The term pagetoid (i.e., 'Paget-like') is derived from the extramammary Paget's disease, wherein the large tumour cells are arranged singly or in small clusters within the epidermis and its appendages. These cells are distinguished by a clear halo from the surrounding epithelial cells and a finely granular cytoplasm.
The term 'pagetoid' (i.e., 'Paget-like') is used to describe the characteristic appearance of tumor cells in extramammary Paget's disease, where they are arranged singly or in small clusters within the epidermis and its appendages. These cells have a distinct halo around them compared to surrounding epithelial cells and contain finely granular cytoplasm.