Objectives: The aim of this study was to examine pituitary adenomas in a large collective of postmortem
pituitaries by use of modern technologies of immunostaining, to classify the adenomas
according to the current WHO classification and to analyze possible associations to
available clinical data.
Methods: In this study pituitaries of 3048 cases obtained from autopsy series of the years
1991 to 2004 were examined. Detailed immunohistochemical staining followed for prolactin
(PRL), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), luteinizing
hormone (βLH), α-subunit, S-100 protein and MIB-1. The available clinical data were
analysed.
Results: A total of 334 pituitary adenomas were found in 316 pituitaries. 132 sparsely granulated
prolactinomas (39.5%), 75 null cell adenomas (22.5%) and 31 oncocytomas were diagnosed.
46 ACTH cell adenomas (13.8%, 27 densely granulated, 19 sparsely granulated) and one
adenoma composed of Crooke's cells were detected. 22 gonadotroph cell adenomas (6.6%),
seven GH cell adenomas (4 sparsely granulated, 3 densely granulated), one mixed GH
cell-PRL cell adenoma, two TSH cell adenomas, five plurihormonal adenoma type I, four
plurihormonal adenoma type II and two α-subunit-only adenomas were seen. Six adenomas
remained unclassified because the tissue was not contained in all sections for immunohistochemistry.
17 pituitaries included multiple tumours. The overall tumour size ranged from 0.1
to 20mm in diameter. 138 tumours had a tumour size of 1mm or less, only three tumours
were macroadenomas corresponding to a size of more than 10mm. The evaluation of available
clinical data showed 99 cases of hypertension, 65 cases of diabetes mellitus, six
patients with hyper- and four with hypothyroidisms. No symptoms of adenohypophyseal
hormone hypersecretion were reported. The statistical evaluation showed no significant
correlations to clinical data.
Conclusion: Adenomas in postmortem pituitaries differ from those in surgical series in regard
to adenoma types, functional properties and biological behaviour.