Successful management of renal mucormycosis with antifungal therapy and drainage.

We report a case of isolated extensive renal mucormycosis in an immunocompetent adult, who was successfully managed conservatively without surgical debridement. To the best of our knowledge, this is the first case where antifungal therapy alone was sufficient even with such an extensive involvement.

INTRODUCTION

Mucormycosis is an opportunistic infection of the human body, seen mainly in immunosuppressed states. Renal involvement usually occurs in disseminated forms and is seen in up-to 19% of such cases.[1] Isolated renal involvement has usually been reported as case reports. However, majority of the patients (75%) suffering from isolated renal mucormycosis in India are apparently healthy individuals.[2] The standard treatment is early surgical debridement along with systemic antifungal therapy. Despite this, the mortality remains high. We report a case of isolated extensive renal mucormycosis in an immunocompetent adult, who was successfully managed conservatively.

CASE SUMMARY

A 40-year-old gentleman presented to the Department of Urology with complaints of right flank pain, mass, and fever of 1 month duration. He also complained of anorexia and weight loss. There was no history of hematuria and lower urinary tract symptoms. On examination, he was pale and emaciated. He had tachycardia (120/min), but stable blood pressure (110/60 mm Hg). Abdominal examination revealed a 10 cm × 10 cm tender, hard mass occupying right lumbar and hypochondrial region. The skin over the mass was edematous. His investigation revealed hemoglobin of 5.7 g/dl, marked leukocytosis (32,000/mm3), and serum creatinine of 1.3 mg/dl. Contrast enhanced tomography of the abdomen showed a large hypodense mass completely replacing the right kidney, with the loss of fat planes with inferior vena cava, duodenum, psoas muscle, and colon [Figure 1a and b]. Fine needle aspiration cytology (FNAC) was performed due to a suspicion of renal cell carcinoma which revealed broad based aseptate hyphae on the periodic acid-Schiff stain, suggestive of mucormycosis. The patient was started on liposomal amphotericin B (3 mg/kg). His ELISA for HIV infection was negative. There was no history of sexual promiscuity, homosexuality, steroid intake, or any recent major illness. He was a farmer by occupation. His blood work-up was not suggestive of any hematological malignancy, and there was no history of recurrent infections in the past. His fever spikes decreased in severity and leukocyte count decreased to 17,000/cumm. In view of extensive renal involvement, he was taken for surgical debridement. Intraoperatively, the right side retroperitoneum was frozen with a pale hard mass and extensive infiltration of meso-colon. It was decided to abandon the procedure and a biopsy from the mass was taken. The Grocott methenamine stain of biopsy specimen showed the evidence of broad, aseptate fungal hyphae which were easily foldable upon themselves, confirming the morphology of mucormycosis [Figure 2a and b]. Postoperatively, liposomal amphotericin B was continued in a dose of 3 mg/kg body weight. The patient continued to improve on antifungal therapy and was subsequently discharged in a stable condition on the 10th postoperative day, with advice to continue amphotericin B for a cumulative dose of 3 g. At 2 months from discharge, the patient presented with purulent discharge from the suture line. The pus was drained, the microscopy and the culture were negative for fungal hyphae. He was clinically better and had regained his appetite and weight. Imaging showed a perinephric collection [Figure 3a], which was drained percutaneously using a pigtail catheter. He continued to have repeated episodes of purulent discharge from the lateral edge of the surgical wound even after this initial drainage. Hence, an open drainage of the underlying collection was performed under general anesthesia. He showed marked improvement thereafter. Follow-up computed tomography abdomen at 8 months showed a residual small mass in right renal fossa [Figure 3b].

Figure 1

(a and b) Contrast enhanced computed tomography scan showing nonenhancing right renal mass with extensive involvement of surrounding structures

Figure 2

(a) High power view shows areas of necrosis and faint fungal profiles (periodic acid-Schiff, ×400) (b) many broad, aseptate fungal profiles are seen which are easily foldable upon themselves confirming the morphology of mucor (Grocott methanamine stain, ×200)

Figure 3

(a) Follow-up computed tomography scan at 2 months showing a diffuse hypodense area involving renal fossa suggestive of extensive liquefaction. (b) Follow-up computed tomography scan at 8 months showing residual small hypodense lesion in the renal fossa

DISCUSSION

Although renal mucormycosis is rare and generally occurs as a part of disseminated disease, its presentation as renal mass, mimicking malignancy, as was seen in our case, has not been reported in the literature. Disseminated mucormycosis generally occurs in the immunocompromised host and has a high mortality reported up to 75–100%. Survival after isolated renal mucormycosis has been reported to be 65% with combined surgical debridement and antifungal therapy.[3] Our case was immunocompetant. Early diagnosis and surgical debridement with antifungal therapy are thus the standard treatment of choice for renal mucormycosis. In our patient, surgery was not feasible as this would have involved major vascular resection and a significantly increased risk of mortality on the table. Survival with antifungal therapy alone, without surgical debridement, has never been reported in English literature. Chakrabarti et al.[4] in their 10 years of experience reported two cases of isolated renal mucormycosis, who were treated with antifungal therapy alone but did not survive. Since mucor is an angio-invasive fungus causing extensive necrosis, antifungal therapy alone fails because of poor tissue penetration. Our patient survived on antifungal therapy alone with additional drainage of sterile pus at a later date. Although he had a small residual collection, he had regained weight and appetite, prompting us to avoid further surgery. The pus-aspirate was negative for fungal hyphae. The reason for such a successful response is not clear, but our case shows that antifungal therapy, even in extensive renal mucormycosis can be a ray of hope in inoperable cases.

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Conflicts of interest

There are no conflicts of interest.