Tumour consists of sharply demarcated lobules located
in the dermis without connection to the epidermis ;
PAS positive basement membrane-like material may be present around the
Two cell types are
present ; Small cells with dark nuclei are present at the periphery
and the large paler cells are at the centre ;
Cells are arranged
around small lumina ;
Lumina contains small amounts of granular eosinophilic material that is PAS- positive and diastase resistant ;
lymphocytes are present throughout the tumour lobules.
Tumour may show
prominent degenerative changes, fibrosis and cyst formation ;
Ancient changes (dilated
vessels rimmed by sclerosis) ;
are partially or totally necrotic ;
Strands of cells are cytokeratin positive and lumina are CEA positive.