The reliability of radiology in detecting prolactin-secreting pituitary microadenomas

Radiological findings in 30 patients with proven prolactin-secreting pituitary adenomas, originally diagnosed exclusively by endocrine criteria, have been reviewed. Conventional tomography was the examination most often abnormal (50%), and changes or lack of changes corresponded to the state of the pituitary fossa as noted at operation in 93%. Tomographic abnormalities indicated the site of the tumour in 86%. Plain films were less sensitive (27% abnormal) although the changes reported were all confirmed during the surgical procedures. Although cavernous sinography and CT rarely yielded positive information unless either plain films or tomograms were abnormal, each may have a place in the assessment of a patient before operation: sinography to ensure that there is no significant anomaly of the carotid artery at the level of the pituitary fossa; CT scan to exclude a hypothalamic lesion or to detect an associated suprasellar tumour extension or intrasellar cisternal herniation. Strategies for the radiological investigation of patients suspected of having a prolactin-secreting pituitary tumour are proposed.