Image 49: This 62 year old male came back from 6 months in Cambodia where he had been healthy except for a rare chill and possibly a low grade fever for the week before a friend, using his newly purchased ultrasound machine, told him he had a mass in his liver and to return to Canada. He is a known hepatitis C carrier who has had normal liver function in the past. When seen here a week later he had an US, CT and this MRI in an attempt to determine the origin of his liver "mass" He was afebrile, asymptomatic and had no abdominal tenderness, palpable liver tenderness or enlargement. His lab tests were WBC 11.3 (n <10.8), Hgb 115 (n >140), AST 76 u/L (n <37), alk. phos. 252 (n <129). His WBC differential was normal. What is your diagnosis?  x

49

Image 49:  This was an almost-asymptomatic amoebic liver abscess. A stat (same day) ELISA  for Echinococcus granulosus was negative and for E. histolytica was very positive with an OD 2.66 (negative < 0.35) at the NRCP (National Reference Centre for Parasitology-McGill U). An ultrasound-guided aspiration of the mass yielded 10 ml of gray viscous material which had moderate numbers of degenerate WBCs and much amorphous debris. No amoebae were seen in the material aspirated from the edge, but the E. histolytica PCR on this same material was positive (the E. dispar PCR was negative) at the LSPQ (Quebec Public Health Laboratory). The patient responded to metronidazole 750 tid for 10 days with an improved feeling of well being, no further intermittent chills and a drop in his WBC count to normal.