Dermatofibrosarcoma protuberans (DFSP) is a rare type of sarcomacancer arising from bones and/or soft tissue that starts in the skin. More specifically, it develops from connective tissuea group of cells that work together to perform a function cellsthe basic structural and functional unit of all living things in the middle layer of the skin, called the dermis.
The skin is the largest organ in our bodies that protects us from injury, loss of bodily fluids, and helps regulate body temperature. There are three layers of the skin: epidermis (top layer), dermis (middle layer), and hypodermis (bottom layer). The epidermis is the water-resistant outer layer of the skin that acts as the body’s first line of defence. It contains squamous cells (upper layer of epidermis) and melanocytes. The dermis contains the skin’s connective tissues, as well as hair follicles, sweat glands, bloodthe red bodily fluid that transports oxygen and other nutrients around the body vessels, lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid, and nerves. The hypodermis, also known as subcutaneousunder the skin tissue layer, stores fat (adipose cells), and contains connective tissue, blood vessels, and nerve cells.
As connective tissue is found everywhere in the body, DSFP can develop just about anywhere. However, it is most commonly found in the torso, shoulder, chest, limbs, head and/or neck.
DFSP is slightly more common in males, and tends to develop in people between 20-59 years of age. However, anyone can develop this disease.
Types of DFSP
There are four rare variations of DFSP, which are categorised by the type of cells they develop from.
Pigmented DFSP/Bednar Tumours
Pigmented DFSP, also known as Bednar tumours, is a rare subtype of DFSP that is most commonly found in the shoulder region. It is categorised by the presence of melanin (the substance responsible for pigmentation of the skin, hair, and eyes) within the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs cells, causing tumoura tissue mass that forms from groups of unhealthy cells colour to vary. These tumours can be locally aggressive, however they rarely metastasise and often carry a good prognosisto predict how a disease/condition may progress and what the outcome might be.
Myxoid DFSP
Myxoid DFSP is a rare subtype of DFSP that is most commonly found in the arms, legs, and trunk. It is categorised by the presence of myxoid stroma, an unusually blue or purple type of connective tissue), within the cancer cells. These tumours can be locally aggressive, but rarely metastasise and can have a good prognosis.
Giant Cell Fibrosarcoma/Juvenile DFSP
Giant cell fibrosarcoma, also known as juvenile DFSP, is a rare subtype of the disease that is generally found in children and adolescents. It is characterised by abnormally large cancerous cells, and can be aggressive. These tumours rarely metastasise, and can have a good prognosis.
Fibrosarcomatous DFSP
Fibrosarcomatous DFSP, also known as DFSP with fibrosarcomatous differentiation, is a rare subtype of this disease that is most commonly found in the arms, legs, trunk, head, and neck. Its cellular appearance is very similar to ordinary DFSP, but is generally more aggressive. These tumours are more likely to metastasise, and may not have as good as a prognosis as other subtypes of DFSP.
Treatment
When cancers are detected, they are staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you. However, because of how rare DFSPs are, there is currently no standard staging and grading system for this disease. Instead of staging and grading, your doctor will recommend a treatment plan based on the following factors:
- Cancer location.
- Whether or not the cancer has metastasised.
- Your age.
- General health.
- Your treatment preferences.
Your doctor may also recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment options for DFSP may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Surgical excisionto surgically remove/cut out of the tumour.
- Mohs micrographic surgeryspecialised surgery that removes thin layers of cancer in stages until completely removed.
- Reconstructive surgerysurgery to restore appearance and/or function to an area of the body – such as flap surgerya type of plastic surgery where healthy tissue is moved from one area of the body to another to reconstruct an area that was damaged or removed.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Targeted therapymedication that targets specific molecular features of cancer cells, potentially including tyrosine kinase inhibitors such as Imatinib.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare DFSP is, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease. However, studies have shown a potential link between previous skin injury and the development of DFSP.
Symptoms
Early symptoms of DFSP may include:
- Painless plaque (thickened area of skin) or nodule on skin.
- Rubbery or firm nodule on skin.
- Red-brown, pink, or blueish discolouration of nodule.
- Soft, depressed (or indented) area of skin (rare).
- Ulceration of nodule over time.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a DFSP, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, such as a MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
