Difficulties in recognizing hypothyroidism are amplified many times when the disease proceeds in unusual (non-classical) forms.
1.Hypertension in hypothyroidism. Hypertension is detected in 10-30% of patients with hypothyroidism. Its genesis is explained by vessel sensitization to endogenous pressor substances, a decrease in the level of atrial natriuretic factor and a number of other mechanisms. Replacement therapy with thyroid hormones in such patients contributes to lower blood pressure.
A rare option is the combination of hypothyroidism with sympatho-adrenal crises. Their intensity and frequency are significantly reduced when hypothyroidism is compensated.
2 Tachycardia with hypothyroidism. Tachycardia with untreated hypothyroidism may be associated with concomitant heart failure, anemia, decompensated insufficiency of the adrenal cortex, or other comorbidities. The appearance of tachycardia during the treatment of hypothyroidism is a sign of an overdose of thyroid hormones.
3 Polyserositis in hypothyroidism. Manifested by the accumulation of fluid in the cavity of the pericardium, pleura, sometimes the peritoneum in combination with the clinic of severe hypothyroidism. Most often we are talking about severe generalized autoimmune polyserosis, often in combination with a specific autoimmune pathology (anemia, hepatitis, etc.). Variants of polyserositis (or isolated pericarditis) with minimal clinical symptoms of hypothyroidism are described .
4. Hypothyroidism in autoimmune polyendocrine syndromes. The most common option is the combination of hypothyroidism, developed on the background of autoimmune thyroiditis, with primary chronic adrenal insufficiency (Schmidt syndrome) . This combination is a particular variant of type II autoimmune polyendocrine syndrome. which may also include type 1 diabetes, idiopathic hypoparathyroidism, primary hypogonadism, lymphocytic hypophysitis, isolated ACTH deficiency and / or LH / FSH. The syndrome is about 8 times more common in women, manifests on average at the age of 20-50 years, while the interval between the clinical debut of its individual components may be more than 20 years. Often the disease is combined with another autoimmune pathology: alopecia, B12 (folic) -deficient anemia, autoimmune thrombocytopenia, myasthenia, celiac disease, dermatomyositis, Parkinson’s disease. The combination with polyserositis, stiff – man syndrome is described. In most cases, autoimmune polyendocrine syndrome type II occurs sporadically, but many cases of familial forms have been described,which are characterized by autosomal dominant mode of inheritance with incomplete penetrance. HLA B 8, DR 3, DR 4 haplotypes are detected in many patients.
Sometimes primary hypothyroidism is combined with autoimmune polyendocrine syndrome of type I – a rare disease with an autosomal recessive mode of inheritance, less common sporadically, characterized by a triad: muco-cutaneous candidiasis, hypoparathyroidism, primary chronic adrenal insufficiency. This syndrome debuts, as a rule, in childhood, is somewhat more common in men.
5. The combination of hypothyroidism and pituitary adenoma. This combination may occur in the following situations:
a. Long-term decompensated primary hypothyroidism contributes to the formation of “secondary” TSH – or prolactin-secreting adenoma of the pituitary gland according to the mechanism of negative feedback. The degree of increase in the pituitary gland varies from hyperplasia to macroadena with chiasmatic syndrome. Replacement therapy with thyroid hormones helps to reduce the size of the adenohypophysis and the disappearance of the tumor.
b. Pituitary adenoma (both hormonally active and inactive) can lead to impaired TSH secretion and, therefore, secondary hypothyroidism.
6. The combination of hypothyroidism and the syndrome of “empty” Turkish saddle.
a. Syndrome “empty” Turkish saddle may occur against the background of replacement therapy for primary hypothyroidism. The latter leads to a decrease in the degree of hyperplasia of the pituitary gland, in this case there is a discrepancy between its size and the size of the Turkish saddle.
b. Syndrome “empty” Turkish saddle may be accompanied by hypothyroidism of central Genesis (secondary, tertiary). The cause of hypothyroidism in this case is a violation of the normal anatomical and functional relationships between the hypothalamus and the pituitary gland.
7 Syndrome of Van Vick-Grambach. It is a variant of the atypical course of hypothyroidism in childhood. Characterized by the dissociation of sexual development on the background of untreated or poorly treated hypothyroidism. In girls, it is possible to develop macromastia, galactorrhea, premature menarche with metrorrhages in the absence of sexual hair growth and delayed bone age. A similar male variant of the syndrome is characterized by accelerated development of the external genital organs in the absence or scarcity of sexual hair growth; frequent is the combination with Down’s disease. Frequent findings in children with Van Vick-Grambach syndrome are hyperprolactinemia and pituitary adenoma.