Pickardt-syndrome denotes a rare form of tertiary hypothyroidism

Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

 that is caused by interruption of the portal veins

Hypophyseal portal system

The hypophyseal portal system is the system of blood vessels that link the hypothalamus and the anterior pituitary in the brain.It allows endocrine communication between the two structures. It is part of the hypothalamic-pituitary-adrenal axis. The anterior pituitary receives releasing and...

 connecting hypothalamus

Hypothalamus

The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...

 and pituitary.

It was characterized in 1972 and 1973.

Etiology

Interruption of the portal system may be caused by tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

s compressing the infundibulum. Other causes for Pickardt's syndrome are inflammatory disorders

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 and traumatic brain injury

Traumatic brain injury

Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...

. An inborn variant of Pickardt's syndrome that is associated with certain mutations (HESX1

HESX1

Homeobox expressed in ES cells 1, also known as homeobox protein ANF, is a homeobox protein that in humans is encoded by the HESX1 gene.Expression of HEX1 and HESX1 marks the anterior visceral endoderm of the embryo...

 or LHX4

LHX4

LIM/homeobox protein Lhx4 is a protein that in humans is encoded by the LHX4 gene.-Further reading:...

) is referred to as pituitary stalk interruption syndrome (PSIS).

Endocrine consequences

Typical manifestations of Pickardt-Fahlbusch syndrome are hypothyroidism with reduced TSH values and functional hyperprolactinemia (which is caused by disinhibition of prolactin

Prolactin

Prolactin also known as luteotropic hormone is a protein that in humans is encoded by the PRL gene.Prolactin is a peptide hormone discovered by Henry Friesen...

 release). Other endocrine disorders that are usually associated with Pickardt syndrome are suprasellar failures like secondary hypogonadism

Hypogonadism

Hypogonadism is a medical term for decreased functional activity of the gonads. Low testosterone is caused by a decline or deficiency in gonadal production of testosterone in males...

, reduced levels of growth hormone

Growth hormone

Growth hormone is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior...

 and, in more severe cases, secondary adrenal insufficiency

Adrenal insufficiency

Adrenal insufficiency is a condition in which the adrenal glands, located above the kidneys, do not produce adequate amounts of steroid hormones , primarily cortisol, but may also include impaired aldosterone production which regulates sodium, potassium and water retention...

.

Diagnosis

Pickardt's syndrome may cause difficulties in differential diagnosis of pituitary adenoma

Pituitary adenoma

Pituitary adenomas are tumors that occur in the pituitary gland, and account for about 15% of intracranial neoplasms. Tumors which exceed 10 mm in size are defined as macroadenomas, and those smaller than 10 mm are referred to as microadenomas...

s, as both suprasellar hormone-inactive adenomas and prolactinoma

Prolactinoma

A prolactinoma is a benign tumor of the pituitary gland that produces a hormone called prolactin. It is the most common type of pituitary tumor...

s may be associated with increased prolactin levels, central hypgogonadism and central hypothyroidism. Usually, the prolactin levels are higher in case of a true prolactinoma, but the concentration ranges overlap.

Therapy

Treatment modality depends from the etiology

Etiology

Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

. Tumors may be removed surgically, but pituitary stalk interruption may persist. Usually, replacement of those hormone

Hormone

A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

s that are reduced due to failed feedback control systems will be necessary.