Neuroendocrine Carcinoma

Neuroendocrine carcinoma (Merkel cell) – Is a rare and aggressive cancer that begins in the hormone-producing cells beneath the skin, in the hair follicles and also is found on the head and neck. This cancer often presents in individuals older than 50 years old, who has a weak immune system. Neuroendocrine carcinoma is also called, Merkel Cell or trabular cancer.

Key Points

  • Merkel cell carcinoma is a rare disease that occurs when malignant (cancer) cells form in the skin.
  • Risk factors for Merkel cell carcinoma include having a weak immune system and unprotected sun exposure.
  • Merkel cell carcinoma usually presents as a single painless lump on the head or neck area, or other sun exposed parts of the skin.

Overview

Merkel cells are a type of cell that is found close to the nerve endings that receive sensation to touch in the hair follicles on the top layer of the skin. Merkel cell carcinoma is a rare type of skin cancer, that frequently starts on sun exposed areas of the head, neck, and extremities. Merkel cell carcinoma is caused by the cells reproduce more than is needed for a healthy body, and metastasizes, or spreads, rapidly at an early stage. This cancer will quickly spread to lymph nodes, and from there travel to the lungs, brain, bones or other organs.

Risk Factors

  • Being exposed to a lot of natural sunlight.
  • Being exposed to artificial sunlight, such as from tanning beds or psoralen and ultraviolet A (PUVA) therapy for psoriasis.
  • Having an immune system weakened by disease, such as chronic lymphocytic leukemia or HIV infection.
  • Taking drugs that make the immune system less active, such as after an organ transplant.
  • Having a history of other types of cancer.
  • Being older than 50 years, male, or white.
(information provided by the National Cancer Institute.)

Signs and Symptoms

Merkel cell carcinoma usually appears on sun-exposed skin as a single lump that is:
  • Fast-growing.
  • Painless.
  • Firm and dome-shaped or raised.
  • Red or violet in color.

Diagnosis

Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken. Full-body skin exam: A doctor or nurse checks the skin for bumps or spots that look abnormal in color, size, shape, or texture. The size, shape, and texture of the lymph nodes will also be checked. Skin biopsy : The removal of skin cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. Certain factors affect prognosis (chance of recovery) and treatment options.

High Risk Features

  • The stage of the cancer (the size of the tumor and whether it has spread to the lymph nodes or other parts of the body).
  • Where the cancer is in the body.
  • Whether the cancer has just been diagnosed or has recurred (come back).
  • The patient’s age and general health.
Prognosis also depends on how deeply the tumor has grown into the skin.

Staging

After Merkel cell carcinoma has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body. The process used to find out if cancer has spread to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following stages are used for Merkel cell carcinoma: Tumor size compared to everyday objects; shows various measurements of a tumor compared to a pea, peanut, walnut, and lime Pea, peanut, walnut, and lime show tumor sizes.

Stage 0 (carcinoma in situ)

In stage 0, the tumor is a group of abnormal cells that remain in the place where they first formed and have not spread. These abnormal cells may become cancer and spread to lymph nodes or distant parts of the body.

Stage IA

In stage IA, the tumor is 2 centimeters or smaller at its widest point and no cancer is found when the lymph nodes are checked under a microscope.

Stage IB

In stage IB, the tumor is 2 centimeters or smaller at its widest point and no swollen lymph nodes are found by a physical exam or imaging tests.

Stage IIA

In stage IIA, the tumor is larger than 2 centimeters and no cancer is found when the lymph nodes are checked under a microscope.

Stage IIB

In stage IIB, the tumor is larger than 2 centimeters and no swollen lymph nodes are found by a physical exam or imaging tests.

Stage IIC

In stage IIC, the tumor may be any size and has spread to nearby bone, muscle, connective tissue, or cartilage. It has not spread to lymph nodes or distant parts of the body.

Stage IIIA

In stage IIIA, the tumor may be any size and may have spread to nearby bone, muscle, connective tissue, or cartilage. Cancer is found in the lymph nodes when they are checked under a microscope.

Stage IIIB

In stage IIIB, the tumor may be any size and may have spread to nearby bone, muscle, connective tissue, or cartilage. Cancer has spread to the lymph nodes near the tumor and is found by a physical exam or imaging test. The lymph nodes are removed and cancer is found in the lymph nodes when they are checked under a microscope. There may also be a second tumor, which is either:
  • Between the primary tumor and nearby lymph nodes
  • Farther away from the center of the body than the primary tumor is

Stage IV

In stage IV, the tumor may be any size and has spread to distant parts of the body, such as the liver, lung, bone, or brain.

Treatments

Once Merkel cell carcinoma (MCC) has been diagnosed and staged, your cancer care team will discuss your treatment options with you. Depending on your situation, you may have different types of doctors on your treatment team. These doctors may include:
  • A dermatologist: a doctor who treats diseases of the skin
  • A surgical oncologist (or oncologic surgeon): a doctor who uses surgery to treat cancer
  • A medical oncologist: a doctor who treats cancer with medicines such as chemotherapy
  • A radiation oncologist: a doctor who treats cancer with radiation therapy