College Answer
a)
Veno-occlusive disease of the liver (sinusoidal obstruction syndrome)
b)
Liver USS showing ascites and reversal of portal vein flow
Discussion
Let us dissect the results systematically.
The electrolytes look deceptively normal. However, an exam candidate accustomed to playing these games will recognise the presented panel as an invitation to calculate the anion gap. If one does this, one will discover that it is raised.
(142 + 4.8) - (97 + 22) = 27.8
There does not seem to be much of a metabolic acidosis associated with this, which is a little weird (delta ratio is very high, which could suggest that there is some sort of pre-existing metabolic alkalosis present).
The ure and creatinine are raised, but not to a significant degree. Certainly not by a degree that might explain this weight gain with renal-related fluid overload.
The calcium and phosphate are trivially deranged; the normal phosphate suggests that the accumulation of retained non-volatile acids of renal failure is probably not responsible for the high anion gap.
Liver enzymes are deranged. ALT AST and GGT are all elevated, and even though alkaline phosphatase is not reported one can generally comment that there is non-specific liver injury occurring (i.e. the right upper quadrant pain is probably not acute cholecystitis, but rather the feeling of a swollen liver distending its capsule). The liver injury also suggests that lactate could explain the raised anion gap.
In summary:
- High anion gap, probably due to lactate
- Renal impairment
- Liver injury
- Oedema
None of these are parfticularly specific and you'd be struggling to narrow your list of differentials, but the college helpfully threw in the story about a recent bone marrow transplant. That's a giveaway. In the pattern recognition algorithm of the exam candidate, liver injury + BMT = VOD. Veno-occlusive disease tends to occur in the first three weeks after the transplant, and typically manifests with weight gain and a painful liver. The major clinical criteria for diagnosis (Seattle criteria and Baltimore criteria) usually also demand ascites, hepatomegaly and a bilirubin level (which we were not supplied with; it would have to be over 34 mmol/L).
Diagnosis does not require ultrasound, but it is usually ordered in this context. The BCSH/BSBMT guidelines (2013) concluded that "the main role of ultrasound is to exclude the presence of other diagnoses" because the ultrasound findings which are usually associated with VOD are insufficiently sensitive and specific. In any case, here they are:
- Ultrasound-confirmed ascites
- Ultrasound-confirmed hepatomegaly
- Splenomegaly
- Attenuated or reversed hepatic venous flow
- Thickened gallbladder wall
- Ultrasound evidence of increasing hepatic artery vascular resistance (there is a "hepatic artery vascular resistance index", which is helpful in the diagnosis if it is greater than 0.75.)