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Test Code DSRCT Desmoplastic Small Round-Cell Tumor by Reverse Transcriptase PCR (RT-PCR)

Useful For

Supporting the diagnosis of desmoplastic small round-cell tumor

Additional Tests

Test ID Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill Only) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
EWSF EWSR1 (22q12), FISH, Ts Yes No

Testing Algorithm

This test is performed in conjunction with slide review. Additional testing may be performed after review by pathologist. Upon approval from the requesting clinician, PATHC / Pathology Consultation may be added, if determined to be appropriate.

Special Instructions

Method Name

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)/Gel Electrophoresis

Reporting Name

Desmo Small Round-Cell Tumor,RT-PCR

Specimen Type


Specimen Required

A pathology/diagnostic report including a brief history is required.


Specimen Type:

Container/Tube: Surgical Pathology Packaging Kit (T554) requested, but not required

Preferred: Formalin-fixed, paraffin-embedded (FFPE) tissue with a minimum of 5% tumor cell population

Acceptable: Unstained slides with a minimum of 5% tumor cell population; slides may be stained and/or scraped

Collection Instructions:

1. Process all specimens into FFPE blocks prior to submission.

2. If submitting slides, a minimum of ten, 4- to 5-micron thick, unstained slides are required.

Additional Information:

1. A quality specimen is essential for evaluation. Submit only tissue containing tumor cells; minimal tissue is required for evaluation.

2. Special stains performed outside Mayo Medical Laboratories and included with the case may be repeated and charged at the reviewing pathologist's discretion. Testing requested by the referring physician may not be performed if deemed unnecessary by Mayo Clinic pathologist.

Specimen Stability Information

Specimen Type Temperature Time
Varies Ambient (preferred)

Reference Values

An interpretative report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; Varies

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

81401-EWSR1/WT1 (t(11;22)) (eg, Ewing sarcoma/peripheral neuroectodermal tumor), translocation analysis, qualitative, and quantitative, if performed

88381-Microdissection, manual

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DSRCT Desmo Small Round-Cell Tumor,RT-PCR In Process


Result ID Test Result Name Result LOINC Value
54754 Result Summary 50397-9
54755 Result In Process
54756 Interpretation 69047-9
54757 Additional Information 48767-8
54758 Reason for Referral 42349-1
54759 Specimen 31208-2
54760 Source 31208-2
54761 Tissue ID 81178-6
54762 Released By 18771-6


1. Pathology/Cytology Information (T707) in Special Instructions

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

Pathology Test Request Form (T246) (

Oncology Test Request Form (T729) (