Mucin embolism to cerebral arteries: a fatal complication of carcinoma of the breast.

The case is reported of a woman with a mucin producing lobular carcinoma of the breast with metastases to many bone sites, whose terminal neurological illness was the result, not of cerebral metastases, but of cerebral infarcts. These were caused by emboli of mucin and emulsified fat, originating in bone metastases. The pathogenesis of this embolism is compared with that of traumatic fat embolism. Attention is drawn to this process because emboli of this type have never been reported and because this distant nonmetastatic effect of carcinoma may have been overlooked in other cases. It is suggested that this mechanism should be considered in the diagnosis of otherwise obscure cerebral infarction.