Immunohistochemistry INI-1 Test
Short Name: IHC INI-1 Test
Also known as: INI-1 Immunohistochemistry Test, SMARCB1 Expression Test, INI-1 Tumor Marker Test, INI-1 Loss of Expression Test, Rhabdoid Tumor IHC Panel Test
Immunohistochemistry INI-1 Test test available at DNA Labs India for ₹3,500. Uses Immunohistochemistry (IHC) on Tumor tissue in 10% Formal-saline OR Formalin fixed paraffin embedded (FFPE) block samples. Results in Block specimens: 5 working days. Tissue Biopsy: 5 working days. Large complex tissue: 7 working days. Samples received daily by 6:00 PM are processed the same day.. Free home collection in 300+ cities across India.
🩺 Medically Reviewed By
Dr Pasupathy Arumugam
Consultant Pathologist · Reg: 21521
Last reviewed: September 7, 2026
Overview
The Immunohistochemistry INI-1 Test is performed to detect the loss of INI-1 (SMARCB1) protein expression in tumor tissues, which serves as a diagnostic marker for specific aggressive malignancies including malignant rhabdoid tumors, epithelioid sarcomas, renal medullary carcinoma, and atypical teratoid/rhabdoid tumors. This test helps pathologists confirm tumor subtype, differentiate between similar-looking cancers, and guide treatment planning. It is also used to assess prognosis, as loss of INI-1 expression is generally associated with aggressive tumor behavior and may influence therapeutic strategies including targeted therapy approaches.
- Test Code
- 1008
- CPT Code
- 88342
- ICD Code
- D48.9
- Price
- ₹3,500
- Sample Type
- Tumor tissue in 10% Formal-saline OR Formalin fixed paraffin embedded (FFPE) block
- Result Time
- Block specimens: 5 working days. Tissue Biopsy: 5 working days. Large complex tissue: 7 working days. Samples received daily by 6:00 PM are processed the same day.
- Fasting Required
- No
- Method
- Immunohistochemistry (IHC)
Sample Collection
Provide a copy of the histopathology report, site of biopsy, and clinical history. Ensure the tissue specimen is properly fixed in 10% neutral buffered formalin or submitted as a formalin-fixed paraffin-embedded (FFPE) block.
Method: Tissue biopsy / Surgical resection specimen
Laboratory Analysis
Tissue is collected via biopsy or surgical resection under sterile conditions by the treating surgeon or pathologist. The specimen is immediately placed in 10% formal-saline for fixation.
Report Delivery
The fixed tissue is processed, embedded in paraffin wax, sectioned, and stained with anti-INI-1 antibody using immunohistochemistry. The stained slides are then examined by a qualified pathologist.
Timeline: Block specimens: 5 working days. Tissue Biopsy: 5 working days. Large complex tissue: 7 working days. Samples received daily by 6:00 PM are processed the same day.
Patient Instructions
About This Test
Who Should Get This Test
The Immunohistochemistry INI-1 Test is performed to detect the loss of INI-1 (SMARCB1) protein expression in tumor tissues, which serves as a diagnostic marker for specific aggressive malignancies including malignant rhabdoid tumors, epithelioid sarcomas, renal medullary carcinoma, and atypical teratoid/rhabdoid tumors. This test helps pathologists confirm tumor subtype, differentiate between similar-looking cancers, and guide treatment planning. It is also used to assess prognosis, as loss of INI-1 expression is generally associated with aggressive tumor behavior and may influence therapeutic strategies including targeted therapy approaches.
How to Prepare
- Submit tumor tissue in 10% Formal-saline or Formalin Fixed Paraffin Embedded (FFPE) block
- Ship specimen at room temperature
- Provide a copy of the histopathology report along with the specimen
- Mention the exact site of biopsy on the requisition form
- Include detailed clinical history including presenting symptoms and provisional diagnosis
- Ensure minimum fixation time of 6 hours and maximum of 48 hours in 10% neutral buffered formalin
Doctor's Notes
Reviewed by Dr Pasupathy Arumugam — MBBS, MD (Pathology) · Reg. No. 21521
"Loss of INI-1 expression is a critical diagnostic marker for identifying malignant rhabdoid tumors and epithelioid sarcomas. Early detection through immunohistochemistry allows for timely treatment planning and improved patient outcomes. I recommend this test whenever a rhabdoid morphology or epithelioid sarcoma is suspected on histopathological examination."
