What is Brooke-Spiegler syndrome?
Brooke-Spiegler syndrome (BRSS or BSS) is a rare genetic condition resulting in a range of tumours derived from skin appendages (hair follicle tumours and sweat gland tumours). The syndrome includes the limited variants, familial cylindromatosis and multiple familial trichoepitheliomas (MFT1).
What causes Brooke-Spiegler syndrome?
Brooke-Spiegler syndrome, familial cylindromatosis and multiple familial trichoepitheliomas are due to germline mutations in the cylindromatosis (CYLD) gene on chromosome 16q12. These disorders have an autosomal dominant inheritance, meaning half of an affected individual’s children will also have the condition.
CYLD functions as a tumour suppressor gene and has regulatory roles in development, immunity, and inflammation. To date, a total of 51 germline CYLD mutations have been found. A wide range of ethnic and racial backgrounds have been reported in affected patients and families.
What are the features of Brooke-Spiegler syndrome?
Brooke-Spiegler syndrome results in a predisposition to three types of benign skin appendage tumour.
- Cylindromas — solitary or multiple tumours on the scalp
- Trichoepitheliomas — skin-coloured papules over the central face
- Spiradenomas — painful nodules on head, neck and trunk
Brooke-Spiegler syndrome is also infrequently associated with salivary and parotid gland tumours.
Limited forms of the disease are:
- Familial cylindromatosis – characterised by cylindromas alone; and;
- Multiple familial trichoepitheliomas – characterised by trichoepitheliomas alone.
Affected individuals typically present in late childhood to early adulthood with multiple papules and nodules on the scalp, face and neck. They develop increasing numbers of lesions over time. However, there is a wide variability of presentation within and between families with Brooke-Spiegler syndrome.
Although the tumours are usually considered harmless, there are reports of malignant transformation.
- Spiradenoma may transform into spiradenocarcinoma.
- Cylindroma may transform into cylindrocarcinoma.
- Trichoepithelioma may transform into basal cell carcinoma.
How is the diagnosis made?
Brooke-Spiegler syndrome may be suspected if there is a family history of multiple benign skin tumours.
Cylindromas, trichoepitheliomas and spiradenomas are difficult to distinguish clinically. Therefore skin biopsy is required to confirm the diagnosis.
What treatment is available for Brooke-Spiegler syndrome?
Brooke-Spiegler syndrome is not curable. Possible treatment options for individual tumours include: