Diagnosis
Contact a doctor immediately if you notice any new spot or lump on your skin that is changing in size or appearance, growing rapidly, or bleeding. Early diagnosis is very important for Merkel cell carcinoma, as this disease is highly aggressive. The doctor will thoroughly examine your skin and ask about your general health, lifestyle, and family history. You may need to see a dermatologist (skin doctor), who will use a dermatoscope, a magnifying lens with a light, to look at the skin more closely. If the doctor thinks a spot may be Merkel cell carcinoma, he will perform a biopsy to be certain. Here are some procedures the doctor may recommend to diagnose and stage Merkel cell carcinoma:
Skin Biopsy
A biopsy is the only way to be certain a spot on your skin is cancer. The doctor will take a tissue sample from a suspicious area of your skin and send it to a lab to be examined under a microscope. There are a few different types of skin biopsies:
Click Image to Enlarge.
Punch Biopsy
A surgeon uses a special instrument to remove a cylinder of tissue from deeper layers of skin. A punch biopsy is good for determining the depth of the lesion. The punch biopsy is optimal because it can determine depth more accurately.
Click Image to Enlarge.
Shave Biopsy
A surgeon uses a razor blade to shave off the outer layers of the skin to be examined under a microscope. One problem with the shave biopsy is that it may miss the true extent of the depth of the lesion.
Click Image to Enlarge.
Incisional Biopsy
A surgeon uses a scalpel to make an incision and remove only a part of the suspected tumor for examination. This type of biopsy is not optimal unless absolutely necessary (for example, with very large tumors that cannot undergo punch biopsy).
Click Image to Enlarge.
Excisional Biopsy
A surgeon uses a scalpel to remove the entire lump or spot and a margin of surrounding tissue for examination. Excisional biopsies are also generally not optimal because without a prior diagnosis, adequate excision margin planning is not possible.
Additional Tests
Once the diagnosis is made, the doctor will perform additional tests to determine the stage of the disease. These tests may include:
Physical Examination
The physician will check to see if there are any other lesions on the skin, especially in the tract between the primary skin tumor and the lymph node areas close by. The exam will also check to see if any of the lymph nodes feel abnormally large or hard
Click Image to Enlarge.
Sentinel Lymph Node Biopsy
This specialized lymph node biopsy is performed to find out whether the cancer has spread to the lymph nodes. Surgeons are able to pinpoint which lymph nodes the cancer is most likely to spread to first (called sentinel lymph nodes). The surgeon then removes these sentinel nodes and sends them to a laboratory for further testing. A pathologist then examines the nodes under a microscope to determine if they contain cancer cells. This procedure is especially important for Merkel cell carcinoma, even if there is no obvious lymph node involvement, due to the aggressive nature of the disease.
Click Image to Enlarge.
Computed tomography (CT) scan
A computed tomography (CT) scan uses X-rays to produce an image of your body. A special dye may be injected into your veins and you may be asked to drink a special fluid in order to make the internal organs or vessels stand out. A CT scan reveals the presence of tumors and whether or not the cancer has spread to other parts of the body.
Click Image to Enlarge.
Positron emission tomography (PET) scan
For a PET scan, the doctor injects a radioactive substance (actually a form of glucose, a common sugar) into the patient's bloodstream. This substance collects preferentially in malignant (cancerous) cells in the patient's body. The doctor then uses a PET scanner to detect these areas of radioactivity and to determine the exact location of cancer in the patient's body. PET scans may also be combined with CT scans (PET/CT scan).
Chest X-ray
X-rays use electromagnetic radiation to produce images of the inside of your body. Your doctor may order a chest X-ray to see whether the cancer has spread to other parts of the body and to rule out small-cell lung cancer.
