1. MUCORMYCOSIS: A LETHAL DISEASE?
Stanley Mugambi1, Andre Theron1, Komala Pillay2, Sharon Cox1, Alp Numanoglu1 and Alastair Millar* 1
University of Cape Town and Departments of 1Paediatric Surgery and 2Anatomical Pathology, Red Cross War Memorial Children’s Hospital, Cape Town, South Africa
Introduction
Mucormycosis is a fungal infection caused by moulds of the class Zygomycetes, order Mucorales, with Rhizopus being the most common pathogenic species. Zygomycetes are found commonly in organic matter and soil. The fungus may gain entry through the nasopharynx by inhalation of spores, can be swallowed in contaminated food, or invade through broken skin or mucosa. Host susceptibility is dependent on the status of the body’s immune defence system.
Method
We present two illustrated case reports of disseminated mucormycosis and necrotizing fasciitis in immune compromised patients.
Case 1
A 3-month-old male untreated HIV infected infant presented in septic shock and a right flank mass with clinical evidence of abdominal wall necrotizing fasciitis.
Findings and procedure at laparotomy:
Full thickness dry necrosis of the abdominal wall with disintegration of the terminal ileum, caecum and ascending colon forming an inflammatory mass around a central cavity filled with bowel effluent. The right kidney and ureter were necrotic with a grey-black and velvety appearance. The lateral duodenal wall serosa was greyish but not perforated. The abdominal wall was excised to bleeding edges and the necrotic bowel was resected and the ends tied off. A right nephrectomy was performed.
Daily re-look laparotomies with further debridements documented rapid progression of necrosis. At the 4th laparotomy the necrosis had progressed to involve the retroperitoneum and para-spinal muscles, posterior right hemi-diaphragm, inferior vena cava and duodenum and had advanced further within the liver. At this stage the patient was in multi-organ failure and deemed unsalvageable. Palliative treatment was then offered and the patient died within 24 hours.
Case 2
A 3 year old male who had completed the second course of chemotherapy for Burkitt’s lymphoma two weeks previously was admitted to ICU with febrile neutropenia, severe mucositis, intestinal obstruction and a small bullous lesion on the left lower abdomen. Deep vein thrombosis in left iliac vessels was noted on ultrasound scanning.The bullous lesion rapidly evolved within hours into a necrotic patch signaling possible necrotizing fasciitis of the abdominal wall. The left lower limb became ischaemic, swollen, cold and pulseless.
Extensive full thickness necrosis of the left lower abdominal wall, necrotic segments of small and large bowel with extensive greyish discoloration of surrounding tissue including the left ureter. The left iliac vein and artery were thrombosed, with extension into the femoral vessels. Surgery included extensive necrosectomy of the anterior abdominal wall, necrotic bowel resection and arterial and venous thrombectomy. Further surgery was considered inappropriate. The child died the following day.
Results
Histology in both cases showed necrosis with fungal invasion consistent with mucormycosis.
H & E stain showing broad non-septate fungal hyphae with 90 degree branching consistent with that seen in Mucormycosis plugging vessels and infiltrating through to the surrounding necrotic tissue
Full thickness necrosis of the left lower abdominal wall, necrotic segments of small and large bowel with extensive greyish discoloration of surrounding tissue including the left ureter
Right nephrectomy specimen showing extensive hemorrhagic infarction
The left iliac vein and artery were thrombosed with extension into the femoral vessels
Clinical appearance of abdominal wall and abdominal contents at surgery
Discussion
Infection with mucormycosis can present as rhinocerebral, central nervous system, pulmonary, cutaneous, and gastrointestinal disease or can be disseminated. Anaerobic, high CO2 environment is a promoter of fungal growth, virulence and spread, while impairing phagocytic function. Both these cases had small and large vessel involvement. The infarcted, necrotic tissue in patient 1 had a greyish hue with a dry velvety texture. Cases of mucormycosis infection in healthy, immune competent individuals are rare and tend to be focal. Premature neonates are at risk. Unusual incidents of neonatal mucormycosis have occurred when patients were exposed to contaminated objects within the hospital setting. It is evident from histopathological assessment of affected tissues that the fungus invades vessels leading to thrombosis and tissue necrosis. Diagnosis is often difficult and delayed, and outcome is usually fatal. Rapid administration of systemic antifungals and extensive and complete surgical debridement of all affected tissue is the treatment of choice and the only hope for cure, but these measures are usually implemented too late. The disease affects mostly immune compromised hosts and in this situation is invasive and lethal.
References:
1.Petrikkos G, Skiada A, Lortholary O, Roilides E, Walsh TJ, et al. (2012) Epidemiology and clinical manifestations of mucormycosis. Clin Infect Dis 54: S23-34. 
Disclosure of Interest: None Declared