Dr. Susan's Pei's Headshot

How skin cancer is diagnosed

In determining whether a suspicious lesion is cancer, doctors will take a biopsy — removing all or part of the abnormal area — and send it to our dermatopathologists for examination and testing. For suspected skin cancers, your physician will likely do one of the following procedures:

  • Shave biopsy – abnormal growth is shaved off with a sharp blade
  • Punch biopsy – a sharp, hollow device removes a small but deep sample of tissue
  • Incisional biopsy – only a piece of the lesion is removed
  • Excisional biopsy – the entire mole or growth and some tissue around it is removed with a scalpel

Why your pathologist matters

Cancer patients see many doctors during the course of their treatment, but rarely do they meet the specialist who plays the most critical role in their outcome: the pathologist who diagnoses their cancer by analyzing samples of blood, tissue and body fluid. Precise diagnosis is what drives all subsequent decisions about treatment options and other patient choices.

The dermatopathologists at Roswell Park have received extensive training in the study of skin cancers. They directly review all of the pathology slides from your biopsy (whether it was performed at Roswell Park or by an outside physician) and render an expert opinion on the key characteristics that will define your skin cancer treatment.

The Roswell Park difference: Roswell Park is the only provider in the Western New York region that offers a full molecular pathology service, fast-tracking diagnosis and avoiding delay in commencing treatment. This includes the following key pathology studies:

  • Immunohistochemistry study – By adding an antibody, dye, or radioisotope to the sample of cancer cells, the pathologist looks for certain antigens or proteins, that help identify one skin cancer type from another.
  • Light and electron microscopy – Cells are viewed using a high-powered microscope to look for changes in the cancer cells
  • Cytogenic analysis – Cells are viewed to look at the actual chromosomes of the cancer cell
  • FISH (fluorescence in situ hybridization) – A process that allows the pathologist to look at the actual genes and chromosomes of the cell.
  • Flow cytometry – A test which measures the number of cells in a sample and can determine the percentage of cells that are live, or have a certain characteristic, size, shape or tumor marker.
  • DNA Sequencing  Process that determines the order of components in a single DNA molecule.

Has your skin cancer spread?

Basal cell carcinoma, which begins in the lower part of the epidermis, rarely spreads to other places in the body. However, certain squamous cell carcinomas may spread to lymph nodes and other organs. If your skin cancer is at high risk of spreading, your doctor may recommend additional tests to learn whether the cancer has grown deeper in the skin or spread to lymph nodes or other parts of the body. Whether or not cancer is found in these areas helps determine the stage of your cancer.