Soft tissue sarcoma in cats and dogs
Encyclopedia
Soft tissue sarcoma
refer to a broad group of tumors that originate from connective tissues. They tend to have similar histologic appearance and biological behavior, and can be either benign
(noncancerous) or malignant
(cancerous). Soft tissue sarcomas can arise in any part of the pet's body but skin
and subcutaneous tumors are the most commonly observed. Soft-tissue sarcomas comprise approximately 15% of all skin
and subcutaneous tumors in dogs and approximately 7% of all skin
and subcutaneous tumors in cats.
The variety of different tumors that fall under the category of soft tissue sarcomas includes fibrosarcoma
, hemangiopericytoma
, liposarcoma
, rhabdomyosarcoma
, leiomyosarcoma
, malignant fibrous histiocytoma
, malignant nerve sheath tumors, myxosarcoma, myxofibrosarcoma, mesenchymoma, and spindle cell tumor.
origin, size, site, histologic grade (level of aggressiveness) and whether it has spread to other organs.
To definitively confirm the diagnosis of a soft-tissue sarcoma, the veterinarian
will have to perform biopsy
for histopathologic evaluation. Additional tests are performed in order to evaluate how advanced the cancer is. These tests generally involve blood and serum biochemical tests, chest X-rays to check for metastasis
to the lungs and imaging studies [eg ultrasound
, computed tomography
(CT) or magnetic resonance imaging
(MRI)] to evaluate the extent of the disease.
, radiation therapy
, and chemotherapy
. Surgery alone or in combination with radiation therapy are used to treat the tumor at its original location, and chemotherapy is usually used to prevent or at least slow down the process of metastasis
in pets diagnosed with tumor subtypes known to be highly aggressive.
Soft tissue sarcoma
A soft-tissue sarcoma is a form of sarcoma that develops in connective tissue, though the term is sometimes applied to elements of the soft tissue that are not currently considered connective tissue.-Risk factors:...
refer to a broad group of tumors that originate from connective tissues. They tend to have similar histologic appearance and biological behavior, and can be either benign
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
(noncancerous) or malignant
Malignant
Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...
(cancerous). Soft tissue sarcomas can arise in any part of the pet's body but skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and subcutaneous tumors are the most commonly observed. Soft-tissue sarcomas comprise approximately 15% of all skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and subcutaneous tumors in dogs and approximately 7% of all skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and subcutaneous tumors in cats.
The variety of different tumors that fall under the category of soft tissue sarcomas includes fibrosarcoma
Fibrosarcoma
Fibrosarcoma is a malignant tumor derived from fibrous connective tissue and characterized by immature proliferating fibroblasts or undifferentiated anaplastic spindle cells.Usually in males ages 30 to 40. Originates in fibrous tissues of the bone. Invades long or flat bones such as femur, tibia,...
, hemangiopericytoma
Hemangiopericytoma
A hemangeopericytoma is a type of soft tissue sarcoma that originates in the pericytes in the walls of capillaries. When inside the nervous system, although not strictly a meningioma tumor, it is a meningeal tumor with an especially aggressive behavior.It was characterized in...
, liposarcoma
Liposarcoma
Liposarcoma is a malignant tumor that arises in fat cells in deep soft tissue, such as that inside the thigh or in the retroperitoneum.They are typically large bulky tumors which tend to have multiple smaller satellites extending beyond the main confines of the tumor.Liposarcomas, like all...
, rhabdomyosarcoma
Rhabdomyosarcoma
A rhabdomyosarcoma is a type of cancer, specifically a sarcoma , in which the cancer cells are thought to arise from skeletal muscle progenitors. It can also be found attached to muscle tissue, wrapped around intestines, or in any anatomic location...
, leiomyosarcoma
Leiomyosarcoma
Leiomyosarcoma , aka LMS, is a malignant cancer of smooth muscle....
, malignant fibrous histiocytoma
Histiocytoma
A histiocytoma is a tumour consisting of histiocytes. Histiocytes are cells that are a part of the mononuclear phagocytic system, a part of the body's immune system that consists of phagocytic cells, which are responsible for engulfing solid particles by the cell membrane to form an internal...
, malignant nerve sheath tumors, myxosarcoma, myxofibrosarcoma, mesenchymoma, and spindle cell tumor.
Signs and symptoms
Soft tissue sarcomas are often detected as a firm mass located on the trunk, limbs, or oral cavity. The symptoms depend on the tumor's location and degree of invasion. For example, tumors in the gastrointestinal tract may cause vomiting, diarrhea, or weight loss. Tumors in the mouth may cause bad breath, difficulty swallowing, or lack of appetite. Tumors arising in the peripheral nerves may cause pain, lameness, or neurological symptoms.Diagnosis
Prior to initiating any type of treatment, it is important to gather as much information as possible regarding the tumor's tissueTissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
origin, size, site, histologic grade (level of aggressiveness) and whether it has spread to other organs.
To definitively confirm the diagnosis of a soft-tissue sarcoma, the veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
will have to perform biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
for histopathologic evaluation. Additional tests are performed in order to evaluate how advanced the cancer is. These tests generally involve blood and serum biochemical tests, chest X-rays to check for metastasis
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
to the lungs and imaging studies [eg ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
, computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
(CT) or magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(MRI)] to evaluate the extent of the disease.
Treatment
There are three main treatment options available to treat soft tissue sarcoma in cats and dogs: surgerySurgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
, radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
, and chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
. Surgery alone or in combination with radiation therapy are used to treat the tumor at its original location, and chemotherapy is usually used to prevent or at least slow down the process of metastasis
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
in pets diagnosed with tumor subtypes known to be highly aggressive.