Last medically reviewed: September 7, 2026
Test Parameters & Specifications
Sample Stability
- Specimen received without formalin fixation
- Completely necrotic tissue with no viable tumor cells
- Specimen without proper labeling or clinical history
- Tissue fixed in inappropriate fixatives other than 10% neutral buffered formalin
- Specimen received in dried condition or without proper container
Understanding Your Results
Nuclear staining is observed in tumor cells, indicating normal expression of the INI-1 protein. This suggests that SMARCB1 gene is intact and does not support a diagnosis of malignant rhabdoid tumor or related SMARCB1-deficient neoplasms.
Tumors with retained INI-1 expression are less likely to be malignant rhabdoid tumors, epithelioid sarcomas, or renal medullary carcinoma. Other diagnoses should be considered based on morphology and clinical context.
Complete absence of nuclear staining in tumor cells while internal controls (endothelial cells, lymphocytes, stromal cells) show positive staining, indicating loss of INI-1 protein expression.
Loss of INI-1 expression is a hallmark of malignant rhabdoid tumors, epithelioid sarcomas (proximal and distal types), renal medullary carcinoma, and atypical teratoid/rhabdoid tumors. Correlation with histomorphology, clinical presentation, and molecular studies is recommended for definitive diagnosis.
Consult your doctor or oncologist immediately if you notice any unexplained lump or swelling, experience persistent pain in any body region, have unexplained weight loss, notice changes in bowel or bladder habits, or experience chronic fatigue. If your treating physician has recommended an INI-1 test based on biopsy findings, please schedule the test promptly as early diagnosis is critical for treatment planning in aggressive tumors.
Limitations
- ⚠This test is qualitative and does not quantify the degree of INI-1 expression loss
- ⚠Loss of INI-1 expression is supportive but not solely diagnostic; correlation with histopathology, clinical findings, and molecular studies is essential
- ⚠Rare tumors may show partial or mosaic loss of INI-1 expression, making interpretation challenging
- ⚠This test detects protein-level loss and does not identify the specific genetic alteration in the SMARCB1 gene; additional molecular testing may be required
- ⚠Sampling error from small biopsies may not represent the entire tumor
Risks & Considerations
- ●No direct risk to the patient from the test itself, as it is performed on an already collected tissue specimen
- ●Biopsy collection (if not already performed) carries minor risks including bleeding, infection, and discomfort at the biopsy site
- ●False negative results are possible due to suboptimal fixation, antigen masking, or sampling error
- ●False positive internal controls failure may rarely occur with technical errors in the staining procedure
Interfering Factors
- ●Inadequate fixation of the tissue specimen may affect antigen preservation
- ●Excessive fixation time in formalin can lead to antigen masking and false negative results
- ●Necrotic or heavily calcified tumor tissue may yield unreliable staining
- ●Decalcification procedures may reduce antigenicity of INI-1 protein
- ●Improper storage of FFPE blocks over prolonged periods may degrade antigen quality
Compare With Similar Tests
| Test | Immunohistochemistry INI-1 Test | INI-1 FISH / Molecular Testing | SMARCB1 Gene Sequencing |
|---|---|---|---|
| Comparison | Immunohistochemistry INI-1 Test | While IHC detects protein-level loss, FISH and molecular testing identify specific SMARCB1 gene deletions or mutations at the DNA level. Molecular testing is more expensive but provides detailed genetic information. | Gene sequencing identifies point mutations in the SMARCB1 gene and can detect alterations that may not result in complete protein loss detectable by IHC. Both tests complement each other for comprehensive diagnosis. |
Frequently Asked Questions
What is the Immunohistochemistry INI-1 Test?
Why is the INI-1 Test recommended by doctors?
What sample is required for the INI-1 Test?
What does a negative INI-1 result mean?
What does a positive INI-1 result mean?
What is the cost of the Immunohistochemistry INI-1 Test in India?
Is home sample collection available for the INI-1 Test?
How long does it take to get the INI-1 Test results?
Is fasting required for the Immunohistochemistry INI-1 Test?
Which cancers are associated with loss of INI-1 expression?
Is the INI-1 Test covered under government health schemes like PMJAY or CGHS?
How is the INI-1 Test different from SMARCB1 gene sequencing?
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