CPT 82270 is when the clinician provides the patient with a triple card to obtain 3 (separate) cards for a stool sample from three consecutive BMs. Once complete the patient returns the cards to the lab.
The lab tech applies a reagent which contains hydrogen peroxide to the fecal smear on the card. If the card turns an intense blue it is positive, indicating there is blood in the stool.
CPT 82274 the clinician may take the sample or specimen via digital rectal exam and prvide a (single) smear to the lab. The clinician can also provide the patient a card for 3 separate smears and have the patient submit it to the lab
The lab tech performs an immunoassay test, mixing a reagent containing the antibody antihuman hemoglobin with the fecal sample. The clumping, or binding reaction a.k.a, agglutination is measured.
The difference is CPT 82270 is ordered specifically to screen for possible colorectal caner in patients who are asymptomatic. The testing utilizes peroxidase.
CPT 82274 is ordered in the absence of symptoms to screen for colorectal cancer or as a diagnostic test to rule out lower gastrointestinal bleeding in the event a patient is experiencing symptoms, such as, abdominal pain or dark tarry stools. Testing utilizes hemoglobin determination.
This test may be ordered in place of a peroxidase in range (82270-82272).
82270--Blood, occult, by peroxidase activity
82274-immunoassay, antihuman hemoglobin determination
Hope that helps,
Shandell