top of page

ACRAL PIGMENTED LESIONS

  • A diagnostic flow chart for acral pigmented lesions can be found here.  The paper that contains that algorithm is a good summary of diagnosis and management of acral pigmented lesions. 37556446

  • The BRAAFF checklist is another approach to the diagnosis of acral melanoma. 26211689

  • Nail bed pigmented lesions in children are VERY uncommonly malignant.  Congenital nevi result in breaking of a lot of the typical diagnostic guidelines. (Dermoscopy Excellence) 

FACIAL PIGMENTED LESIONS

  • The differential of facial pigmented lesions on the face primarily includes solar lentigo and seborrheic keratosis. 

  • The reticular network on the face is NOT suggestive of a melanocytic lesion.  This is in strict contrast to the trunk and extremities.  A reticular pattern on the face is usually indicative of a solar lentigo or reticulated seborrheic keratosis.  

  • One useful diagnostic algorithm is the inverse approach which excludes melanoma by focusing on 6 non-melanoma features to make the diagnosis of an solar lentigo or seborrheic keratosis in lieu of a melanoma. 32592885

​​

Inverse Approach - 6 non-melanoma features (28761960)

Actinic Keratosis

  1. Scales (pigmented or non-pigmented)

  2. White and wide follicles or rosettes

  3. Erythema or reticular vessels

Solar Lentigo/Seborrheic Keratosis

  1. Lines - reticular or parallel (fingerprint-like patterns)

  2. Sharp demarcation

  3. Classic SK criteria

​

  • Examples of these criteria can be found here.

​​

Pathology 

  • Providing clinical information to the pathologist may improve inter-rater reliability and prevent missing evolving melanomas.  It results in upgrading, and the impact of this as a positive or negative is unclear. 39476175

​​

Inverse Approach - 6 non-melanoma features (28761960)

Actinic Keratosis

  1. Scales (pigmented or non-pigmented)

  2. White and wide follicles or rosettes

  3. Erythema or reticular vessels

Solar Lentigo/Seborrheic Keratosis

  1. Lines - reticular or parallel (fingerprint-like patterns)

  2. Sharp demarcation

  3. Classic SK criteria

​

  • Examples of these criteria can be found here.

​​

GENETIC TESTS

  • DermTech is a genetic test that measures genomic atypic by measuring RNA LINC00518 and PRAME, and anti-DNA TERT.  The sample is obtained by stripping superficial layers of skin with tape.   

  • In a review of 44 cases for which a biopsy was performed after a DermTech test was performed (because of a positive test result, or clinical concern), it correctly identified 9 of 10 melanomas (5 in situ, 4 invasive) and missed 1 LM.  Of 14 non-nevi, it incorrectly gave positive results to 11.  2 out of 2 severely dysplastic nevi were given positive results.  15 out 17 mild, moderate, or nevi otherwise considered to be of low malignant potential were classified as positive.  Because many negative test results did not receive biopsy, sensitivity and specificity cannot be calculated, but this does highlight the relatively inaccurate nature of the test, particularly with respect to false positive results (~68% of results in this cohort were false positives).  37549792

External Medicine

 Conceived 2016

DISCLAIMER: This website is a collection of primary literature and the opinions of the website creators on that literature.  It is not intended to be used for the practice of medicine or the delivery of medical care in the absence of other appropriate credentials (like a medical degree).  Discuss any information with your doctor before pursuing treatments mentioned on this site.  

bottom of page