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Test ID SPBX Epidermal Nerve Fiber Density Consultation, Varies

Shipping Instructions

Transport specimen per instructions on the Epidermal Nerve Fiber Density Instructions (T703).

Necessary Information

The following information is required:

1. Epidermal Nerve Fiber Density Patient Information (T702) is required, containing the following information:

-Patient name and date of birth

-Name and phone number of the referring pathologist or ordering physician

-Anatomic site and collection date

2. Additional clinical information:

-Clinical notes

-Nerve Conduction Studies/Electromyography results, if performed


All requisition and supporting information must be submitted in English.

Specimen Required


Specimen Type: Skin punch biopsy tissue

Supplies: A Skin Punch Biopsy Kit containing fixatives, buffer, and cryoprotectant is required (no substitutions accepted). For ordering information, call 507-284-8065.

Preferred source: Distal leg, mid-thigh, dorsal foot, and lower abdomen

Collection Instructions:

1. The standard biopsy for evaluating distal small fiber sensory neuropathy includes two 3-mm skin punch biopsies from the same side of the body.

2. Prepare and transport specimen per instructions on the Epidermal Nerve Fiber Density Instructions (T703)

Specimen Stability: Refrigerated (preferred)/Ambient



Specimen Type: Slides

Additional Information:

1. Slides reacted with PGP 9.5, using a PGP 9.5 protocol for visualizing epidermal nerve fibers, are required.

2. Hematoxylin and eosin-stained slides and Congo red-stained slides are optional.

Specimen Stability: Ambient (preferred)/Refrigerated


Specimen Type: Tissue block and PGP9.5-reacted slides

Additional Information:

1. Slides reacted with PGP 9.5, using a PGP 9.5 protocol for visualizing epidermal nerve fibers, are required.

2. Tissue block may be used to create hematoxylin and eosin-stained slides and Congo red-stained slides.

Note: Visualization of epidermal nerve fibers cannot be done on paraffin blocks.

Specimen Stability: Ambient (preferred)/Refrigerated

Useful For

Investigating polyneuropathies

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SS2PC SpecStain, Grp II, other No, (Bill Only) No
COSPC Consult, Outside Slide No, (Bill Only) No
CUPPC Consult, w/USS Prof No, (Bill Only) No
CRHPC Consult, w/Comp Rvw of His No, (Bill Only) No
MANPC Morph Analysis, Nerve No, (Bill Only) No
LV4RP Level 4 Gross and Microscopic, RB No, (Bill Only) No
CSPPC Consult, w/Slide Prep No, (Bill Only) No
EM Electron Microscopy Yes No
IHPCI IHC Initial No, (Bill Only) No

Testing Algorithm

A battery of enzyme histochemical stains or immunostains are performed; other tests can be performed, as indicated, at an additional charge.


Wet tissue for consultation: When adequately prepared tissue is provided, routine testing will include PGP 9.5 (protein gene product 9.5) immunostain, morphometric analysis, Congo red stain, and hematoxylin and eosin stain. PGP 9.5 reactions cannot be done on previously embedded tissue, eg, paraffin blocks, epoxy blocks.


Slides and blocks sent for consultation must include PGP 9.5-reacted sections:

Special stains and studies performed on the case should be sent with the case for review. In order to determine an accurate diagnosis, some of these stains or studies may be deemed to warrant repeat testing, at an additional charge, at the discretion of the reviewing Mayo Clinic neuromuscular pathologist. In addition, testing requested by the referring physician (immunostains, molecular studies, etc) may not be performed if deemed unnecessary by the reviewing Mayo Clinic neuromuscular pathologist. For all consultations, ancillary testing necessary to determine a diagnosis is ordered at the discretion of the Mayo Clinic neuromuscular pathologist. An interpretation, which includes an evaluation of the specimen and determination of a diagnosis, will be provided within a formal pathology report.


For more information see Pathology Consultation Ordering Algorithm.

Method Name

Calculation of Epidermal Nerve Fiber Density

Reporting Name

Epidermal Nerve Fiber Density

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred)

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday through Friday

Report Available

7 to 14 days: Cases requiring additional material or ancillary testing may require additional time

Performing Laboratory

Mayo Clinic 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 US Food and Drug Administration.

CPT Code Information

88305 (if appropriate)

88313 (if appropriate)

88321 (if appropriate)

88323 (if appropriate)

88323-26 (if appropriate)

88325 (if appropriate)

88348 (if appropriate)

88356 (if appropriate)

88342 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SPBX Epidermal Nerve Fiber Density In Process


Result ID Test Result Name Result LOINC Value
601780 Interpretation 59465-5
601791 Participated in the Interpretation No LOINC Needed
601792 Report electronically signed by 19139-5
601793 Addendum 35265-8
601794 Gross Description 22634-0
601795 Material Received 81178-6
601824 Case Number 80398-1
601913 Disclaimer 62364-5