Abstract
Using in vitro methods, the G-banding pattern in a highly differentiated adenocarcinoma of the parotid gland is described. Results from 2 consecutive preparations of the carcinoma indicated that it had originated with a normal diploid stemline and subsequently during progression developed an aneuploid stemline deviating from the normal only by loss of the Y chromosome. From this hypodiploid stemline some clones and variant cells were generated, all of them characterized by numerical deviations, particularly various trisomies. Important cytogenetic similarities were found between the present adenocarcinoma and other types of salivary gland neoplasms, in particular pleomorphic adenomas.