Mucormycosis of the bile duct: A Case Report

CASE REPORT

A 54 year old female patient presented to us with a one and a half year history of recurrent cholangitis. She had undergone elective open cholecystectomy with common bile duct exploration 2 years ago for cholecystitis with choledocholithiasis. On investigation she was non-diabetic and tests for HBsAg and HIV were negative. Her ultrasound and CT scan reports revealed post-operative cholecystectomy status with dilated intra-hepatic bile radicals and dilated common bile duct. She was subjected to percutaneous transhepatic biliary drainage to alleviate her rising bilirubin; this showed dilated system with cluster of balls of fluffy shadows, a pattern suggesting mucormycosis (Fig. 1). Bile culture showed growth of mucormycosis at the end of the sixth day. Intravenous amphotericin B was administered as a 1mg/kg infusion in 5% dextrose over 6 hours, but the patient ultimately died.

DISCUSSION

Mucormycosis is a relatively uncommon opportunistic fungal infection caused by fungi of the order Mucorales, generally called Mucor.(1)The disease occurs in association with diabetes mellitus, leukaemias, and lymphomas.(1) According to the literature (2) at least five clinical entities caused by Mucor have been described, including rhinocerebral, pulmonary, cutaneous, gastrointestinal, and disseminated disease. Fungi of the order Mucorales have minimal intrinsic pathogenicity but can cause aggressive and fulminant infections, particularly in the immunocompromised and diabetic patient.(3, 4)

Of the five clinical entities of infection with Mucor, gastrointestinal mucormycosis is uncommon and accounts for only 7% of all patients;(5) the stomach is the most common site of involvement.(3) The intestinal form has a predilection for the terminal ileum, the caecum, and the colon.(1,3) With little exception, gastrointestinal mucormycosis pursues a fulminant and rapidly fatal course,(3) and survival is largely dependent on proper diagnosis accompanied by surgical resection of the infected bowel along with administration of intravenous amphotericin B.

Fig 1: Percutaneous transheptic cholangiogram showing characteristic
features suggestive of mucormycosis.

Regardless of the site involved, histologic examination of the lesion shows broad, irregularly shaped, and non-septate hyphae with right-angle branching.(1,2,3,4,5) Fungi of the order Mucorales exhibit a remarkable tendency to infiltrate the walls of blood vessels, especially arteries. They grow profusely into the vessel lumen and initiate acute vasculitis and thrombosis of major blood vessels. As a result of such vascular thromboses, ischemic infarction can occur in any organ.(2,6) In some instances, venous involvement with thrombosis causes haemorrhagic necrosis.(4)

Literature reports of hepatic mucormycosis (5,7) describe postmortem macroscopic and microscopic examination finding in liver tissue for thrombus in hepatic vessels, irregular areas of necrosis, and extensive ischemic necrosis of hepatocytes.

REFERENCES

1. Calle S, Klatsky S. Intestinal phycomycosis (mucormycosis). Am J Clin Pathol. 1966;45:264–72.

2. Lehrer RI, Howard DH, Sypherd PS, Edwards JE, Segal GP, Winston DJ. Mucormycosis. Ann Intern Med. 1980;93:93–108.

3. Lyon DT, Schubert TT, Mantia AG, Kaplan MH. Phycomycosis of the gastrointestinal tract. Am J Gastroenterol. 1979;72:379–94.

4. McBride RA, Corson JM, Dammin GJ. Mucormycosis: two cases of disseminated disease with cultural identification of Rhizopus: review of literature. Am J Med. 1960;28:832–46

5. Meyer RD, Rosen P, Armstrong D. Phycomycosis complicating leukemia and lymphoma. Ann Intern Med. 1972;77:871–79.

6. Hagspiel KD, Kempf W, Hailemariam B, Marincek B. Mucormycosis of the liver: CT findings. AJR. 1995;165:340–42.

7. Vallaeys JH, Praet MM, Roels HJ, Marck EV, Kaufman L. The Budd-Chiari syndrome caused by a zygomycete: a new pathogenesis of hepatic vein thrombosis. Arch Pathol Lab Med. 1989;113:1171– 4.