Pathology of endocrine glands

Lesions

• atrophy• hypertrophy and hyperplasia• inflammation• neoplasia.

Atrophy and degeneration

Atrophy of thyroid is, in most cases , due to • lowered levels of the pituitary trophic hormones

TSH. • may result from loss of functional pituitary tissue • suppression of pituitary function by iatrogenic

administration of thyroid hormone

Atrophy of thyroid epithelium

•Distended follicles•flat epithelial cells• Absence of resorption vacuoles of the colloid at the border with the epithelium•absence of TSH stimulation•Hypophysectomy because of pituitary tumor

Hypertrophy and hyperplasia

• Diffuse hypertrophy and hyperplasia of thyroid or adrenals are associated with

• raised levels of TSH or ACTH• Inborn errors affecting the synthesis of hormones • Absence of a negative feedback to the pituitary

Parenchymatous goiter•(microfollicular hyperplasia)• Symmetrical enlargement due to diffuse microfollicular Hyperplasia•Small goat (cretin) with sporadic non-toxic goiter due to inability tosynthesize normal thyroglobulin and resulting in hypothyroidism. •Columnar follicular cell•small, even slit-like follicles with scanty colloid • papillaryproliferation

Colloid goitre•Symmetrical enlargement with severely distended follicles(cysts)•epithelial cells are flattened, the septa become atrophic •Locally, papillary proliferations occur and hypertrophic cells may still remain.• Sporadic non-toxic.

Hyperplasia of parathyroids

• Hyperplasia of parathyroids often indicates • a raised level of PTH. It results from hypocalcemia, but it may

be present even• when hypocalcemia is not present.• High levels of dietary calcium may induce hypertrophy and

eventually• hyperplasia of calcitonin-secreting parafollicular cells (C-cells).

Diffuse parathyroid hyperplasiaParathyroid glands attached to cranial pole of normal-sized thyroids.Bilateral diffuse enlargement of parathyroids Hyperplastic and slightly hypertrophic epithelial cellsforming sheets or cords, often arranged along blood vessels in apalisading fashion, with the apical cytoplasm directed towards thevessel (pseudoglandular appearance).

Adrenocortical atrophyAdrenal cortex•. Narrowed cortex composed of intact zona arcuata (A)•distinctlyatrophic zona fasciculata (Fl•The zona reticularis (R) isMainly made up of fatty remnants of disintegrated cortical cells.Unaffected medulla (M).ETIOLOGYIatrogenic chronic secondary hypoadrenalismafter longstanding glucocorticoid administration and suppression ofACTH-output

Adrenalitis•Adrenal cortex.• Round cell infiltrate (mainly lymphocytic) in adrenalcortex (zona arcuata and fasciculata) with destruction of corticaltissue. •Possibly due to autoimmunity. Leads to atrophy and Addison's disease.

Addison’s disease• Addison’s disease (also Addison disease, chronic adrenal

insufficiency, hypocortisolism, and hypoadrenalism) is a rare, chronic endocrine disorder in which the adrenal glands do not produce sufficient steroid hormones (glucocorticoids and often mineralocorticoids).

• The condition arises from problems with the adrenal gland, primary adrenal insufficiency, and can be caused by damage by the body's own immune system,

Suppurative hypophysitisHead, median section.• Abscess (arrow) below the cranial cavity in the sella turcica and covered by the diaphragma sellae. •Remnants of thepituitary in centre of abscess

Pituitary tumor

Brain• Large, red, tumorous mass (arrows), just behind the optic chiasm. •Histologically, proliferation of basophilic cells. •clinical signs related to increased intracranial pressure•Tumor composed of basophilic cells. • A few pre-existing acidophilic cells(arrow). Cushing'ssyndrome.

Cushing,s syndrom

• refers to a pituitary-dependent cause of Cushing's syndrome: a tumor (adenoma) in the pituitary gland produces large amounts of ACTH, causing the adrenal glands to produce elevated levels of cortisol. It is the most common non-iatrogenic cause of Cushing's syndrome

• This can be caused by taking glucocorticoid drugs, or diseases that result in excess cortisol, adrenocorticotropic hormone (ACTH), or CRH levels.