RESUMEN
Invasive lobular carcinoma--comprising approximately 10 percent of breast cancers--is considered to be a histologically, molecular genetically, clinically distinct entity metastasizing mainly the gastrointestinal tract. Gastrointestinal system is much more likely involved in advanced invasive lobular carcinoma, than it is in invasive ductal carcinoma. They manifest after 3-20 years from the recognition of the primary tumor and they appear to be inflammatory disease or a secondary tumor. Here we show the case of a female patient with breast cancer, who died at the age of 53 years. 8 years after tumor-free state upper abdominal spastic pain emerged irradiating into the back with belt-like pattern. Radiologically, Crohn's disease was diagnosed. Ileum biopsy was negative. Patient was treated ex juvantibus with methylprednisolon. In the background of mechanic ileus the resection of the terminal ileum and partly the ascended colon was surgically removed. The patient died in 3 weeks after the operation. Microscopically the thickened wall of the terminal ileum showed diffuse small cell carcinomatous infiltration. Immuno-histochemically the metastatic carcinoma cells were reacting with Breast Carcinoma Antigen (BRCA 1) and CA 15-3. The patient had AB blood group according to her red blood cell phenotype. Lectins and monoclonal antibodies with ABH blood group specificity reacted strongly with the metastatic carcinoma cells.