Pseudolymphoma of breast.

A lymphoid infiltrate in the breast of a 77-year-old woman exhibited histological features warranting a diagnosis of pseudolymphoma. Detection of surface markers on cell suspensions of the lesion revealed approximately equal numbers of B aand T cells and kappa and lambda light chains in the immunoglobulins of the former. This represents ancillary evidence that is consonant with the pseudolymphomatous nature of the infiltration. Recognition of pseudolymphoma of the breast as an entity appears significant from practical and theoretical standpoints and is relevant to considerations concerning the incidence of so-called primary lymphoma of this organ.