Nuclear DNA content in breast carcinomas with neuroendocrine differentiation

Sixty-one breast carcinomas (54 infiltrating ductal carcinomas and seven infiltrating lobular carcinomas) were immunostained with anti-NSE and analysed with respect to nuclear DNA content. Nine of the 23 NSE-positive breast carcinomas were diploid, five were triploid, six tetraploid and three pentaploid. Twenty-one of the 38 NSE-negative tumours were diploid, 10 were triploid, seven tetraploid, and none were pentaploid. Three of the eight histologically grade I tumours in the NSE-positive group were aneuploid, whereas all the six grade I tumours in the NSE-negative group were diploid. The results show that a proportion of breast carcinomas with neuroendocrine differentiation are aneuploid and that aneuploid tumours that are grade I histologically are found in the NSE-positive group and not in the NSE-negative group.