Salvage
Sampling
Sarcoma
Scans (radioisotope)
Screening
Second-look surgery
Seizure (convulsion)
Selective angiography
Sepsis (septicemia, bacteremia)
Serum protein electrophoresis (SPEP)
Shingles (see Herpes zoster)
Sigmoidoscopy
Sodium
Sonography
Sphincter
Spleen
Sputum
Squamous cell (epidermoid) carcinoma
Staging
Stereotactic needle biopsy
Steroids
Stoma
Stomatitis
Stool
Stool for occult blood
Superior vena cava
Suppository
Systemic disease