Diagnosis of histoplasmosis in urine cytology: reactive urothelial changes, a diagnostic pitfall. Case report and literature review of urinary tract infections.

Histoplasmosis not uncommonly causes systemic infection, particularly in immunocompromised patients. In systemic infection, the urinary tract is often involved, although the diagnosis of histoplasmosis in urine cytologic specimens has never been reported. Urinary tract histoplasmosis may present with gross hematuria, raising clinical suspicion for malignancy. The index case presented with intermittent gross hematuria, suprapubic pain, significant weight loss, hoarse voice, and a painful tongue ulcer. Examination of the patient revealed an ulcerated tongue lesion, an anal ulcer, a polypoid lesion on the vocal cord, and cystoscopic examination of the urinary bladder revealed erythematous patchy areas. Surgical biopsy sections from the vocal cord and tongue lesion were diagnostic of histoplasma infection. Urine cytologic examination showed atypical urothelial cells suspicious for malignancy. However, fungal stains performed on the urine specimen showed histoplasma organisms. We conclude that with a high index of suspicion, and the use of special stains, histoplasma organisms can be identified in urine.