余秉軒¹、黃逸修^1,2,3、黃志賢^1,2,3

¹臺北榮總泌尿部；²國立陽明大學醫學系泌尿學科；³書田泌尿科學研究中心 

Ping-Hsuan Yu¹, Eric Yi-Hsiu Huang^1,2,3, William J.S. Huang^1,2,3

¹ Department of Urology, Taipei Veterans General Hospital;

² Department of Urology, School of Medicine, National Yang-Ming University;

³Shu-Tien Urological Science Research Center, Taipei, Taiwan

 

Introduction: Mucormycosis is a life-threatening fungal infection caused by Mucorales. These infections are mostly found in the nasal sinuses, brain, or lungs. Here we would like to report a rare case with mucormycosis over the whole abdominal wall in a patient with bladder cancer history without known immunosuppressive status. The infection is most likely related to the urine leakage from ileal conduit stoma. Intensive debridement and anti-fungal agents were used for disease control.

Case report: A 62-year-old male has a medical history of muscle invasive urothelial carcinoma of bladder. Other underlying diseases are type 2 diabetes mellitus and hyperlipidemia. He first underwent neoadjuvant chemotherapy in 2013, and then took the surgery of radical cystoprostatectomy with ileal conduit reconstruction at Taipei Veterans General Hospital on 2013/12/18. After the surgery, the patient was regularly followed at the urology outpatient clinic. No tumor recurrence was observed afterwards.

Since the early August in 2019, the patient noticed urine leakage from the ileal conduit stoma bag and causing erythematous change over the skin of central abdominal wall. The erythematous area progressed, and skin erosions developed surrounding the stoma. The patient first visited other hospital and was admitted for parenteral antibiotics treatment. The enterostomal therapist was consulted and Aquacel Ag was used to cover these erosive wound. However these treatments did not show much improvement on this patient. With disease progression, the patient was transferred back to Taipei Veterans General Hospital.

Upon visiting the patient at emergent department, the erythematous area extended to the whole abdominal wall with induration and mild tenderness. We inserted Foley catheter into the ileal conduit stoma to divert urine. Computed tomogram was arranged at emergent department, and only subcutaneous inflammation change was detected. No intra-abdominal abscess was detected otherwise. After admission, even under empiric antibiotics coverage, the erythematous area still progressed, and pustules developed on the edge of affected skin. The skin gradually turned necrotic and gangrene change. With his cancer history, skin metastasis was suspected. Due to rapid disease progression and unusual presentation, dermatologist was consulted for skin biopsy. Infectious physician was consulted as well for pus smear. As a result, much hyphae was observed microscopically, and mucormycosis was impressed. No malignant cells were detected, and the fungal culture revealed Rhizopus species.

As the diagnosis was established, amphotericin B was initiated for disease control. Plastic surgeon was consulted for debridement. The bilateral percutaneous nephrostomy drainage was performed to prevent urine from contaminating the wound, and then debridement was carried out. All the skin over the abdominal wall was removed and the debridement was down to the fascia and muscle layer. The mucosa of the stoma remain healthy appearance without evidence of fungal infection, so the ileal conduit was not removed during the operation. Because of the loss of body surface, the patient was transferred to intensive care unit for post-OP care. Mold growth could be observed directly on the remnant muscle in the following days. Multiple bed-side debridement was done in the intensive care unit. Besides amphotericin B, Caspofungin was prescribed as well.

Given immunosuppressive status was suspected, evaluation was arranged including autoimmune profile, HIV infection, and cortisol level. All the surveys mentioned above revealed negative findings. The patient has a history of diabetes mellitus, but recent HbA1c level was acceptable. He admitted to take some “dietary supplements” from uncertified origin, which might be a resource for steroid exposure.

Conclusions: Mucormycosis is a lethal disease and is rarely found over the abdominal wall. All the causes related to immunosuppressive status should be evaluated, including diabetes and HIV infection. Intensive and aggressive debridement is warranted for disease curation. Amphotericin B is the anti-fungal agent of choice in such condition. However the significant adverse effects such as renal function deterioration should be informed before carrying out the treatment.