30 May 2021
: Case report 
Systemic IgG4-Related Disease Masquerading as Cholangiocarcinoma: A Case Report Underscoring the Importance of Medical History
Challenging differential diagnosis, Rare disease, Educational Purpose (only if useful for a systematic review or synthesis)
Benjamin P. Gummlich1ABDEF*, Philipp Ströbel2BDE, Ali Seif Amir Hosseini3BD, Albrecht Neesse1DE, Volker Ellenrieder1D, Harald Schwörer1ABDEFDOI: 10.12659/AJCR.930729
Am J Case Rep 2021; 22:e930729
Table 1. Serum parameters found to be abnormal on patient’s admission.
| Parameter | Unit | Reference range | Results |
|---|---|---|---|
| Total bilirubin | µmol/L | <20.5 | |
| Conjugated bilirubin | µmol/L | <8.55 | |
| AP | U/L | 40–150 | |
| γGT | U/L | 12–64 | |
| AST | U/L | <35 | |
| ALT | U/L | <45 | |
| IgG4 | g/L | 0.0300–2.0100 | |
| HDL | mg/dL | >40 | |
| Triglycerides | mg/dL | <200 | |
| CRP | mg/L | <5 | |
| Protein | g/dL | 6.6–8.3 | 7 |
| Albumin | % | 55.8–66.1 | |
| α-globulin | % | 2.9–4.9 | |
| α-globulin | % | 7.1–11.8 | |
| β-globulin | % | 4.7–7.2 | 5.9 |
| β-globulin | % | 3.2–6.5 | |
| γ-globulin | % | 11.1–18.8 | |
| IgG | g/L | 5.4–18.2 | 8,9 |
| IgM | g/L | 0.22–2.93 | 2.6 |
| IgA | g/L | 0.63–4.84 | 2.0 |
| ALT – alanine aminotransferase; AP – alkaline phosphatase; AST – aspartate transaminase; CRP – C-reactive protein; γGT – gamma-glutamyl transpeptidase; HDL – high-density lipoprotein. | |||