Signet-ring cell/histiocytoid carcinoma of the axilla: a clinicopathological and genetic analysis of 11 cases, review of the literature, and comparison with potentially related tumours.

The histopathological, immunohistochemical and genetic findings suggest that both types of SRCHC are phenotypic variants of AC, although there are differences in sex, macroscopic findings and the frequency of lymph node metastasis among the three. In contrast, ILC differs from the other three tumour types.