the remaining. The man ifestations included fever, flank pain, haematuria and pyuria with evidence of enlarged non-functioning kidneys on computerised tomography (CT). Of th ose with bilateral disease, 12 (92.3%) had anuric acute renal failure. Anti -fungal therapy was given to sis patients (amphotericin B in mean total dos e of 1.1 g) and of these only two with unilateral disease who also underwen t nephrectomy survived while all the other 16 died. Conclusion, This study shows that renal zygomycosis has emerged as a cause of acute renal failure in the last decade since no patient with renal invol vement was identified at our centre prior to 1986 even though autopsies hav e been done regularly in patients dying of unknown causes. Bilateral renal zygomycosis should be suspected in any patient who presents with haematuria , Rank pain and otherwise unexplained anuric renal failure. Characteristic CT findings and an early renal biopsy can confirm the diagnosis and help in effective management of this serious disease.