IHC Marker - HMB45 Test
About IHC Marker - HMB45 Test
| Field | Value |
|---|---|
| Also Known As | HMB-45, HMB45 IHC, Human Melanoma Black 45, Melanoma Marker HMB45, gp100 antibody stain |
| Sample Type | Tissue biopsy (formalin-fixed, paraffin-embedded tissue block) |
| Fasting Required | No |
| Report Time | 7 days |
| Recommended For | All ages and genders; ordered when melanoma or melanocytic tumours are suspected |
| Price | Starting at ₹1,920 |
What is an IHC Marker - HMB45 Test?
The IHC Marker - HMB45 test is an immunohistochemistry (IHC) test that uses a specialised antibody to detect a protein called gp100 (also known as Pmel17) in tissue samples. Doctors order this test when they suspect melanoma or other melanocytic tumours — that is, tumours arising from pigment-producing cells called melanocytes. Also known as Human Melanoma Black 45 or the HMB45 IHC stain, this test is performed on a tissue sample taken through a biopsy procedure.
What Does an IHC Marker - HMB45 Test Measure?
This test examines tissue at a cellular level to find out whether the gp100 protein is present. The table below explains what the test evaluates.
| Component | What it Detects | Why it Matters |
|---|---|---|
| HMB45 antigen (gp100/Pmel17) | A pre-melanosome protein found in immature and activated melanocytes | Confirms the presence of melanocytic cells in the tissue sample |
| Cytoplasmic staining pattern | The location and extent of the colour change produced in tumour cells | Helps the pathologist assess how many cells express the marker and how strongly |
| Reactivity profile | Which cell types bind to the HMB45 antibody | Distinguishes melanocytic lesions from other tumour types |
The test is qualitative. Results are reported as positive or negative, along with details about staining intensity and the proportion of cells stained. Approximately 90% of melanomas react with the HMB45 antibody.
Why is an IHC Marker - HMB45 Test Done?
This test is ordered when a tissue sample needs to be examined for melanocytic differentiation. Below are the most common reasons a doctor may request it.
Common Symptoms That May Require This Test
A doctor may recommend a biopsy and subsequent HMB45 IHC testing when any of the following skin changes are noticed:
- A new spot on the skin or an existing mole changing in size, shape, or colour
- Unusual moles, lumps, or blemishes that look or feel different from surrounding skin
- A lesion that bleeds or oozes without an obvious cause
- Itching, pain, or tenderness in a skin lesion
- A darkly pigmented or discoloured area that is growing
- Sores that do not heal over a normal period of time
- Changes in the appearance of skin around the eye or within the eye (conjunctival or choroidal changes)
Conditions This Test Can Help Detect
The IHC Marker - HMB45 test is used to help identify a range of melanocytic and related conditions:
- Primary cutaneous malignant melanoma
- Metastatic melanoma, including amelanotic (non-pigmented) variants
- Benign melanocytic naevi (moles) and their subtypes
- Conjunctival and choroidal (eye) melanomas
- Perivascular epithelioid cell tumours (PEComas), including angiomyolipoma and lymphangioleiomyomatosis
- Clear cell sarcoma and pigmented schwannoma
- Micrometastases in sentinel lymph node biopsies
How to Prepare and What to Expect
No special preparation is needed for the IHC Marker - HMB45 test procedure itself, but there are a few things to keep in mind before your appointment.
Do You Need to Fast?
No fasting is required for this test. The test is performed on a tissue sample, not a blood or urine sample, so dietary restrictions do not apply.
Practical Tips Before Your Test
Here are a few steps to help ensure your visit goes smoothly:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test
- Inform your doctor about all medications and supplements you are currently taking
- If a biopsy is required as part of the visit, follow your doctor's wound care instructions beforehand
- Wear loose, comfortable clothing that allows easy access to the area being examined
- Ask your doctor in advance what type of biopsy will be performed so you know what to expect
Step-by-Step Procedure
The IHC Marker - HMB45 test procedure involves the following steps:
- A tissue sample is collected by a healthcare professional through a biopsy. Depending on the lesion, this may be a surgical excision, punch biopsy, or core needle biopsy. Local anaesthesia is typically used to minimise discomfort.
- The collected tissue is preserved using formalin (a chemical fixative) and then embedded in paraffin wax. This creates a firm block that protects the tissue structure during processing.
