CUSHING'S SYNDROME -CAUSES, CLINICAL FEATURES,INVESTIGATIONS AND TREATMENT

                                             Cushing’s Syndrome

Syndrome produced when excess amount of glucocorticoids is produced.

MNEMONICS

C-  Central obesity(truncal) and moon face

U-  urination excess-Polyurea,ploy dyspsia

S-  Striae(purple)

H- Hypertension/hirsutism

I-  Increased protein metabolism ,so reduced CHO metabolism-Diabetes

N-  + Na retention,oedema hypokalemia

G-  glycosuria with insulin resistant Diabetes mellitus

Syndr

O- osteoporosis

M-  Moon face,myopahy

E-Easy bruising

Cushin’s syndrome is  produced when excess amount of glucocorticoid is produced.

Pituitary dependent  disease is called Cushings disease

CAUSES:

I.Adrenal hyperplasia

A. secondary to pituitary hypothalamic dysfunction

B.Secondary to ACTH producing tumors

i) Pituitary tumors

ii) non endocrine tumors like bronghogenic carcinoma

II. Adrenal nodular hyperplasia

III.Adrenal neoplasia

i)                    Adenoma

ii)                  Carcinoma

IV.Exogenous(iotrogenic)

i)                    Prolonged use of glucocorticoids

ii)                  Prolonged use of ACTH

CLINICAL FEATURES

i)Typical habitus with obesity of the trunk,moon face with buffalo hump

ii)Increased body weight ,muscle weakness and fatigability.

iii)                Hypertension

iv)                Hirsutism

v)                  Amonorrhea

vi)                Cutaneous striae,ecchymosis,acne

vii)              Personality changes

viii)            Polyurea,polydipsia

INVESTIGATIONS and LABORATARY FINDINGS:

i)                    Circulating eosinophils below 100cells per cubic mm

ii)                  Generalised osteo porosis  best made out in pelvis and spine

iii)                Diabetes/impaired glucose tolerence

iv)                Elevated plasma and urinary 17-hydroxy corticoid

v)                  (normal urinary level being 2-10 mg/24hrs) with loss of diurnal excretory pattern

Etiological diagnosis of Suspected Cushing’s syndrome

Alternative screening tests

a   i )      Plasma cortisol(8A.M)> 5µg/100ml after 1mg dexamethasone at night-not suppressed as in normal people.

b   ii )     Urinary 17-OH>10mg per 24 hrs

c   iii  )      Urinary free cortisol>100 µg in 24hrs

d   iv )     Plasma cortisol showing absent diurnal variation

.Other tests

electrolytes may show hypokalemia

Glucose intolerance may be present

Hypertension may be present

CXR–to exclude bronchial carcinoma

ACTH levels

High in pituitary disease, very high in ectopic ACTH syndrome-

Low in adrenal disease

CT scan of pituitary and adrenals identifies tumors.

Sample from inferior petrosal sinus for ACTH localizes pituitary tumors

TREATMENT

 Surgery 

Indication :

 for most pituitary and adrenal tumors

Some cases of  ectopic ACTH syndrome

In cases not amenable to surgery-

Metapyrone and amino-glut –ethimide which inhibits cortisol production may help.

The above drugs are also used preoperatively.

For cushings disease –radiotherapy to pituitary.

Iotrogenic cushings syndrome –responds to reduction in steroid dosage.In such cases Azathioprine may be used in conjunction to reduce dose of  steroids.

Note:

Cushings Syndrome is potentially fatal if untreated,so  patients must be fllowed up regularly.

But most can be treated effectively and can also be cured.