Lab Dept:


Test Name:

INHIBIN A Tumor Marker

General Information

Lab Order Codes:




CPT Codes:

86336 – Inhibin A

Test Includes:

Inhibin A tumor marker level reported in pg/mL.


Test Indications:

As an aid in the diagnosis of granulosa cell tumors of the ovary when used in combination with inhibin b. Monitoring of patients with granulosa cell tumors and epithelial mucinous-type tumors of the ovary known to excrete inhibin a.

Lab Testing Sections:

Chemistry - Sendouts

Referred to:

Mayo Medical Laboratories (MML Test: INHA)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

1 - 2 days: Performed Monday-Saturday

Special Instructions:



Specimen Type:



Red top tube

Draw Volume:

1.8 mL (1.5 mL) blood

Processed Volume:

0.6 mL (0.5 mL) serum


Routine venipuncture


Special Processing:

Lab Staff: Centrifuge specimen, remove serum aliquot into a screw-capped round bottom plastic vial. Store and ship at refrigerated temperature. Label specimen appropriately. Forward promptly.

Patient Preparation:


Sample Rejection:

Mislabeled or unlabeled specimens; gross hemolysis




<11 years:

<4.7 pg/mL

11 – 17 years:

<97.5 pg/mL


<97.5 pg/mL


<2.1 pg/mL


All ages:

<2.0 pg/mL

Interpretation: Inhibin A levels are elevated in approximately 70% of patients with granulosa cell tumors and in approximately 20% of patients with epithelial ovarian tumors. A normal inhibin A level does not rule-out a mucinous or granulosa ovarian cell tumor. Testing for inhibin B in these cases might be informative as a higher proportion of mucinous or granulosa ovarian cell tumors will have an elevated inhibin B level.

For monitoring of patients with known ovarian cancer, inhibin A levels decrease shortly after surgery. Elevations of inhibin A after treatment are suggestive of residual, recurrent, or progressive disease. In patients with recurrent disease, inhibin A elevation seems to be present earlier than clinical symptoms. Patients in remission show normal levels of inhibin A.

Critical Values:



Do not interpret serum inhibin levels as absolute evidence of the presence or the absence of malignant disease. Use results in conjunction with information from the clinical evaluation of the patient and other diagnostic procedures.

Inhibin values fluctuate during the menstrual cycle. Inhibin levels in premenopausal women should be interpreted with caution.

Tumor markers are not specific for malignancy and values may vary by testing methodology. The same method should be used to serially monitor patients.

Some patients who have been exposed to animal antigens, either in the environment or as part of treatment or imaging procedures, may have circulating antianimal antibodies present. These antibodies may interfere with the assay reagents to produce unreliable results.


Sequential 2-step Immunoenzyme Assay


Mayo Medical Laboratories Web Page (March 2013)