How do carcinomas differ from sarcomas

The main difference between carcinomas and sarcomas comes down to tissue. Symptoms and treatments for carcinoma depend on the subtype. Common symptoms of basal cell carcinoma include open sores, red patches, pink growths, and shiny bumps or scars.

Squamous cell carcinomas , on the other hand, tend to crust or bleed, and may appear as scaly patches, open sores or warts. Sarcomas have more than 50 subtypes. The first sign of a sarcoma in an arm, leg or the torso is typically a painless lump or swelling.

In general, sarcomas are treated with surgery , and are harder to treat than carcinomas. New research , though, has found that some sarcomas have a greater immune response than others, and may respond to certain checkpoint inhibitors. Carcinomas are named according to the tissue in which they arise as well as the type of cells. Different subtypes may occur in different regions of the same organ, for example, non-small cell lung cancers may be squamous cell carcinomas of the lung or lung adenocarcinomas.

Similarly, esophageal cancers may arise in squamous cells squamous cell carcinomas or glandular cells adenocarcinomas. Common carcinomas include lung adenocarcinoma, colon adenocarcinoma, squamous cell carcinomas of the head and neck, bladder cancer most often a transitional cell carcinoma , and basal cell carcinomas of the skin.

Unlike carcinomas, there are over 50 different subtypes of sarcomas. Examples of sarcoma based on tissue type include:. The most common sarcomas in childhood are rhabdomyosarcomas.

In adults, the most common sarcomas are soft tissue sarcomas, including undifferentiated pleomorphic sarcoma, liposarcomas, and leiomyosarcomas. The region of the body does not always distinguish sarcomas and carcinomas. Some tumors may have characteristics of both carcinomas and sarcomas and may be referred to as carcinosarcomas or sarcomatoid carcinomas.

Most of the time but not always , the description of a tumor differentiates benign connective tissue tumors from malignant sarcomas. For example, a lipoma is a benign tumor of fat adipose tissue , and a liposarcoma is a cancerous tumor of the tissue. A hemangioma is a benign tumor of blood vessels, whereas a hemangiosarcoma is a malignant tumor. There are exceptions in this classification as well.

For example, a chordoma tumor of the nuchal cord is malignant. A glioma is a cancer not benign tumor of glial cells in the brain. Sometimes, the word malignant is used to distinguish benign and malignant tumors. For example, a meningioma refers to a benign tumor of the meninges membranes lining the brain , whereas a cancerous tumor is referred to as malignant meningioma.

Carcinomas may declare themselves with a number of symptoms often related to the organ in which they arise. For example, lung cancer may present with a cough or shortness of breath, breast cancer may present with a breast lump, and pancreatic cancer may present with jaundice, though not usually until the disease is very advanced.

Sarcomas can likewise present with different symptoms. Sarcomas that arise in the arms and legs often present as a mass that can be painful or painless. When pain is present, it is often worst at night. Sarcomas in bone osteosarcomas may present with bone pain or swelling over or near bones. In some cases, the condition is only diagnosed after a fracture occurs pathologic fracture through an area of bone that has been weakened by the tumor. With Ewing sarcoma , the swelling or lump often feels warm and may be associated with a fever.

Sarcomas of the digestive tract GI stromal tumors may have symptoms similar to colon carcinoma such as blood in the stool, abdominal pain, or weight loss. The major risk factors for carcinomas are fairly well known, and include lifestyle factors such as smoking, obesity, and sedentary behavior , radiation including ultraviolet radiation , genetics, age, viral infections, and environmental exposures among others.

In most cases with sarcomas, identifiable risk factors aren't present, and these tumors have not been found to be associated with smoking, obesity, diet, or lack of exercise. Risk factors for sarcomas may include:. Some sarcomas are associated with certain developmental time periods. For example, osteosarcomas are most common during bone growth between the ages of 10 and With some sarcomas, risk factors have been identified and studied to a greater extent.

For example, angiosarcoma of the breast has been associated with chronic lymphedema , radiation therapy for breast cancer, and a particular type of breast implants that have now been withdrawn from the market. Mesothelioma is strongly associated with asbestos exposure. Rhabdomyosarcomas in children have also been associated with parental use of cocaine and marijuana.

Few risk factors have been identified at this time for Ewing sarcoma, though these cancers appear to be more common among children who have had hernias. The diagnostic process for sarcomas can be similar to carcinomas, and often begins with scans such as a CT scan, MRI, bone scan, or PET scan , or in the case of digestive tract sarcomas, endoscopy. Similarly, a biopsy is needed to determine the type of cancer as well as the tumor grade the aggressiveness of the cancer.

Special stains may likewise be helpful. As with carcinomas, DNA testing such as next-generation sequencing is often helpful, but in the case of some sarcomas, RNA testing may be helpful as well. Unlike carcinomas such as breast cancer, lung cancer, and colon cancer, general screening tests are not currently available for sarcomas.

Precancerous Phase vs. No Precancerous Phase. With carcinomas, tumors can sometimes be detected before they are invasive before they extend through something known as the basement membrane. These precancerous tumors are non-invasive and are referred to as carcinoma in situ or stage 0 cancer. For example, when stage 0 lung cancer is detected it may be treated before it has the opportunity to become invasive and potentially spread.

In contrast, once a sarcoma is detected it is considered invasive. There are also differences in staging methods due to the way in which carcinomas and sarcomas often spread. This section introduces you to the first method: cancer classification based on histological type.

From a histological standpoint there are hundreds of different cancers, which are grouped into six major categories:. Carcinoma refers to a malignant neoplasm of epithelial origin or cancer of the internal or external lining of the body. Carcinomas, malignancies of epithelial tissue , account for 80 to 90 percent of all cancer cases. Epithelial tissue is found throughout the body.

It is present in the skin, as well as the covering and lining of organs and internal passageways, such as the gastrointestinal tract. Carcinomas are divided into two major subtypes: adenocarcinoma , which develops in an organ or gland , and squamous cell carcinoma , which originates in the squamous epithelium. Adenocarcinomas generally occur in mucus membranes and are first seen as a thickened plaque -like white mucosa.

They often spread easily through the soft tissue where they occur.