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HelpTest Code PTH-O PTH, Intact - Other Fluids
Useful For
This test is an adjunct to cytology examination of fine-needle aspiration specimens to confirm or exclude presence of parathyroid tissue in the biopsied area.
Synonyms/Keywords
FNA, Fine Needle Aspirate, Parathyroid Hormone, Fluid, Cyst, PTH
Specimen Requirements
| Fasting Required | Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) | Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|---|
| No | Body Fluid | 1.0 mL | 0.7 mL | 0.4 mL |
Collection/Processing Instructions
Indicate the fluid type.
If the specimen shows visible blood or tissue contamination, centrifuge the specimen. Transfer the supernatant to a new plastic tube.
Maintain specimens refrigerated and freeze if testing not performed within 4 hours. Avoid freeze and thaw of samples. Only one freeze and thaw cycle acceptable.
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Body Fluid | Ambient | 4 hours |
| Refrigerate | 8 hours | |
| Frozen at -20 deg Celsius | 3 months | |
| Frozen at -70 deg Celsius | > 3 months | |
| Fine Needle Aspirate | Ambient | 24 hours |
| Refrigerate | 7 days | |
| Frozen at -20 deg Celsius | 3 months | |
| Frozen at -70 deg Celsius | > 3 months |
Rejection Criteria
Highly viscous specimens.
Interferences
Immunometric assays can be subject to interferences such as "hook effect" at very high analyte concentrations (false-low results) and heterophilic antibody interference (false-high results). If the clinical picture does not fit the laboratory result, these possibilities should be considered.
Interpretations
PTH analysis from fine-needle aspiration biopsies (FNAB) is popularly used to discriminate thyroid tissues from enlarged parathyroid glands and also to facilitate parathyroid localization prior to surgery. Specimen collection is critical for the performance of the assay and the needle should be rinsed with a minimal volume. Comparing the results of the PTH rinse material with serum PTH is highly recommended. An elevated PTH in the serum could falsely elevate PTH in the washings if the rinse is contaminated with blood. In these cases, only PTH values significantly higher than the serum should be considered as true positives.
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| Marshfield and Eau Claire |
No reference ranges are available.
This test cannot distinguish between benign and malignant parathyroid tissue. |
Marshfield Labs Performing Department
Marshfield Labs Chemistry
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Eau Claire | Monday through Friday | Less than 2 hours | Two-site Sandwich Immunoassay using Direct Chemiluminometric Technology/Siemens Centaur |
| Marshfield | Monday through Sunday | Less than 2 hours | Two-site Sandwich Immunoassay using Direct Chemiluminometric Technology/Siemens Centaur |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 83970 |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 83970 |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | PTH, Intact - Other Fluids |