Disorders of Pituitary Gland

 DISORDERS OF PITUITARY GLAND

HYPERACTIVITY OF ANTERIOR PITUITARY

1. Gigantism

Gigantism is the pituitary disorder characterized by excess growth of the body. The subjects look like the giants with average height of about 7 to 8 feet.

Disorders of Pituitary Gland


Causes

Gigantism is due to hypersecretion of GH in childhood or in pre-adult life before the fusion of epiphysis of bone with shaft. Hypersecretion of GH is because of tumor of acidophil cells in the anterior pituitary.

Signs and symptoms

i. General overgrowth of the person leads to the development of a huge stature, with a

height of more than 7 or 8 feet. The limbs are disproportionately long

ii. Giants are hyperglycemic and they develop glycosuria and pituitary diabetes. Hyperglycemia

causes constant stimulation of β-cells of islets of Langerhans in the pancreas and release of

insulin. However, the overactivity of β-cells of Langerhans in pancreas leads to degeneration

of these cells and deficiency of insulin and ultimately, diabetes mellitus is developed

iii. Tumor of the pituitary gland itself causes constant headache

iv. Pituitary tumor also causes visual disturbances.

It compresses the lateral fibers of optic chiasma, leading to bitemporal hemianopia

2. Acromegaly

Acromegaly is the disorder characterized by the enlargement, thickening and broadening of bones,

particularly in the extremities of the body.

Causes

Acromegaly is due to hypersecretion of GH in adults after the fusion of epiphysis with shaft of the bone.

Hypersecretion of GH is because of tumor of acidophil cells in the anterior pituitary.

Signs and symptoms

i. Acromegalic or gorilla face: Face with rough features such as protrusion of supraorbital

ridges, broadening of nose, thickening of lips, thickening and wrinkles formation on forehead and prognathism (protrusion of lower jaw)

ii. Enlargement of hands and feet

iii. Kyphosis (extreme curvature of upper back – thoracic spine)

iv. Thickening of scalp. Scalp is also thrown into folds or wrinkles like bulldog scalp

v. Overgrowth of body hair

vi. Enlargement of visceral organs such as lungs, thymus, heart, liver and spleen

vii. Hyperactivity of thyroid, parathyroid and adrenal glands

viii. Hyperglycemia and glucosuria, resulting in diabetes mellitus

ix. Hypertension

x. Headache

xi. Visual disturbance (bitemporal hemianopia).

3. Acromegalic Gigantism

Acromegalic gigantism is a rare disorder with sym ptoms of both gigantism and acromegaly.

Cushing Disease

It is also a rare disease characterized by obesity.

Causes

Cushing disease develops by basophilic adenoma of adenohypophysis. It increases the secretion of adrenocorticotropic hormone, which in turn stimulates the adrenal cortex to release cortisol. Cushing disease also develops by hyperplasia or tumor of adrenal cortex.

HYPOACTIVITY OF ANTERIOR PITUITARY

1. Dwarfism

Dwarfism is a pituitary disorder in children, characterized by the stunted growth.

Causes

Reduction in GH secretion in infancy or early childhood causes dwarfism. It occurs because of the following reasons:

i. Tumor of chromophobes: It is a non-functioningtumor, which compresses and destroys the normal

cells secreting GH. It is the most common cause for hyposecretion of GH, leading to dwarfism

ii. Deficiency of GH-releasing hormone secreted by hypothalamus

iii. Deficiency of somatomedin C

iv. Atrophy or degeneration of acidophilic cells in the anterior pituitary

iv. Panhypopituitarism: In this condition, there is reduction in the secretion of all the hormones

of anterior pituitary gland. This type of dwarfism is associated with other symptoms due to the

deficiency of other anterior pituitary hormones.

Signs and symptoms

i. Primary symptom of hypopituitarism in children is the stunted skeletal growth. The maximum

height of anterior pituitary dwarf at the adult age is only about 3 feet

ii. But the proportions of different parts of the body are almost normal. Only the head becomes

slightly larger in relation to the body

iii. Pituitary dwarfs do not show any deformity and their mental activity is normal with no mental

retardation

iv. Reproductive function is not affected, if there is only GH deficiency. However, during panhypopituitarism, the dwarfs do not obtain puberty due to the deficiency of gonadotropic hormones.

Acromicria

Acromicria is a rare disease in adults characterized by the atrophy of the extremities of the body.

Causes

Deficiency of GH in adults causes acromicria. The secretion of GH decreases in the following conditions:

i. Deficiency of GH-releasing hormone from hypothalamus ii. Atrophy or degeneration of acidophilic cells in the anterior pituitary

iii. Tumor of chromophobes: It is a non-functioning tumor, which compresses and destroys the

normal cells secreting the GH. This is the most common cause for hyposecretion of GH leading

to acromicria

iv. Panhypopituitarism: In this condition, there is a reduction in secretion of all the hormones of

anterior pituitary gland. Acromicria is associated with other symptoms due to the deficiency of

other anterior pituitary hormones.

Signs and symptoms

i. Atrophy and thinning of extremities of the body, (hands and feet) are the major symptoms in

acromicria

ii. Acromicria is mostly associated with hypothyroidism

iii. Hyposecretion of adrenocortical hormones also is common in acromicria

iv. The person becomes lethargic and obese

v. There is loss of sexual functions.

3. Simmond Disease

Simmond disease is a rare pituitary disease. It is also called pituitary cachexia.

Causes

It occurs mostly in panhypopituitarism, i.e. hyposecretion of all the anterior pituitary hormones due to the atrophy or degeneration of anterior pituitary.

Symptoms

i. A major feature of Simmond disease is the rapidly developing senile decay. Thus, a 30- years-old person looks like a 60-years-old person. The senile decay is mainly due to deficiency of hormones from target glands of anterior pituitary, i.e. the thyroid gland, adrenal cortex and the gonads

ii. There is loss of hair over the body and loss of teeth

iii. Skin on face becomes dry and wrinkled. So, there is a shrunken appearance of facial features. It is

the most common feature of this disease.

 

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