Bloodwork for Hepatic Cysts

Diagnostic Approach

The European Association for the Study of the Liver (EASL) guidelines state that serum tumor markers (CEA and CA19-9) should not be ordered for complex hepatic cysts as they cannot reliably distinguish benign cysts from malignant lesions 1, 2
For asymptomatic simple hepatic cysts, no bloodwork is required as these are benign developmental anomalies that do not require laboratory monitoring or follow-up 1, 3
When cysts demonstrate complex features, the diagnostic approach focuses on imaging rather than bloodwork 1, 2

Serum CA19-9 and CEA cannot discriminate between simple hepatic cysts and mucinous cystic neoplasms (MCNs) with adequate accuracy 1, 2, 4
CA19-9 is elevated in up to 50% of patients with simple hepatic cysts or polycystic liver disease, making it non-specific 4
Serum CEA remains normal in simple cysts but is elevated in only 49% of cystadenomas and 75% of cystadenocarcinomas, with poor discriminatory ability (AUC 0.69) 4

If clinical features suggest infected hepatic cyst, complete blood count and C-reactive protein (CRP) should be ordered to assess for leukocytosis and inflammation 5
Blood cultures should be ordered if systemic infection is suspected 1
For polycystic liver disease, renal function tests (creatinine, BUN) should be ordered to screen for associated autosomal dominant polycystic kidney disease (ADPKD) 5

The EASL guidelines explicitly state with 100% consensus that CEA and CA19-9 in blood cannot be used to differentiate between hepatic cysts and MCNs 1, 2, 4
Complex cysts require MRI with contrast-enhanced sequences for definitive characterization, not bloodwork 1, 2, 5
TAG-72 (CA72-4) in cyst fluid may help distinguish simple cysts from MCNs, but this requires invasive sampling 1, 2, 4