Carcinomas are cancers that develop in epithelial cells, which cover the internal organs and outer surfaces of your body. Sarcomas are cancers that develop in mesenchymal cells, which make up both your bones and soft tissues, such as muscles, tendons, and blood vessels.
The main difference between carcinomas and sarcomas is where they originate.

Carcinomas: Carcinomas, which originate in epithelial cells, tend to affect your skin or mucous membranes. The five most common types of carcinoma include:
Adenocarcinoma. This type of carcinoma affects organs that produce fluids or mucous, such as the breasts or prostate.
Basal cell carcinoma. This type affects the cells that form the foundation of your outer-most layer of skin. This is the most common type of skin cancer.
Squamous cell carcinoma. This type affects the cells above the basal cells in your skin and is the second most common type of skin cancer.
Transitional cell carcinoma. This type affects transitional cells in your urinary tract, including your bladder, kidneys, and ureter.

Sarcomas: Sarcomas are tumors that develop from soft tissue cells called mesenchymal cells. Mesenchymal cells help form and support many vital organs and tissues, such as:

bones
blood vessels
cartilage
nerves
muscles
fat
joints
tendons
ligaments
While rare, there are over 75 types of sarcomas. They can occur anywhere, but are most common in the abdomen, arms, or legs.

The most common types of sarcoma include:

Undifferentiated pleomorphic sarcoma. This type of sarcoma involves soft tissue and bone cells at the same time.
Leiomyosarcoma. This type of sarcoma involves smooth muscle cells that line your blood vessels, gastrointestinal tract, and uterus.
Osteosarcoma. This type of sarcoma involves bone cells.
Liposarcoma. This type of sarcoma involves fat cells.

Carcinomas and sarcomas also differ in how common they are. While carcinomas are more common, sarcomas are rarer.

Carcinomas
About 90 percentTrusted Source of all cancers cases involve a type of carcinoma.

Carcinomas affect people of all ages, genders, and ethnicities. There are different risk factors for different carcinomas. Some of these risk factors include:

smoking
excessive alcohol consumption
long-term exposure to ultraviolet light from the sun or tanning beds
long-term exposure to heavily polluted air
obesity
inactivity or lack of physical fitness
being fair skinned
Sarcomas
According to Cancer Research UK, sarcomas account for less than 1 percent of cancers diagnosed each year.

Like carcinomas, sarcomas can affect anyone. However, certain medical conditions, environmental influences, and lifestyle habits can increase your risk of developing a type of sarcoma.

Medical risk factors for sarcomas include:

tubular sclerosis (Bourneville disease)
retinoblastoma
neurofibromatosis type 1 (Von Recklinghausen’s disease)
familial adenomatous polyposis (Gardner’s syndrome)
nevoid basal cell carcinoma syndrome (Gorlin syndrome)
Werner syndrome
Li-Fraumeni syndrome
Environmental and lifestyle risk factors for sarcoma include:

exposure to harmful or toxic chemicals, especially arsenic, thorium dioxide, and vinyl chloride
exposure to radiation during cancer therapy
exposure to repeated radiation from continual or frequent diagnostic imaging scans, like X-rays
In addition, some types of sarcomas are more common in certain age groups.

Types of sarcomas that are more common in infants, children, and young adults include:

rhabdomyosarcoma
osteosarcoma
alveolar soft-part sarcoma
desmoplastic small round cell tumor
epithelioid sarcoma
synovial sarcoma
infantile fibrosarcoma
Types of sarcomas that are more common in adults include:

adult fibrosarcoma
fibromyxoid sarcoma, low-grade
liposarcomas
myxofibrosarcomas, low-grade