Histopathology finding of tumor. (A) The hyperplastic columnar epithelium characterized by basally located nuclei forming small papillary projections with crowding of slightly enlarged nuclei in the stoma tissue sample. Crypt-like invaginations can be found focally (H&E, 100×). (B) Foci of squamous metaplasia and the glandular element are present in the neoplasm. Squamous cells show slight or moderate nuclear hyperchromasia, enlargement and pleomorphism (H&E, 200×).
Li et al. Diagnostic Pathology 2012 7:89 doi:10.1186/1746-1596-7-89