Cytokeratin 7 negative invasive breast carcinoma: clinicopathological and immunohistochemical analysis of 14 cases with clinical follow-up

Abstract

Cytokeratin 7 (CK 7) negative breast tumours are reported to occur rarely. We studied 14 CK 7 negative cases of primary invasive ductal carcinoma (IDC) detected during sentinel lymph node metastases work-up and immunohistochemistry panel in the work-up of metastatic carcinoma of unknown origin. Axillary lymph node metastases were present in seven patients (50%). Oestrogen receptor (ER) was strongly positive in all cases: progesterone receptor in 78%, Her-2/neu in 7% and high proliferation index with Ki-67 >20% was seen in 71% of the cases. Metastatic and/or recurrence were found in 8 of 14 patients (57%) with the mean clinical follow-up of 55 months. Metastatic sites include multiple bones, brain, spinal cord, liver, pancreas, ovary, lung, lymph node other than ipsilateral axillary and skin. 12 of 14 patients received adjuvant chemotherapy. All 14 patients received hormonal therapy and radiation therapy. Morphologically, IDC with neuroendocrine features was noted in 57%. Synaptophysin stain was positive in 57% and chromogranin was positive in 21% of the cases. In conclusion, these CK 7 negative breast carcinomas were ER positive, mostly Her-2/neu negative, had high Ki-67 and frequently showed neuroendocrine differentiation. More than half of these cases had a poor outcome.

Solid papillary carcinoma of the breast with an associated Cytokeratin 7- negative Paget's disease of the nipple. Report of a first case

“…According to literature data, this constellation has not been reported so far. In a study by Moatamed et al., 14 cases of CK7 negative breast tumors were investigated, of which more than 50% showed a neuroendocrine immunophenotype, however, SPC or MPD were not included . Recently, two cases of CK7‐negative MPD have been described, none of which showed a neuroendocrine differentiation.…”

A Note of Caution

“…9 However, there are rare cases of breast carcinoma that are negative for CK7 reported in the literature. 10 The use of broad spectrum cytokeratins is, therefore, recommended to screen for metastatic breast carcinoma in SLNB. However, one pitfall in relying on pan-keratin cocktails is presuming they provide comprehensive broad spectrum coverage of cytokeratins and that this spectrum is consistent across manufacturers.…”

Immunohistochemistry of mammary Paget’s disease

“…In addition, it is important to note that CK7-negative breast carcinoma and MPD are rare but do exist and could prove potentially problematic in confirming the diagnosis of MPD. 7,8 In recent years, GATA-binding protein 3 )GATA3( was reported to express in breast carcinomas, MPD and extramammary Paget's disease. 9,10 Furthermore, human epidermal growth factor receptor 2 )HER2( is overexpressed in majority of the MPD cases.…”