Fig. 3

Histological examination. a, b Microscopic examinations showed alveolar solid and cribriform patterns in the resected specimen (hematoxylin and eosin staining ×40, 200). c PAS and d Alcian blue staining of intraluminal substance in the tubular pattern region (×100). e–g Immunohistochemical staining with e cytokeratin, f vimentin, and g S-100 protein (×100)