Sex: male
Age: 40 years
History
Weight loss (6 kg over 2 months), itching, onset of jaundice two weeks after three days of fever treated with trimethoprim-sulfamethoxazole for 4 days (800 mg/day per os).
Laboratory data
Total bilirubin 5.6 mg/dl, direct bilirubin 3.5 mg/dl, g GT 320 U/L, AP 516 U/L, HBs Ab +, HBc Ab + (IgG), HCV Ab-
Physical findings
Jaundice, no other findings.
Case text
The patient was admitted to the hospital because of the onset of jaundice.
Image1-4
Ultrasound of the liver.
Axial scan on the hepatic veins (image 1), longitudinal scans of the right lobe (image 2), of the inferior vena cava (image 3) and of the left lobe (image 4).
Image 5-7
CT of the upper abdomen.
Axial non-enhanced CT scan of the liver (image 5); axial contrast-enhanced CT scans of the liver (images 6,7).
Image 8-9
MRI of the upper abdomen.
Axial T1-weighted spin-echo weighted image (TR/TE 420/15) (image 8). Axial T2-weighted spin-echo image (TR/TE 1820/80) (image 9).
Image 1-4
1. What is the abnormality present on the US scan of the liver?
Multiple focal hyperechoic areas.
2. Are there any findings as to size and morphology of the liver?
No remarks.
3. What is your diagnosis?
Diffuse benign liver disease (multifocal steatosis).
4. What is the differential diagnosis?
Multiple metastases or multiple hemangiomas.
5. What is your next diagnostic step?
CT of the liver.
Image 5-7
6. What is the abnormality present on the CT scan of the liver?
Multiple focal hypodense areas that are still hypodense after administration of contrast media.
7. What is your diagnosis?
Diffuse benign liver disease (multifocal steatosis).
8. What is the differential diagnosis?
Multiple metastases.
9. What is your next diagnostic step?
MRI of the liver.
Image 8-9
10. What is the abnormality present on the MRI of the liver?
Multiple focal hyperintense areas on the T1-weighted spin-echo image showing decreased signal intensity on teh T2-weighted spin-echo image.
11. What is your diagnosis?
Diffuse benign liver disease (multifocal steatosis).
12. What is the differential diagnosis?
None.
13. What is your next step?
Liver biopsy.
The liver biopsy showed macrovacuolar steatosis and stasis of bilirubin within the hepatocytes and in the biliary ducts. The case is consistent with drug induced liver disease. The patient recovered completely and US follow-up showed a normal pattern six months later.
Final diagnosis
Drug induced liver disease.
Differential diagnosis
US findings suggest:
1. diffuse benign liver disease (multifocal steatosis)
2. multiple metastases
3. multiple haemangiomas
CT and MRI findings rule out the latter two hypotheses because of the lack of enhancement on CT and of the signal intensity pattern on MRI.
Discussion
The presented case is unusual both as to clinical and radiological features. Trimethoprim-sulfamethoxazole at the low administered dose is very well tolerated by the liver and to our knowledge only one case of intrahepatic cholestasis induced by this drug was reported in the literature.
As to radiological findings, diffuse benign liver disease usually shows two distinct patterns on US (bright liver and centrolobular pattern). The finding we showed is totally different and exceptionally reported. The different imaging modalities (US, CT and MRI) show that the multifocal lesions are related to a multifocal increase of fat in the liver, as confirmed by biopsy.