Name of the Procedure:

Oncology (cutaneous melanoma), mRNA Gene Expression Profiling by RT-PCR of 23 Genes (14 Content and 9 Housekeeping), Utilizing Formalin-Fixed Paraffin-Embedded Tissue, Algorithm Reported as a Categorical Result (e.g., Benign, Indeterminate, Malignant)

Summary

This test examines the genetic expression of a sample taken from a cutaneous melanoma (a type of skin cancer) to determine the cancer's status as benign, indeterminate, or malignant. The procedure uses a technique called reverse transcription-polymerase chain reaction (RT-PCR) to assess the activity of 23 specific genes within a preserved tissue sample.

Purpose

The test is used to diagnose and classify cutaneous melanoma, a type of skin cancer, by analyzing gene expression. The primary goal is to determine the tumor’s nature—whether it is benign, malignant, or indeterminate—helping guide further treatment and management.

Indications

• Patients diagnosed with or suspected of having cutaneous melanoma.
• Individuals with atypical moles or lesions where the nature of the tissue needs further investigation.
• Cases where initial biopsy results are inconclusive.

Preparation

• No specific patient preparation is required as the test uses previously collected tissue samples.
• The tissue sample must be preserved in formalin and embedded in paraffin.

Procedure Description

1. A tissue sample from a suspected melanoma is collected and preserved in formalin, then embedded in paraffin.
2. The tissue’s RNA is extracted and converted into DNA using reverse transcription.
3. The converted DNA is then amplified using polymerase chain reaction (PCR) to measure the expression of 23 genes.
   • 14 content genes related to melanoma.
   • 9 housekeeping genes used as controls.
4. Results are processed through an algorithm that categorizes the tumor as benign, indeterminate, or malignant.

Duration

The analysis typically takes several days to a few weeks, depending on the laboratory’s workload and processing times.

Setting

The test is conducted in a specialized pathology laboratory.

Personnel

• Pathologists
• Laboratory technicians specialized in molecular diagnostics
• Oncology specialists

Risks and Complications

• No direct risks to the patient as existing tissue samples are used.
• Rare cases of incorrect categorization due to sample contamination or technical errors.

Benefits

• Accurate classification of melanoma status.
• Helps in making informed decisions about further treatment and management.
• Improved prognosis by facilitating early and appropriate intervention.

Recovery

• No post-procedure care is required as this is a laboratory test.
• Patients may need to discuss results and further treatment options with their oncologist.

Alternatives

• Traditional histopathological examination.
• Genetic sequencing or other molecular profiling techniques.
• Direct observation and regular dermatological assessments (in cases of indeterminate lesions).

Patient Experience

• No immediate physical experience as the test is performed on previously collected tissue.
• Anxiety may be associated with awaiting results.
• Pain management and comfort measures are generally unnecessary.