Accumulation of Hormones in Breast Cyst Fluid*

The concentration of some immunoreactive peptide hormones in breast cyst fluid and serum from a series of patients with cystic breast disease were compared. The concentrations of the two pituitary gonadotropins, LH and FSH, were consistently higher in serum than in cyst fluid, confirming earlier more limited observations. The mean PRL concentration, on the other hand, was elevated in cyst fluid though the variability was great. The cyst fluid serum ratio of hCG was elevated in the patient group as a whole. However, the results suggested the presence of two subpopulations; group I, in which the cyst fluid and serum hCG levels were essentially indistinguishable and in the range found in normal serum, and group II, in which the cyst fluid hCG concentration was consistently greater than the normal serum range. Analysis of hormone concentrations in multiple cysts aspirated at the same time showed a remarkable degree of agreement in the cyst hormone levels in most of the patients. The greatest variability in the levels was seen with hCG, were a small numer of subjects showed a very large spread in the values.