Test Code RPCWT Renal Pathology Consultation, Wet Tissue
Shipping Instructions
1. Advise shipping specimens in Styrofoam transportation coolers to avoid extreme hot or cold temperatures to ensure specimens are received at required specimen stability temperature.
2. Attach the green pathology address label included in the kit to the outside of the transport container.
Necessary Information
Note: Requisitions for this procedure cannot be processed unless the listed necessary information is supplied.
1. All requisitions must be labeled with:
-Patient name
-Date of birth
-Medical record number
-Ordering physician
-Anatomic site
-Collection date
2. All specimens must be labeled with:
-Two patient identifiers (first and last name, date of birth or medical record number).
-Anatomic site
Specimen Required
Specimen Type: Tissue
Supplies: Renal Biopsy Kit (T231)
Source: Kidney
Specimen Volume: Entire specimen
Collection Instructions: Collect specimens according to the instructions in Renal Biopsy-Procedures of Handling Tissue for Light Microscopy, Immunohistology, and Electron Microscopy in Special Instructions.
Forms
1. Renal Biopsy Patient Information in Special Instructions
2. Renal-Biopsy Procedures of Handling Tissue for Light Microscopy, Immunohistology, and Electron Microscopy in Special Instructions
3. If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Useful For
Evaluating and managing patients with kidney disease
Following the progression of known renal disease or response to therapy
Determining the cause of dysfunction in the transplanted kidney (allograft)
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
LV4RP | Level 4 Gross and Microscopic, RB | No | No |
EMR | EM, Renal Biopsy | No | No |
SS2PC | SpecStain, Grp II, other | No | No |
IFPCI | IF Initial | No | No |
IFPCA | IF Additional | No | No |
Testing Algorithm
The Renal Pathology Consultation is performed by a Mayo Clinic renal pathologist and entails the performance of appropriate procedures and stains based on the material received, patient information and specific findings on the case in order to determine a diagnosis. Optimal/standard diagnostic interpretation of a medical kidney biopsy requires integration of the light microscopy, immunofluorescence, and electron microscopy findings together with the clinical and laboratory data for the patient. Published standards by the Renal Pathology Society are followed for the diagnostic evaluation and reporting of non-neoplastic renal disease.(1)
Light Microscopy:
Wet/unprocessed tissue submitted for light microscopy routinely includes the preparation of stains, which include hematoxylin and eosin (H and E), periodic acid Schiff (PAS), Masson trichrome, and Jones methenamine silver stains.
Immunofluorescence:
Wet/unprocessed tissue submitted for immunofluorescence may include the following stains in order to render an accurate diagnosis. These stains include: IgA, IgG, IgM, C1q, C3, albumin, fibrinogen, kappa light chain, and lambda light chain stains with C4d added if the biopsy is an allograft.
The IgG subtypes (IgG1, IgG2, IgG3, IgG4) are typically only utilized if the biopsy shows features suspicious for a monoclonal/monotypic deposition process involving IgG.
Alport (collagen IV, alpha 2 and alpha 5) staining is performed in the setting of biopsy findings that are consistent with hereditary nephritis/Alport syndrome.
Phospholipase A2 Receptor (PLA2R) staining is performed in the setting of membranous nephropathy/glomerulonephritis to aid in determining whether it is most likely primary/idiopathic or secondary.
Paraffin-Based Immunofluorescence Stains:
The paraffin-based immunofluorescence stains listed above would only be utilized in the special circumstance when there is no tissue or inadequate tissue available for standard immunofluorescence or if there are findings that raise concern for so-called "masked deposits"
Electron Microscopy:
Wet/unprocessed tissue submitted for electron microscopy will be processed for transmission electron microscopy. A formal interpretive report is issued, incorporating the findings from all tests performed for diagnostic purposes.
See Pathology Consultation Ordering Algorithm in Special Instructions.
Special Instructions
Method Name
Pathology Consultation
Reporting Name
Renal PathologySpecimen Type
Kidney BiopsySpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Kidney Biopsy | Ambient (preferred) | ||
Refrigerated |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
The Mayo Renal Pathology service is staffed by board-certified pathologists who have a special interest in non-neoplastic diseases of the kidney.
Kidney biopsy has proven to be of value in the clinical evaluation and management of patients with kidney disease, including acute and chronic renal insufficiency, nephrotic syndrome, nephritic syndrome, proteinuria and hematuria, and in the overall management of renal transplant recipients.
Optimal interpretation of a kidney biopsy requires integration of clinical and laboratory results with light microscopic, immunofluorescent histology, and electron microscopy findings.
Reference Values
An interpretive report will be provided.
Day(s) and Time(s) Performed
Monday through Friday
Rush (same day as receipt) interpretation is available on Saturday and holidays for clinically emergent cases (eg, acute renal failure, rapidly progressive glomerulonephritis, acute kidney allograft dysfunction) but requires advanced notification and approval by a Mayo renal pathologist.
Analytic Time
Routine cases: 1 day. Electron microscopy: 2 to 10 daysPerforming Laboratory

CPT Code Information
88305 (If appropriate)
88348 (If appropriate)
88313 (If appropriate)
88346 (If appropriate)
88350 (If appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RPCWT | Renal Pathology | 65757-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
71219 | Interpretation | 60570-9 |
71220 | Participated in the Interpretation | No LOINC Needed |
71221 | Report electronically signed by | 19139-5 |
71222 | Addendum | 35265-8 |
71223 | Gross Description | 22634-0 |
71224 | Material Received | 85298-8 |
71615 | Disclaimer | 62364-5 |
71846 | Case Number | 80398-1 |