Latent malignancies at autopsy: a little used source of information on cancer biology.

Latent carcinomas, found incidentally at autopsy, are defined, and information about such tumours in the prostate, adrenal gland, kidney and thyroid is reviewed. A previously unsuspected carcinoma of the prostate was found in 350 of 1327 (26.4%) autopsies performed in seven countries on men over 45 years of age. The prevalence of latent carcinoma of the prostate at autopsy was greater in older men and in areas of higher incidence and/or mortality, as for clinical carcinomas. Neuroblastomas of the adrenal gland have been reported at a rate of 1:39 in newborn infants who died of other causes; this rate is comparable to that of latent prostatic carcinoma. Neuroblastomas are not found in the adrenal glands of infants older than three months, indicating that the body has a method for destroying them. Latent carcinomas are also found in the thyroid gland at autopsy, at rates ranging from 10 to 30%. The age and area differences seen for prostatic carcinoma do not appear to be operative for these tumours; moreover, latent carcinomas are found more frequently in males, whereas the clinical disease is twice as frequent in females. More research should be carried out to elucidate the differences between people who develop clinical carcinoma, those who have a latent carcinoma 'under control' and those who have neither.