- The paraffin-embedded block is cut into very thin slices and placed on glass microscope slides for staining.
- The HMB45 antibody is applied to the tissue sections. If the gp100 protein is present in the cells, the antibody binds to it.
- A detection system is added that produces a visible colour change, typically a brown or red stain, showing where and how strongly the protein is expressed.
- A pathologist examines the stained slides under a microscope and prepares a written report. The tissue block is stored at room temperature and dispatched to the laboratory for processing.
Factors That Can Affect Accuracy
Several factors can influence the reliability of results:
- Poor tissue preservation or insufficient sample size may lead to inconclusive findings
- Fixation time in formalin affects how well the antibody binds to the target protein
- The quality of the antibody reagents and laboratory controls used during processing
- Variation in how pathologists interpret staining patterns, particularly in borderline cases
- Certain melanoma subtypes, such as spindle cell and desmoplastic melanomas, may not react with HMB45
Understanding Your IHC Marker - HMB45 Test Results
Results from this test should always be reviewed by a qualified pathologist and discussed with your treating doctor alongside your full clinical picture. The table below outlines how findings are generally interpreted.
| Result | Interpretation |
|---|---|
| Positive | HMB45 antigen detected; cytoplasmic staining seen in tumour cells, indicating melanocytic differentiation |
| Negative | No HMB45 antigen detected; melanocytic differentiation not confirmed by this marker alone |
Disclaimer: These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
HMB45 is not used as a standalone diagnostic marker. It is typically interpreted alongside other melanocytic stains such as S100. When used in combination, these markers can significantly improve diagnostic accuracy, particularly in sentinel lymph node biopsies.
Some melanoma subtypes may test negative for HMB45 even when melanoma is present. In such cases, additional IHC markers are required before a final diagnosis can be made. Certain non-melanocytic tumours, including PEComas and tumours associated with tuberous sclerosis complex, can also test positive, which is why clinical context is essential.
How to Maintain Healthy Levels
Because this test is related to melanocytic lesions, the following general skin health practices are worth following:
- Apply broad-spectrum sunscreen and wear protective clothing to reduce UV exposure
- Perform regular self-examinations of your skin, looking for new or changing moles
- Schedule periodic check-ups with a dermatologist, particularly if you have a personal or family history of skin conditions
Lupin Diagnostics IHC Marker - HMB45 Test Price
The IHC Marker - HMB45 test is priced starting at ₹1,920 at Lupin Diagnostics. This test requires a visit to a Lupin Diagnostics centre, as home collection is not available for tissue biopsy samples.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 1920 |
| CHENNAI | 1920 |
| HYDERABAD | 1920 |
| KOLKATA | 1920 |
| NAVI MUMBAI | 1920 |
| PUNE | 1920 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Here is how to schedule your IHC Marker - HMB45 test online booking:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample collection.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The IHC Marker - HMB45 test is an immunohistochemistry test that detects a protein called gp100 in tissue samples. It helps pathologists determine whether a tumour contains melanocytic cells and supports the diagnosis of melanoma and related conditions.
A tissue sample is obtained through a biopsy, which may involve a surgical excision, punch biopsy, or core needle biopsy. Local anaesthesia is used during the procedure. The sample is then fixed in formalin and embedded in paraffin wax for laboratory analysis.
No. While a positive result indicates the presence of melanocytic differentiation, some benign naevi and certain non-melanocytic tumours such as PEComas can also test positive. Your doctor will interpret the result alongside other markers and your clinical history before reaching a diagnosis.
The biopsy procedure may cause mild discomfort, but local anaesthesia is used to minimise pain during sample collection. The IHC test itself is carried out on the tissue in the laboratory and does not involve any further discomfort.
The tissue sample must go through several laboratory steps: fixation, paraffin embedding, thin sectioning, antibody staining, and pathologist review. Each step takes time to ensure accuracy. In some cases, additional markers may also be requested, which can extend the turnaround time.
HMB45 alone may not be sufficient to confirm a diagnosis in all cases. Combining it with other markers, such as S100, significantly increases diagnostic sensitivity. This approach helps detect micrometastases and improves accuracy when the staining pattern with HMB45 alone is unclear.
No. This test requires a tissue sample collected by a trained healthcare professional, followed by specialised laboratory processing. Home collection is not available for this test. You will need to visit a Lupin Diagnostics centre for sample collection.
IHC Marker - HMB45 Test
