In development
Cutaneous adnexal, or appendageal, tumours comprise a range of benign and malignant tumours that show differentiation towards the adnexal structures found in normal skin. They may display more than one type of differentiation but they are typically classified by the dominant component.
They include the following.
Apocrine and eccrine differentiation
Benign eg poroma, cylindroma
Malignant eg porocarcinoma, digital papillary adenocarcinoma
Follicular differentiation
Benign eg pilomatrixoma
Malignant eg pilomatrical carcinoma, trichilemmal carcinoma
Sebaceous differentiation
Benign eg sebaceous adenoma
Malignant: sebaceous carcinoma
Other special sites
Mammary Paget disease
Extramammary Paget diease
Hidradenoma papilliferum
Pathology departments will adhere to guidelines on specimen handling and reporting as described in the Royal College of Pathology Minimum Data Set (MDS) for adnexal carcinomas.
RSH clinicians are encouraged to use a dedicated form for submission of samples to histopathology.
Tumours should be tested for mismatch repair syndrome with an initial immunohistochemistry screen for mutant MLH1, MSH2, MSH6, PMS2. If any are detected then the patient should be referred to the SW London Regional Genetics Service for full assessment for potential Muir Torre syndrome.