Hyperpituitarism is the result of excess secretion of adenohypophyseal trophic hormones most commonly by a functional 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...

. Other causes are hyperplasia

Hyperplasia

Hyperplasia means increase in number of cells/proliferation of cells. It may result in the gross enlargement of an organ and the term is sometimes mixed with benign neoplasia/ benign tumor....

s and carcinoma

Carcinoma

Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...

s of the adenohypophysis, secretion by non-pituitary tumours and certain hypothalamic disorders.

Clinical manifestations

Depending on the cell type(s) affected, clinical manifestations of hormone excess may include:

• Hyperprolactinaemia
  Hyperprolactinaemia
  Hyperprolactinaemia or hyperprolactinemia is the presence of abnormally-high levels of prolactin in the blood. Normal levels are less than 500 mIU/L for women, and less than 450 mIU/L for men....
  
  
• Cushing's disease
  Cushing's disease
  Cushing's disease is a cause of Cushing's Syndrome characterised by increased secretion of adrenocorticotropic hormone from the anterior pituitary. This is most often as a result of a pituitary adenoma...
  
  
• Precocious puberty
  Precocious puberty
  As a medical term, precocious puberty describes puberty occurring at an unusually early age. In most of these children, the process is normal in every respect except the unusually early age, and simply represents a variation of normal development. In a minority of children, the early development is...
  
  
• Gigantism
  Gigantism
  Gigantism, also known as giantism , is a condition characterized by excessive growth and height significantly above average...
  
   or Acromegaly
  Acromegaly
  Acromegaly is a syndrome that results when the anterior pituitary gland produces excess growth hormone after epiphyseal plate closure at puberty...
  
  
• Hyperthyroidism
  Hyperthyroidism
  Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...
  
   (rare)

Associated conditions

When there is an enlargement of the pituitary tissue, hyperpituitarism is often associated with:

• Visual field
  Visual field
  The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical...
  
   defects, classically bitemporal hemianopia
  Bitemporal hemianopsia
  Bitemporal hemianopsia is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field...
  
  
• Radiographic abnormalities of the sella turcica
  Sella turcica
  -External links:*...
  
  , such as sellar expansion, bony erosion and disuption of the diaphragma sellae
  Diaphragma sellae
  The diaphragma sellae or sellar diaphragm is the circular fold of dura mater that almost completely roofs the fossa hypophyseos of the sella turcica of the sphenoid bone within the skull. It retains the pituitary gland in the fossa hypophyseos, with only the infundibulum of the pituitary gland...
  
  
• Increased intracranial pressure

Symptoms

Symptoms caused by hormone excess and associated mass effects include:

• Headache
  Headache
  A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
  
  
• Visual field loss or Double vision
  Diplopia
  Diplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
  
  
• Excessive sweating
• Hoarseness
• Milk secretion from breast
  Breast
  The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...
  
  
• Sleep apnea
  Sleep apnea
  Sleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...
  
  
• Carpal tunnel syndrome
  Carpal tunnel syndrome
  Carpal Tunnel Syndrome is an entrapment idiopathic median neuropathy, causing paresthesia, pain, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel. The pathophysiology is not completely understood but can be considered compression...
  
  
• Joint pain and limitation of motion
• Muscle weakness
  Muscle weakness
  Muscle weakness or myasthenia is a lack of muscle strength. The causes are many and can be divided into conditions that have true or perceived muscle weakness...
  
  
• Numbness or tingling of skin