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Test Code 4993 Electron Microscopy

Reporting Name

Electron Microscopy

Useful For

Identifying tumor


Diagnosing medical disorders such as storage diseases, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and primary ciliary dyskinesia

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Tissue source required for testing to be performed.



1. Electron Microscopy Patient Information in Special Instructions

2. Electron Microscopy Procedures of Handling Specimens for Electron Microscopy in Special Instructions

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

4. If not ordering electronically, complete, print, and send a Pathology Test Request Form (T246) with the specimen (


A completed Patient Information Sheet is required for all Electron Microscopy Consultations (see Special Instructions)


Collect specimen according to the instructions in Electron Microscopy Procedures of Handling Specimens for Electron Microscopy in Special Instructions. Do not place on ice, dry ice, or freeze.


Submit only 1 of the following specimen types:


Specimen Type: Fixed wet tissue

Container/Tube: Electron Microscopy Kit (Supply T660) or leak-proof container

Specimen Volume: Entire specimen

Additional Information: 70012 / Pathology Consultation may be added if deemed necessary by the reviewing pathologist.


Specimen Type: Whole blood (Neuronal Ceroid Lipofuscinosis-NCL only)

Container/Tube: Electron Microscopy Kit (Supply T660), green top (sodium heparin), or yellow top (ACD [solution B])

Specimen Volume: 5 mL

Collection Instructions: Do not transfer blood to other containers.

Additional Information: Specimen must arrive within 48 hours of draw.

Specimen Minimum Volume


Specimen Stability Information

Specimen Type Temperature Time
Varies Ambient (preferred)

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; Varies

Test Classification

This test uses a standard method. Its performance characteristics were 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


LOINC Code Information

Result ID Test Result Name Result LOINC Value
18296 Accession Number 57723-9
18297 Referring Pathologist/Physician 46608-6
18298 Ref Path/Phys Address 74221-3
18299 Place of Death: 21987-3
18300 Date and Time of Death: 81956-5
18301 Date of Autopsy: 75711-2
18302 Specimen: 31208-2
18303 Material: In Process
18304 Tissue Description: 22634-0
18305 Microscopic Description: No LOINC Needed
18306 Clinical History: 22636-5
18307 Final Diagnosis: 34574-4
18999 Final Diagnosis: 34574-4
18308 Comment: 48767-8
18309 Revision Description: In Process
18310 Signing Pathologist: 19139-5
18311 Special Procedure: 30954-2
18312 SP Signing Pathologist: 19139-5
18313 *Previous Report Follows* No LOINC Needed
18314 Addendum: 35265-8
19191 Addendum Comment: 22638-1
18315 Addendum Pathologist: 19139-5

Testing Algorithm

For nontumorous renal specimens, see 70064 / Renal Pathology Consultation, Wet Tissue for Electron Microscopy.


For platelet disorders, see PTEM / Platelet Transmission Electron Microscopic Study.


For muscle specimens, see MPCT / Muscle Pathology Consultation.


For CADASIL genetic mutation testing on blood, contact Mayo Medical Laboratories.

Method Name

Electron Microscopy