Page 567 - Concise Pathology for Exam Preparation ( PDFDrive )

552 SECTION II Diseases of Organ Systems

Clinical features

Presents mainly with manifestations of hypocalcaemia:
• Tetany, characterized by neuromuscular irritability (circumoral numbness, paraesthesias
of the distal extremities, carpopedal spasm, laryngospasm and generalized seizures)
• Mental status changes including emotional instability, anxiety, depression, confusion,
hallucinations and frank psychosis
• Intracranial manifestations include calcification of basal ganglia, Parkinson-like move-
ment disorder and increased intracranial pressure with resultant papilloedema
• Ocular disease (calcification of the lens resulting in cataract formation)
• Cardiovascular manifestations including conduction abnormalities
• Dental abnormalities (dental hypoplasia, failure of eruption, defective enamel and root
formation and abraded carious teeth)

ADRENAL GLANDS
• Paired endocrine organs
• Weigh about 4 g in adults
• Acute stress leads to lipid depletion, which causes decreased weight of the gland
• Three components:
• Capsule
• Cortex: Composed of:
• Zona glomerulosa
• Zona fasciculata (broad middle zone comprising more than 75% of the cortex)
• Zona reticularis
• Adrenal medulla: Composed of chromaffin cells, which synthesize and secrete cat-
echolamines
‘Adrenal cortex’ synthesizes three different types of steroids:
1. Glucocorticoids synthesized in zona fasciculata and zona reticularis
2. Mineralocorticoids synthesized in zona glomerulosa
3. Sex steroids synthesized in zona reticularis

Q. Write briefly on the pathogenesis, clinical features and morphology
of Cushing syndrome.
Ans. Cushing syndrome is a state of hypercortisolism (increased glucocorticoid levels).
Pathogenesis
Endogenous Cushing syndrome
• Primary hypothalamic–pituitary disease associated with hypersecretion of ACTH, also
called ‘Cushing disease’ (constitutes 70–80% cases of endogenous Cushing syndrome)
• Hypersecretion of cortisol by an adrenal adenoma, carcinoma or nodular hyperplasia
called ‘ACTH-independent Cushing syndrome’ (constitutes 10–20% cases of endog-
enous Cushing syndrome)
• Secretion of ectopic ACTH by a neuroendocrine neoplasm called paraneoplastic Cush-
ing syndrome seen in small cell carcinoma of the lung, carcinoid tumours, medullary
carcinoma thyroid and islet cell tumours of the pancreas
Exogenous or iatrogenic Cushing syndrome
Due to administration of exogenous corticosteroids.
Clinical Features
• Central obesity (upper trunk and back) with moon faces and buffalo hump
• Weakness and fatigability due to selective atrophy of fast twitch (Type II) myofibrils and
decreased muscle mass
• Hirsuitism and menstrual irregularities
• Hypertension
• Glucose intolerance/diabetes (induction of gluconeogenesis and decrease in uptake of
glucose by cells with resultant hyperglycaemia, glycosuria and polydipsia)
• Osteoporosis and skin striate (catabolic effect on proteins causing loss of collagen and
resorption of bone)
• Neuropsychiatric manifestations, eg, mood swings, depression and frank psychosis
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