Higher levels of estrogens may be protective in the breasts of young girls, which are less likely to contain malignant cells, but harmful in older women, whose breasts are more likely to have acquired transformed cells.
While breast fluids may contain diluted quantities of malignant cells and genetic alterations, they harbor concentrated mixtures of proteins reflecting the epithelial, stromal, and infiltrating cell populations of the breast microenvironment.
The present study was undertaken to test if the CD44+CD24neg/low breast cancer stem cell population may contain heterogeneous subsets of differing malignant potential that could subvert effective therapeutic targeting.
The 14 g core-cut biopsies taken in most of our studies may contain a million or more malignant cells, in contrast to the 1,000 cells that we routinely score in a single section; this much larger cell population might be assessed by molecular means in an extract of the core-cut, and this would theoretically give much greater analytical precision.
Based on previous investigations of series of BRCA1 mutation-positive patients [ 3] the primary, metastatic and recurrent tumors will frequently exhibit complete loss of heterozygosity (LOH), and therefore the mutant allele frequency in the tumors should be close to 1, instead of 0.57 - 0.76, suggesting that the tumor samples may contain considerable proportion of non-malignant tissue.
Although frequently benign, they may contain carcinoma in situ or be frankly malignant with features of malignant degeneration including irregularity of the wall and thick septa with solid nodules [28].
Dysgerminomas are malignant and appear as solid masses, which may contain cystic areas with haemorrhage or necrosis[ 32 ].
For example, methods such as RT PCR or Western blotting which use tissue extracts may contain a contribution from cells other than those derived from the malignant component of the tumour.
Since proflavine stains nuclei, images containing malignant cells may have a higher intensity than images of normal lymphatic tissue.
The urine may contain hemoglobin or its derivatives after hemolysis (liberation of hemoglobin from red blood cells), after incompatible blood transfusion, and in malignant malaria (blackwater fever).
