[Neurosurgery and pituitary tumors: etio-pathogenic considerations]. / La neurochirurgie et les tumeurs hypophysaires. Considérations étio-pathogéniques.

PITUITARY ADENOMA: Based on the experience of nearly 5000 cases of surgically treated pituitary tumors at the neurosurgery department of the Foch Hospital, the pituitary adenoma is the most frequent pituitary tumor. Secreting tumors lead to a clinical syndrome depending on the level of hormone overproduction. Gonadotrop or non-functioning pituitary adenomas are mainly macroadenomas presenting with visual symptoms, hypopituitarism or as an incidentaloma. Anatomical features dictate the surgical approach. OTHER TUMORS: The other types of hypophyseal tumors, such as craniopharyngioma, Rathke's cleft cyst or others are usually surgical tumors because medical treatment is ineffective. Malignant pituitary tumors are unusual.

P53 protein accumulates in Cushings adenomas and invasive non-functional adenomas.

The p53 protein, a negative regulator of cell growth, plays an important role in the pathogenesis of many human tumours following gene mutation and/or deletion. We screened a large number of sporadic pituitary tumours for p53 protein accumulation suggestive of gene mutation. Samples were divided into benign adenomas (n = 95) and invasive tumours with local or distant invasion (n = 26). All main tumour classes were represented. Putative p53 mutations were detected by immunohistochemistry on paraffin-embedded sections using polyclonal CM-1 and monoclonal DO-7 and PAb1801 antibodies. Results were compared to normal post-mortem pituitary tissue controls (n = 17). p53 protein accumulation was detected in invasive tumours (16%), but only in corticotrophinomas (2/4) and non-functional tumours (4/15). In non-invasive adenomas, protein accumulation was observed only in ACTH-secreting tumours where 50% were positive (16/32). No protein accumulation was identified in any control tissue. These results indicate that p53 protein accumulation may play a role in the development of Cushings adenomas and in the progression of non-functional tumours to the invasive state.

p53 Protein accumulates in Cushings adenomas and invasive non-functional adenomas.

The p53 protein, a negative regulator of cell growth, plays an important role in the pathogenesis of many human tumours following gene mutation and/or deletion. We screened a large number of sporadic pituitary tumours for p53 protein accumulation suggestive of gene mutation. Samples were divided into benign adenomas (n = 95) and invasive tumours with local or distant invasion (n = 26). All main tumour classes were represented. Putative p53 mutations were detected by immunohistochemistry on paraffin-embedded sections using polyclonal CM-1 and monoclonal DO-7 and PAb1801 antibodies. Results were compared to normal post-mortem pituitary tissue controls (n = 17). p53 protein accumulation was detected in invasive tumours (16%), but only in corticotrophinomas (2/4) and non-functional tumours (4/15). In non-invasive adenomas, protein accumulation was observed only in ACTH-secreting tumours where 50% were positive (16/32). No protein accumulation was identified in any control tissue. These results indicate that p53 protein accumulation may play a role in the development of Cushings adenomas and in the progression of non-functional tumours to the invasive state.

An acth-secreting pituitary tumour arising in a patient with congenital adrenal hyperplasia.

The case reported is of a 46-year-old woman who had congenital adrenal hyperplasia due to a 21-hydroxylase deficiency, and in whom there was the development of an ACTH secreting pituitary tumour. The patient was untreated with glucocorticoids until the age of 32 years when she presented with infertility. She next presented with amenorrhoea at the age of 44 years when she was found to have an enlarged pituitary fossa. Despite treatment with bromocriptine and adequate doses of dexamethasone, the tumour enlarged and required operative treatment 1 year later. Before and after operation, plasma ACTH levels were between 300 and 400 ng/l, immunocytochemistry showed staining for ACTH and other structurally related pro-opiocortin peptides but for no other hormones, and the tumour secreted large amounts of ACTH in vitro. The report of this case is to our knowledge the first account of a feedback tumour in congenital adrenal hyperplasia and provides yet another reason why patients with this condition should be treated, and good control achieved.

Postadrenalectomy pituitary adenoma (Nelson's syndrome) in childhood: clinical and roentgenologic detection.

Following total adrenalectomy in Cushing's syndrome associated with adrenal hyperplasia, but not with adrenal adenoma or malignancy, elements of the pituitary may be stimulated to grow rapidly and even aggressively. There is strong evidence to support the idea that there is a pre-existing tumor in many, if not all, of these cases. In some, the tumor may be too small to deform the sella turcica. After adrenalectomy, these patients should be observed carefully and frequently for hyperpigmentation, visual field defects, and sella turcica enlargement.