Pituitary glandPituitary glandpathologypathology
Clinical Clinical mmanifestations anifestations of of ppituitary ituitary ddiseaseisease
HyperpituitarismHyperpituitarism
HypopituitarismHypopituitarism
Local mass effectsLocal mass effects
Most cases of Most cases of hypofunctionhypofunction arise from destructive processes directly involving arise from destructive processes directly involving the anterior pituitary the anterior pituitary ((although other mechanisms although other mechanisms have been identifiedhave been identified))..
-e-empty sella syndromempty sella syndrome
Infarct of the pituitaryInfarct of the pituitary
CONGENITAL CONGENITAL AND AND DEVELOPMENTAL DEVELOPMENTAL DISORDERSDISORDERS
Many Many transcription factorstranscription factors are implicated are implicated in pituitary organogenesis, in pituitary organogenesis, and abnormalities of these factors may result and abnormalities of these factors may result in congenital hypopituitarism.in congenital hypopituitarism.
Idiopathic GH deficiencyIdiopathic GH deficiency
CYSTIC LESIONSCYSTIC LESIONS
Rathke’s cleft cystsRathke’s cleft cysts
Arachnoid cystsArachnoid cysts
Dermoid and epidermoid cystsDermoid and epidermoid cysts
INFLAMMATORY DISORDERSINFLAMMATORY DISORDERS
Lymphocytic hypophysitisLymphocytic hypophysitis
Granulomatous hypophysitisGranulomatous hypophysitis
Xanthomatous hypophysitisXanthomatous hypophysitis
Secondary hypophysitisSecondary hypophysitis
may be due to infectious agents may be due to infectious agents or may occur as part of a systemic process or may occur as part of a systemic process such as sarcoidosis, such as sarcoidosis, vasculitis vasculitis (Takayasu’s Disease,Wegener’s granulomatosis), (Takayasu’s Disease,Wegener’s granulomatosis), Crohn’s disease, Crohn’s disease, or Whipple’s disease. or Whipple’s disease.
It has been associated with ruptured It has been associated with ruptured Rathke’s cleft cyst, Rathke’s cleft cyst, necrotizing adenoma, necrotizing adenoma, and meningitis.and meningitis.
Infections associated Infections associated with AIDSwith AIDS
may also involve the pituitary.may also involve the pituitary.
PITUITARY HYPERPLASIAPITUITARY HYPERPLASIA
may mimic adenoma.may mimic adenoma.
Somatotroph hyperplasiaSomatotroph hyperplasia
.. MammosomatotrophMammosomatotroph hyperplasiahyperplasia
Lactotroph hyperplasiaLactotroph hyperplasia
Corticotroph hyperplasiaCorticotroph hyperplasia
Thyrotroph hyperplasiaThyrotroph hyperplasia
Gonadotroph hyperplasiaGonadotroph hyperplasia
Although Although hyperplasiashyperplasias may have similar may have similar clinical presentations, a reticulin stain clinical presentations, a reticulin stain can reliably distinguish adenohypophysial can reliably distinguish adenohypophysial hyperplasia from adenoma. hyperplasia from adenoma.
PRIMARY TUMOURS OF PRIMARY TUMOURS OF ADENOHYPOPHYSEAL CELLSADENOHYPOPHYSEAL CELLS
The classification of pituitary adenomasThe classification of pituitary adenomas
requires correlation between clinical manifestationsrequires correlation between clinical manifestationsof hormone hypersecretion, of hormone hypersecretion, radiological determination of size and invasiveness, radiological determination of size and invasiveness, and tumour morphology. and tumour morphology. Tumour classification has been advanced Tumour classification has been advanced by the recognition of three main pathways by the recognition of three main pathways of adenohypophysial cytodifferentiation of adenohypophysial cytodifferentiation based on expression of transcription factors based on expression of transcription factors that regulate hormone genes.that regulate hormone genes.
The corticotroph pathwayThe corticotroph pathway
Somatotrophs, lactotrophs, Somatotrophs, lactotrophs, mammosomatotrophs, mammosomatotrophs, and thyrotrophsand thyrotrophs
ClassificationClassification
ADENOMAS ADENOMAS ASSOCIATED WITH ASSOCIATED WITH GROWTH HORMONE EXCESS GROWTH HORMONE EXCESS
Adenomas that produce GH excessAdenomas that produce GH excess with acromegaly or gigantismwith acromegaly or gigantism
represent up to 15% of pituitary adenomas. represent up to 15% of pituitary adenomas.
ADENOMAS ADENOMAS ASSOCIATED WITH ASSOCIATED WITH PROLACTIN EXCESS PROLACTIN EXCESS
THYROTROPH ADENOMAS THYROTROPH ADENOMAS ASSOCIATE WITH ASSOCIATE WITH TSH EXCESS TSH EXCESS
CORTICOTROPH ADENOMASCORTICOTROPH ADENOMASASSOCIATED WITH ASSOCIATED WITH ACTH EXCESS ACTH EXCESS
GONADOTROPH ADENOMAS GONADOTROPH ADENOMAS
CLINICALLY CLINICALLY NON-FUNCTIONING NON-FUNCTIONING PITUITARY ADENOMASPITUITARY ADENOMAS
PLURIHORMONAL PLURIHORMONAL PITUITARY ADENOMASPITUITARY ADENOMAS
PITUITARY CARCINOMA PITUITARY CARCINOMA
OTHER OTHER SSUPRASELLAR UPRASELLAR TUMORSTUMORS
Neoplasms in this location may induce Neoplasms in this location may induce hypofunction or hyperfunction of hypofunction or hyperfunction of the anterior pituitary, diabetes insipidus, the anterior pituitary, diabetes insipidus, or combinations of these manifestations. or combinations of these manifestations.
CraniopharyngiomaCraniopharyngioma
This benign, locally invasive tumour arises from remnants This benign, locally invasive tumour arises from remnants
Neuronal tumours, known as Neuronal tumours, known as gangliocytomasgangliocytomas are composed of mature neurones that resemble are composed of mature neurones that resemble hypothalamic ganglion cells. hypothalamic ganglion cells.
Gliomas of the sellar regionGliomas of the sellar region
MeningiomasMeningiomas
Granular cell tumoursGranular cell tumours
ChordomasChordomas
SchwannomasSchwannomas
UNUSUAL UNUSUAL PRIMARY TUMOURS PRIMARY TUMOURS
Germ cell tumoursGerm cell tumours
Hematologic neoplasmsHematologic neoplasms
Mesenchymal tumoursMesenchymal tumours
METASTATIC METASTATIC MALIGNANCIESMALIGNANCIES