Diagnosis of panhypopituitarism

In typical cases, the diagnosis of panhypopituitarism is simple. The appearance after complicated birth or in connection with another cause of the complex of symptoms of hypocorticism, hypothyroidism and hypogonadism testifies to the hypothalamic-pituitary insufficiency. Timely diagnosis is delayed in patients with Slightly Shyenic Syndrome, although the absence of lactation after labor accompanied by hemorrhage, prolonged decline in ability to work and violations of menstrual function should suggest hypopituitarism.

Diagnostic value has a number of laboratory indicators. Hypochromic and normochromic anemia can be noted, especially with severe hypothyroidism, sometimes with leukopenia with eosinophilia and lymphocytosis. When combined with diabetes insipidus, hypopituitarism is accompanied by a low relative density of urine. The level of glucose in the blood is low, and the glycemic curve with glucose load is flattened (hyperinsulinism). The content of cholesterol in the blood is increased. The proportion of adenohypophyseal hormones (ACTH, TSH, STH, LH and FSH) decreases in blood and urine.

If there is no possibility of direct determinations of hormones, indirect tests can be used. Thus, the reserve of ACTH in the pituitary is estimated from a sample with metopyron (Su = 4885), which blocks the biosynthesis of cortisol in the adrenal cortex, and by the mechanism of negative feedback, which causes an increase in the level of ACTH in the blood. Ultimately, the production of corticosteroids, the precursors of cortisol, mainly 17-hydroxy- and 11-deoxycortisol, is increasing. In urine, respectively, sharply increases the content of 17-ACS. With hypopituitarism, there is no significant reaction to the administration of metopyrone. The sample is made as follows: 750 mg of the drug in the granules is administered orally every 6 hours for 2 days. The content of 17-ACS in daily urine is examined before the test and on the second day of taking methopyrone.

The baseline level of corticosteroids in the blood and in the urine is usually reduced. With the introduction of ACTH, the content of corticosteroids increases in contrast to patients with Addison's disease, i.e., primary hypocorticism. However, for a long duration of the disease, the reactivity of the adrenal glands to ACTH injection gradually decreases. The presence of hypogonadism in women is indicated by a decrease in the level of estrogens, and in men - testosterone in the blood and urine.

Low basal metabolism, a decrease in the content of iodine bound to protein in the blood, or butanol-extractable iodine, free thyroxin, triiodothyronine, thyroid-stimulating hormone, and absorption of ¹³¹ I by the thyroid gland indicate a decrease in its functional activity. The secondary nature of hypothyroidism is confirmed by an increase in the accumulation of ¹³¹ I in the thyroid gland and the level of thyroid hormones in the blood after the administration of the thyroid-stimulating hormone.

The differential diagnosis of panhypopituitarism is not always simple. A number of diseases leading to weight loss (malignant tumors, tuberculosis, enterocolitis, sprue and spruce-like syndromes, porphyria), must be differentiated from hypothalamic-pituitary insufficiency. However, exhaustion in the above diseases, unlike the hypothalamic-pituitary, develops gradually, is the outcome of the disease, and not its dominant manifestation; only with impaired absorption in the intestine (sprue, enterocolitis, etc.), depletion may be accompanied by a secondary endocrine insufficiency.

The severity of anemia sometimes gives rise to differential diagnosis with blood diseases, and severe hypoglycemia can stimulate pancreatic tumors - insulinomas.

Primary hypothyroidism is excluded by a low level of thyroid-stimulating hormone in the blood and increased functional activity of the thyroid gland with the administration of exogenous thyroid-stimulating hormone.

Differential diagnosis of panhypopituitarism is particularly difficult in cases where primary hypothyroidism is complicated by impairments in the genital area and peripheral polyendocrine insufficiency (Schmidt's syndrome), including primary autoimmune damage to the adrenal gland, thyroid gland and often gonads.

In clinical practice, the most important is the differentiation of pituitary cachexia from exhaustion as a result of psychogenic anorexia that occurs in young girls and very rarely in young men due to a psychotraumatic conflict situation or with an active desire to lose weight and a violent refusal to eat. Decreased appetite until complete aversion to food is accompanied by psychogenic anorexia by the violation or disappearance of menstruation even before the development of severe depletion. Gradually, the sexual apparatus becomes atrophic, there are functional abnormalities on the part of the gastrointestinal tract and multiple symptoms of endocrine insufficiency. Decisive in differential diagnosis is anamnesis, the preservation of physical, intellectual and sometimes even creative activity with extreme exhaustion, the safety of secondary sexual characteristics in combination with deep atrophy of the genital organs.

[1], [2], [3], [4]