Microscopic review of the 24 PA analyzed cases showed they were composed by different structures in variable quantities: sheets and groups of epithelial polygonal cells, ductiform structures, squamous metaplastic cells, keratin pearls; MMyECs were fusiform, hyaline and clear, combined with variable quantities of hyaline, mucoid, myxoid and chondroid areas accompanied by eosinophilic coagula within the ducts ( Figure 1 ).
Source: wiktionary