Pigmented Lesion Assay (PLA)

DermTech’s Pigmented Lesion Assay (PLA) provides physicians with a non-invasive option to identify clinically atypical pigmented lesions (or moles) at high risk for melanoma. Using an adhesive patch rather than a scalpel, DermTech provides highly accurate, objective information to the physician to improve patient care and comfort through advanced molecular pathology gene expression.

Using the PLA and Non-Invasive Skin Biopsy Kit, a skin sample is collected with adhesive patches, rather than a surgical biopsy, and then sent to DermTech for analysis. The PLA reliably differentiates between gene expression patterns consistent with melanoma and non-melanoma. In two validation studies comparing the 2-gene expression profile to histopathology diagnosis (n=398), the Pigmented Lesion Assay demonstrated 91% accuracy in identifying non-melanoma and melanoma lesions, with a sensitivity of 91% and a specificity of 69%.

The diagnosis of early stage melanoma is inaccurate by visual assessment and histopathologic slide review. The false negative diagnosis for melanoma in-situ/stage 1 a melanoma was found to be 35% in a recent large scale study of pathologists in the US. The PLA has a negative predictive value of 99% and significantly reduces the number needed to biopsy.*

DermTech’s PLA assesses gene expression consistent with melanoma and can aid in the clinician’s biopsy decision. The test is intended for use on pigmented lesions suspicious for melanoma that meet at least one of the ABCDE criteria for which the clinician would like additional information prior to surgical biopsy. PLA uses include:

  • Lesions being followed for change
  • Lesions in cosmetically sensitive areas
  • Lesions on patients with potential risks to surgical biopsy including patients who are anti-coagulated, at risk for infection, and at risk for poor wound healing or elevated abnormal scarring
  • Surgical biopsy refused or contraindicated

The PLA has been validated in samples collected using the Adhesive Skin Collection Kit, distributed by DermTech and used according to the instructions for use.

Instructions for Use

*The test has not been validated for samples collected from mucosal surfaces, the palms of hands, the soles of feet, sites that have been previously biopsied, areas where non-vellus hair cannot be sufficiently trimmed (e.g. scalp), bleeding or ulcerated lesions, pediatric patients, and patients with a Fitzpatrick skin type IV or higher. As with all tests, results should be interpreted by the physician in conjunction with clinical findings and patient risk assessment. The test is not intended for screening or for use on non-pigmented lesions or non-melanoma skin cancer, nor should it be used to confirm a clinical diagnosis of melanoma.