What is atypical fibroxanthoma?
Atypical fibroxanthoma is a skin tumour that usually occurs on the head and neck of elderly people that have suffered skin damage from overexposure to the sun and/or received therapeutic radiation. The tumour-like growth should be considered a type of skin cancer but it may behave in quite a benign fashion.
A rare type of atypical fibroxanthoma occurs in younger patients on parts of the body that are not normally overexposed to the sun. These tumours are usually found on the trunk and extremities and tend to be larger and slower growing.
What causes atypical fibroxanthoma?
Sun exposure and/or therapeutic radiation that have caused significant skin damage are associated with the development of atypical fibroxanthomas. Both forms of radiation can cause the abnormal growth of tumour cells called spindle cells. These are believed to come from fibrous cells in the dermis (deeper layer of skin) or perhaps sometimes from the epidermal keratinocytes (surface skin cells).
What are the clinical features of atypical fibroxanthoma?
Atypical fibroxanthoma appear on the skin in areas that receive excessive sun exposure, usually around the ears, nose, cheeks, and back of the neck, or in areas where individuals may have previously received radiotherapy treatment. Clinical features of atypical fibroxanthoma are:
- Solitary tumour or multiple tumours may occur
- Red, juicy, dome-shaped nodule that may be ulcerated or crusted
- Tumour starts off as a small nodule that grows quickly over 6 months to a size of about 2-3cm (rarely tumours grow bigger than 3cm)
- The ratio of tumours that occur on the head and neck to tumours that occur in other areas is approximately 4:1
How is atypical fibroxanthoma diagnosed?
Because atypical fibroxanthoma can look like other skin cancers, it is usually diagnosed by a pathologist after its removal or skin biopsy.
What is the treatment of atypical fibroxanthomas?
Atypical fibroxanthoma is treated by surgically removing the tumour. Small lesions may be removed by curettage. A technique called Mohs micrographic surgery is becoming the treatment of choice for large or recurrent lesions as it reliably removes the complete tumour while sparing surrounding normal healthy tissue.
Avoiding excessive sun exposure can prevent atypical fibroxanthoma. Patients should be advised to follow sun protection methods when out in the sun.
- Book: Textbook of Dermatology. Ed Rook A, Wilkinson DS, Ebling FJB, Champion RH, Burton JL. Fourth edition. Blackwell Scientific Publications.
On DermNet NZ:
- Atypical Fibroxanthoma – Medscape Reference
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