Table 5 Initial investigations in classical fever of unknown origin
From: Undifferentiated epithelioid sarcoma presenting as a fever of unknown origin: a case report
Diagnostic test | Potential diagnostic utility |
|---|---|
Initial investigations | |
CBC with differential and smear | - Neutropenia to determine breadth of possible infection, cytopenias suggesting bone marrow involvement |
Renal function | - Glomerulonephritis |
Liver enzymes and LFTs | - Hepatic or cholestatic etiologies |
ESR and CRP | - Markers signifying an inflammatory process |
Thyroid function | - Thyrotoxicosis |
HIV antibody | - HIV and potential for opportunistic infections |
Blood cultures | - Bacteremia or fungemia |
Urine analysis and microscopy | - UTI, glomerulonephritis, or vasculitis |
CXR | - Pneumonia, miliary TB, sarcoidosis, or malignancy |
Investigations based on diagnostic clues from initial workup | |
Echocardiography | - Potential endocarditis |
CT | - Abscesses, other infections, or malignancy |
Indium-111-WBC scan | - To localize any sites of inflammation |
FDG-PET/CT | - Careful localization of infection, malignancy, vasculitis, or sarcoidosis |
Lymph node biopsy | - Malignancy or infection |
Liver biopsy | - Malignancy, infection, or autoimmune diseases |
Bone marrow biopsy | - Hematologic malignancy |
Temporal artery biopsy | - Giant cell arteritis |