Anorectal mucosal melanoma: Diagnosis and staging
It is important that you see your GP if you have symptoms or any ongoing unexplained symptoms that are worrying you. Your GP will examine you which will usually involve feeling your tummy (abdomen) and they may also look for any abnormalities (such as lumps of swellings) in your back passage (rectum). This procedure is called a rectal examination which may be uncomfortable but shouldn’t be painful.
Your GP may also feel your groin area for any swollen lymph nodes.
If your GP has any concerns or if they are not sure what the problem is, they will refer you to a hospital specialist who will examine you again and will arrange for you to have a biopsy. This is a small sample of the tissue that will be removed under local anaesthetic to look for cancer cells. It is then analysed by a pathologist (a specialised doctor who diagnoses diseases from tissue and cells in the body) to determine whether it is a melanoma or not. It typically takes a few weeks to receive the results of your biopsy and this can be a very anxious time. You may have other tests to help diagnose anorectal melanoma and these tests can also be used to check whether your anorectal melanoma has spread to other parts of your body.
Staging for anorectal mucosal melanoma
After a diagnosis of anorectal mucosal melanoma, your medical team will work out the ‘stage’. The stage is a way of describing the key features of your melanoma and is helpful in guiding the best treatment and follow-up for you. Your stage provides an indication of how advanced your melanoma is. Generally, the higher the stage, the more advanced it is.
Staging for anorectal melanoma is different from other mucosal melanomas and is often staged as follows:
Stage 1 = the melanoma is ‘localised’ which means it is only in the anus and rectum and it has not spread anywhere else
Stage 2 = the melanoma has spread to nearby lymph nodes
Stage 3 = the melanoma has spread to other parts of the body (metastasised) – the most common location for spread is the liver for anorectal melanoma