[Diffuse splenic metastasis of occult breast cancer with incompatible blood group antigenic determinants].

Introduction: Cancer cells with immunogenic properties having modified blood group substances are widely studied (Kannagi, 1988, Hakomori, 1999).

Case Report: A 78-year-old female patient was admitted to the hospital in terminal state with unsusceptible circulatory failure. At autopsy the spleen (weight: 420 g) was extremely firm with diffuse blackberried colored cut surface. There were no signs of carcinomatous process at autopsy.

Material/method: By histology the spleen showed diffuse metastatic carcinomatous infiltration. Antibody to Breast carcinoma antigen (BioGenex) labelled metastatic cells of the spleen and bone marrow. The patient had O blood group according to her blood group phenotype. The authors used lectins with and without blood group antigen (BGA) specificity and monoclonal antibodies, too.

Results: They found that the B blood group specific Bandeiraea simplicifolia agglutinin I lectin and the anti-B mab were labelled intensively all the metastatic cells of spleen and bone marrow. The A BGAs (with anti-A mab and Dolichos biflorus agglutinin) were completely negative.

Conclusions: These observations raise the possibility that the detected incompatible B blood group antigen determinants on the metastatic cells were immunogenic. The authors propose, that the survived carcinoma cells found place of refuge from the immune surveillance in the spleen and in the bone marrow, where the complement mediated tumor cell lysis, immune-rejection was not effective.