carcinoma is a rare but serious type of skin cancer, which is also
called neuroendocrine tumor of the skin. The cancer tends to
grow on the surface of the skin or just below and
in the hair follicles. It is considered as a cutaneous
(skin) neuroendocrine tumor becauseit
originates in the hormone-producing cells that
resemble nerve cells (neuroendocrine cells).
Although Merkel cell carcinoma can appear anywhere, it is most
frequently observed in the head, neck and arms.
The cancer usually develops quickly and often spreads to
other parts of the body to form other cancers (metastasis).
Merkel Cell CarcinomaFrequency
Merkel cell carcinoma cases primarily affects elderly individuals aged 50 years or older. People with light skin are more affected,
with an equal distribution in both sexes.
Its frequency is less than 1/200 000.
Although Merkel cell carcinoma
was described since 1972
by researcher Cyril Toker, studies have been conducted on it until this
day. In 2008, a team of researchers has
identified the existence of viral sequences
within cells of this cancer (Merkel cell polyomavirus). In other subsequent studies, other scientists have confirmed this
Merkel Cell Carcinoma Causes and Risk
The following risk factors may increase the
likelihood that a person will be diagnosed with Merkel cell carcinoma:
cell carcinoma is most commonly diagnosed in light or clear skin people aged
is immunosuppression (suppression of the immune system and its ability to
fight infection) in organ transplant recipients or secondary to HIV infection.
Paul Nghiem of the University of Washington created
an acronym to allow doctors to
remember Merkel cell carcinoma characteristics, and to help
patients recognize risk factors associated
with it, AEIOU:
A because it is an asymptomatic lesion, E because it expands rapidly
for immunocompromised, O for older than 50 years old (individuals aged older than 50 years) and finally U
to UV exposure and light
Merkel cell carcinoma is a dangerous form of
cancer; the prognosis is gloomy and sombermost of the times. It is now
considered more reserved than in the case
of melanoma. However, the survival depends greatly on the stage of the cancer at
There are 4 stages in the evolution
of Merkel cell carcinoma
Stage I: primary lesion
is less than 2 cm,
Stage II: the primary lesion
is greater than 2 cm,
Stage III: the tumor has spread to the nearby
lymph node (non-aggressive metastasis),
Stage IV: the tumor has spread to distant
tissue or organs (aggressive or distant metastasis).
whose lymph nodes are uninfected have a
survival rate at five years more than
80%, but the rate is less than 50% in case the cancer has
spread to lymph node. The technique of
has clouded this prognosis; the
risk of relapse is about 60% in the three
years in case of presence of lymphatic metastases, while it is only
20% in the absence of metastasis.
Although rare, some cases of spontaneous regression due to apoptosis of tumor cells have been
Merkel cell carcinoma
symptoms, treatment survival