Dermatofibroma
Dermatofibroma, also called a cutaneous fibrous histiocytoma, is a common benign fibrous growth of the skin. They are composed of a mixture of fibroblastic and histiocytic cells, collagen, and blood vessels. They are firm and often feel like a stone under the skin, most common on the arms, lower legs, and upper back. Dermatofibromas are seen in adults and are rare in children.
Dermatofibroma is usually solitary. However, multiple dermatofibromas are can develop in people with weakened immune system. Also, they tend to grow slowly. They occur more frequently in women than in men, however, some histologic variants are more common in males.
- May be caused by an adverse reaction to an injury to the skin such as a bug bite, splinter or other puncture wound.
- Age may be another risk.
- People with suppressed immune system such as systemic lupus.
- May be caused by an adverse reaction to an injury to the skin such as a bug bite, splinter or other puncture wound.
- Age may be another risk.
- People with suppressed immune system such as systemic lupus.
- Appears as a round bump that is mostly under the skin, 0.5 – 1.5 cm in diameter, but most lesions are 7 – 10 mm in diameter, and usually remains stable.
- Pink to light brown in white skin, dark brown to black in dark skin; some appear paler in the centre with a rough surface.
- Lesion feels hard, like a stone under the skin.
- Mostly found on the legs, sometimes on the arms and trunk.
- Usually painless, but occasionally itchy and painful.
- When pinched, dermatofibroma will not push towards the surface of the skin, but will dimple inward- “dimple sign”.
- Lesion may be traumatised such as by a razor.
- Usually solitary, however, occasionally may develop multiple lesions in setting of immunosuppression.
- Appears as a round bump that is mostly under the skin, 0.5 – 1.5 cm in diameter, but most lesions are 7 – 10 mm in diameter, and usually remains stable.
- Pink to light brown in white skin, dark brown to black in dark skin; some appear paler in the centre with a rough surface.
- Lesion feels hard, like a stone under the skin.
- Mostly found on the legs, sometimes on the arms and trunk.
- Usually painless, but occasionally itchy and painful.
- When pinched, dermatofibroma will not push towards the surface of the skin, but will dimple inward- “dimple sign”.
- Lesion may be traumatised such as by a razor.
- Usually solitary, however, occasionally may develop multiple lesions in setting of immunosuppression.
- Doctor performs visual inspection and pinch the lesion to check for dimpling.
- May use a dermatoscope to take a magnified view at the surface of the lesion, dermatofibromas usually have a central white area in the middle, surrounded by the pigmentation viewed with a dermatoscope.
- If the lesion has an abnormal shape, bleeding or has a sore on top of it, doctor may do a biopsy, involves removing a small sample of lesion to assess under the microscope at a lab.
- Doctor performs visual inspection and pinch the lesion to check for dimpling.
- May use a dermatoscope to take a magnified view at the surface of the lesion, dermatofibromas usually have a central white area in the middle, surrounded by the pigmentation viewed with a dermatoscope.
- If the lesion has an abnormal shape, bleeding or has a sore on top of it, doctor may do a biopsy, involves removing a small sample of lesion to assess under the microscope at a lab.
- Usually, dermatofibroma is harmless and asymptomatic so can be left alone.
- If the lesions are in an inconvenient spot, can seek options to remove them, however recurrence is common as the lesion often extends beyond the clinical margin.
- Some nodules can be shaved superficially, flattened down to the level of the skin but may grow back with time.
- Cryotherapy, shave biopsy and laser treatments are rarely completely successful.
- Removing the dermatofibroma completely may leave noticeable scar tissue.
- Usually, dermatofibroma is harmless and asymptomatic so can be left alone.
- If the lesions are in an inconvenient spot, can seek options to remove them, however recurrence is common as the lesion often extends beyond the clinical margin.
- Some nodules can be shaved superficially, flattened down to the level of the skin but may grow back with time.
- Cryotherapy, shave biopsy and laser treatments are rarely completely successful.
- Removing the dermatofibroma completely may leave noticeable scar tissue.
- Dermatofibromas remains for life and do not disappear on their own unless they are removed.
- If the dermatofibroma experiences a significant change in color, size, border or becomes symptomatic, patient should follow up with the doctor.
- Dermatofibromas remains for life and do not disappear on their own unless they are removed.
- If the dermatofibroma experiences a significant change in color, size, border or becomes symptomatic, patient should follow up with the doctor.
