The sinus reaction in the axillary nodes in breast cancer related to tumour size and nodal state.

The sinuses of the axillary nodes were studied in 59 breast cancer patients. Three types of reaction were defined in them; sinus histiocytosis, a mixed sinus reaction, and sinus catarrh. Sinus histiocytosis, as defined here, was virtually confined to the mode-negative cases; sinus catarrh, common to both node-negative and positive, but increasing with tumour size in the former. It is suggested that transition may occur from sinus histiocytosis, via the mixed reaction, to sinus catarrh, and that the establishment of the latter may facilitate tumour spread.