Dermatofibrosarcoma protuberans (DFSP) is a rare type of soft tissue sarcoma of the skin that is characterised by the formation of malignant tumours in the connective tissue cells of the dermis (the skin’s middle layer). In this type of soft tissue sarcoma, the tumour most often initiates as a pimple-like small, firm patch of skin, usually measuring 1 to 5 centimetres in diameter, that is primarily reddish, purplish, or flesh-coloured. 

The malignant tumour is a slow-growing one and can become a raised nodule. DFSP Tumours are most commonly detected on the torso and can also be found on the head, neck, arms, or legs. Although, in most cases, DFSP never spreads beyond the skin, timely treatment of removing the tumour, prevents the recurrence and increases the survival rate.

sarcoma

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Types Of Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma Protuberans can be categorised into 4 types:

Bednar Tumours: These are pigmented DFSP tumours that usually comprise cells that have a lot of the skin pigment, melanin. They usually characterise a mix of colours, including red, brown, blue and purple and account for about 5% of all DFSP diagnoses

Giant cell fibroblastoma: This type of DFSP mostly consists of giant cells, known as juvenile DFSP, since it is usually detected in children and teens

Fibrosarcomatous Dermatofibrosarcoma Protuberans (DFSP-FS): This is type of DFSP tumour usually grows fast

Myxoid Dermatofibrosarcoma Protuberans: These are rare types of DFSP tumours that usually comprise an abnormal type of connective tissue called the myxoid stroma

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Causes

Just like any other form of soft tissue sarcoma, the absolute cause of DFSP is yet unknown but some clinical trials and scientific data indicate that this condition might occur due to a rearrangement or translocation of genetic material between chromosome 17 and chromosome 22. This rearrangement. This somatic mutation triggers the healthy cells to proliferate and differentiate abnormally, leading to a huge mass of irregular cells which combine to form tumours as seen in dermatofibrosarcoma protuberans. 

Risk Factors

Certain causative factors that aggravate the chances of getting dermatofibrosarcoma protuberans include:

Age: Although DFSp is usually noticed in adults between 20 - 50, even children and teens have some form of DFSP

Race: The risk of DFSP is more in people of Black origin than in other ethnicities

Skin Conditions: People having any skin injury, scars, burns or tattoos have a higher incidence of getting DFSP

Medical Treatments: People who underwent radiation therapy or any surgical incision have an aggravated risk of this type of cancer

Symptoms

The initial symptoms of DFSP are hard to notice. They usually appear as a small patch of bruised skin, a flat and painless spot which is rough and discoloured. These nodules chiefly appear on the chest, back, shoulders, arms, legs, scalp, abdomen, buttocks and inside of your mouth.

These nodules become more prominent as the tumour grows in size. The growing tumour then pushes into the epidermis or the top layer of skin and appears on the skin (“protuberans”).

Characteristics of the nodules:

  • Easy to bleed or crack open 
  • Reddish-brown to blue,  violet, or red
  • Tender to the touch
  • Firmly attached to the epidermal layer of the skin
  • Getting bigger and stretching the surface of the skin
  • Hard or rubbery surface of the nodule

Diagnosis And Treatment

In case you notice any of the above-said indications, consult an oncologist at the earliest, since the tumours might have already grown bigger. The doctor acknowledges the patient's medical history, and history of carcinogenic exposures and conducts the following diagnostics:

Treatment

The available treatment plan for Dermatofibrosarcoma Protuberans mainly depends on the stage, size, and location of the tumour and the general physical condition of the patient. The treatment mainly includes the following steps:

  • Surgery to remove the tumour
  • Moh’s surgery
  • Chemotherapy
  • Radiation therapy
  • Targeted therapy
  • Clinical trials
  • Palliative care