How Melanoma Skin Cancer Is Diagnosed

Among the many types of skin cancer, melanoma is one of the most common. Melanoma can be detected through the ABCDE mnemonic. However, given that many moles look harmless in the early stages, only a skin biopsy can confirm if the mole is indeed a melanoma.

The ABCDE Mnemonic

The ABCDE mnemonic is a method that may help you identify possible skin lesions that are suspicious. The ABCDE stand for the following criteria:

  • A is the asymmetry; moles that have an asymmetric look may be cancerous
  • B stands for border; check the borders of the skin lesion; irregular borders may mean that the mole is made up of cancerous cells
  • C is the color of the mole; irregularities in color may point to melanomas; light brown and colorless moles may be harmless
  • D stands for the diameter of the mole; a mole that has a diameter larger than 6 mm should be tested further
  • E may stand for a number of warning signs: enlargement, if the mole has grown significantly in the past year or even months; elevation, if the mole has increased its volume

This guide may be used with some amendments: the diameter of malignant skin lesions may not always be more than 6 mm. In the early stages, the color of moles may not always be suspicious. Any skin lesions that are itchy or bleed periodically should be checked.

Skin Biopsy

Though the ABCDE mnemonic can help you determine if the skin lesion is suspicious, some types of skin seborrheic keratosis may meet all the criteria, but are still not cancerous. Also, moles that don't have a suspicious look may be melanomas at an incipient stage. A skin biopsy can establish if the skin lesion is a melanoma. There are 2 types of skin testing:

  • The excision biopsy, suitable for smaller moles that are not located on the face or other areas that have a more sensitive skin or are located on uneven surfaces (i.e., eyelids). This type of analysis extracts the entire skin lesion and also a bit of the surrounding skin (1 to 2 mm around each part of the mole)
  • The small punch biopsy is performed by cutting a sample from the mole and analyzing the tissues under the microscope.

Both biopsies should be performed with a local anesthesia, as the procedures may be painful. The tissue testing will be done by a histo-pathologyst, who will determine if the skin lesion is a melanoma.

If the test results show that the skin lesion is a melanoma, the stage of the cancer must be established. Further tests will be needed; these may include x-rays, the lactate dehydrogenase (LDH) test, CT scans, MRI or PET scans. In some cases, a lymph node biopsy will also be performed. If the cancer is not metastasized, the melanoma can be managed and there are high chances of survival.

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