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Test Code MPNCM Myeloproliferative Neoplasm (MPN), CALR with Reflex to MPL

Shipping Instructions

Specimen must arrive within 7 days (168 hours) of collection.

Necessary Information

The following information is required:

Pertinent clinical history

Clinical or morphologic suspicion

Date of collection

Specimen source

Specimen Required

Submit only 1 of the following specimens:


Specimen Type: Blood

Container/Tube: EDTA (Lavender) or ACD-B (yellow top)

Specimen Volume: 3 mL

Specimen Stability: Ambient (preferred)/Refrigerate

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

3. Label specimen as blood.


Specimen Type: Bone marrow aspirate

Container/Tube: EDTA (Lavender) or ACD-B (yellow top)

Specimen Volume: 2 mL

Specimen Stability: Ambient (preferred)/Refrigerate

Collection Instructions:

1. Invert several times to mix specimen.

2. Send specimen in original tube.

3. Label specimen as bone marrow.


Specimen Type: Extracted DNA from blood or bone marrow

Container/Tube: 1.5 to 2 mL tube

Specimen Volume: Entire specimen

Specimen Stability: Frozen (preferred)/Refrigerate/Ambient

Collection Instructions:

1. Indicate volume and concentration of DNA

2. Label specimen as extracted DNA from blood or bone marrow.


If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request Form (T726) with the specimen (

Useful For

Aiding in the distinction between a reactive cytosis and a myeloproliferative neoplasm when JAK2V617F testing result is negative

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
MPNML MPL Exon 10 Sequencing, Reflex No, (bill only) No

Testing Algorithm

This test reflexively evaluates for mutations in the CALR and MPL genes commonly associated with BCR/ABL1-negative myeloproliferative neoplasms. The testing sequence is based on the reported frequency of gene mutations in this disease group. It is usually ordered when a JAK2 V617F result is known to be negative. Initial testing evaluates for the presence of the CALR indels. If out-of-frame CALR indels are detected, the testing algorithm ends. If the CALR result is negative or an in-frame CALR indel is identified, then testing proceeds, at an additional charge, to evaluate for mutations in exon 10 of the MPL gene by Sanger sequencing. An integrated report is issued with the summary of test results.


The following algorithms are available in Special Instructions:

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

Method Name

Polymerase Chain Reaction (PCR) and Fragment Analysis

Reporting Name

MPN (CALR, MPL) Reflex

Specimen Type


Specimen Minimum Volume

Blood/Bone marrow: 0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies 7 days

Reject Due To


Mild OK; Gross reject






Paraffin embedded bone marrow aspirate clot or biopsy blocks, slides, paraffin shavings, heparin, moderately to severely clotted

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

7 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

81219-CALR (calreticulin) (eg, myeloproliferative disorders), gene analysis, common variants in exon 9


81403-MPL (myeloproliferative leukemia virus oncogene, thrombopoietin receptor, TPOR) (eg, myeloproliferative disorder), exon 10 sequence (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MPNCM MPN (CALR, MPL) Reflex In Process


Result ID Test Result Name Result LOINC Value
42393 MPNCM Reflex Result 82939-0
MP036 Specimen Type 31208-2
42392 Final Diagnosis 50398-7