Initial diagnostic phase

Initial diagnostic phase

• NICE suggest that the following investigations to patients with metastatic disease of unknown origin (MUO) should be offered, as clinically appropriate, guided by the patient's symptoms:
  
  
  • comprehensive history and physical examination including breast, nodal areas, skin, genital, rectal and pelvic examination
    
    
  • full blood count; urea, electrolytes and creatinine; liver function tests; calcium; urinalysis; lactate dehydrogenase
    
    
  • chest X-ray
    
    
  • myeloma screen (when there are isolated or multiple lytic bone lesions)
    
    
  • symptom-directed endoscopy
    
    
  • computed tomography (CT) scan of the chest, abdomen and pelvis
    
    
  • prostate-specific antigen (PSA) in men
    
    
  • cancer antigen 125 (CA125) in women with peritoneal malignancy or ascites
    
    
  • alpha-fetoprotein (AFP) and human chorionic gonadotrophin (hCG) (particularly in the presence of midline nodal disease)
    
    
  • testicular ultrasound in men with presentations compatible with germ-cell tumours
    
    
  • biopsy and standard histological examination, with immunohistochemistry where necessary, to distinguish carcinoma from other malignant diagnoses.

Reference:

• 1) NICE (April 2023). Metastatic malignant disease of unknown primary origin - Diagnosis and management of metastatic malignant disease of unknown primary origin