Hello and welcome to HCM
Some cancer are very aggressive and spread to distant sites. cutaneous metastasis
is commonly seen in many cancers like carcinoma of gall bladder
, carcinoma of lung, carcinoma of breast etc.
In case of your patient if it is proven/ confirmed that the tumor
cells from carcinoma prostate
has spread to the forehead then swelling of this type is described as 'Cutaneous metastasis' or 'tumor nodule'.
Thanks for posting your query.
Dr Shailja P Wahal