Tall cell carcinoma of the breast with reversed polarity - a report of three cases with a review of the literature.

Tall cell carcinoma with reverse polarity (TCCRP) is a rare special type of breast epithelial neoplasm presented by columnar cells with opposite nuclear polarity, solid and solid-papillary architecture, and frequent IDH2 gene alterations. Hereby, the authors present three cases of TCCRP in women aged 56, 66 and 67 years with maximum tumour sizes of 29 mm, 10 mm and 8 mm. Tumours showed histomorphological characteristics of TCCRP supported by immunohistochemical profile of tumour cells, in which positive expression of CK7, CK5/6, GCDFP15, mammaglobin, GATA3 and calretinin and negativity of CK14, p63, TTF1, thyroglobulin and neuroendocrine markers were demonstrated.