Encrusting cystitis due to Corynebacterium urealyticum in a patient with ANCA-associated vasculitis: case report and review of the literature.

OBJECTIVES: To report a patient with systemic ANCA-associated vasculitis, under maintenance treatment, who had persistent microscopic hematuria and developed recurrent pelvic pain due to Corynebacterium urealyticum encrusting cystitis. The relevant literature on this infection is reviewed.
METHODS: Descriptive case report and a review of the literature (PubMed search).
RESULTS: A 39-year-old woman on maintenance therapy for systemic ANCA-associated vasculitis, diagnosed 10 months earlier and with persistent microscopic hematuria, developed recurrent pelvic pain. She had received several immunosuppressants (including cyclophosphamide and rituximab) since the onset of her vasculitis, as well as cycles of broad-spectrum antibiotics during the acute initial phase of her disease. Computerized tomography of the pelvis and cystoscopy showed several encrusted calcifications in the bladder mucosa, and, finally, urine culture (selective media) led to the diagnosis of C. urealyticum infection. Most of the bladder-encrusted stones were removed during cystoscopy and daily intramuscular teicoplanin injections were given for 14 days. Her symptoms disappeared rapidly and completely. On reviewing the literature, immunosuppression, previous broad-spectrum antibiotics, urogenital alkaline pH, and prolonged bladder catheterization are predisposing factors for this rare infection. C. urealyticum encrusting cystitis has been reported in patients with systemic diseases but not yet in ANCA-associated vasculitis. Outcome is almost always good under adequate antibiotic therapy, mainly glycopeptides.
CONCLUSION: Physicians should be aware of this unusual but potentially emerging infectious complication that can be challenging in ANCA-associated vasculitis, because the urinary tract can be affected by the vasculitis or as a complication of previous cyclophosphamide therapy.