| Pituitary adenoma Classification and external resources | |
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| ICD-10 | D35.2 |
| ICD-9 | 237.0 |
| ICD-O: | M8140/0 |
| MedlinePlus | 000704 |
| eMedicine | neuro/312 |
| MeSH | D010911 |
Pituitary adenomas are tumors that occur in the pituitary gland, and account for about 10% of intracranial neoplasms. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The International Classification of Diseases for Oncology (ICD-O is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems The International Classification of Diseases for Oncology (ICD-O is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic The pituitary gland, or hypophysis, is an Endocrine gland about the size of a Pea. They often remain undiagnosed, and small pituitary tumors are found in 6 to 24 percent of adults at autopsy. An autopsy, also known as a post-mortem examination, necropsy, or obduction, is a Medical procedure that consists of a thorough Examination
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Types
Pituitary tumors were, historically, classed as basophilic, acidophilic, or chromophobic on the basis of whether or not they took up the stains hematoxylin and eosin. Basophilic is a technical term used by histologists. It describes the microscopic appearance of cells and tissues as seen down the Microscope, The term chromophobe refers to Histological structures which do not take up colored dye readily and thus appear more relatively pale under the microscope -- hence their "fear" Haematoxylin, hematoxylin, Natural Black 1, or CI 75290 is extracted from the wood of the Logwood tree Eosin is a Fluorescent red Dye resulting from the action of Bromine on Fluorescein. This classification has fallen into disuse, in favor of a classification based on what type of hormone is secreted by the tumor (though tumors which do not secrete any active hormone ("non-functioning tumors") are still sometimes called "chromophobic"). Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body
At present, classification of pituitary tumors is based on plasma hormone levels or immunohistochemical staining:
| Type of adenoma | Secretion | Staining | Pathology |
| corticotrophic adenomas | secrete adrenocorticotropic hormone (ACTH) and pro-opiomelanocortin (POMC) | basophilic | Cushing's disease |
| somatotrophic adenomas | secrete growth hormone (GH) | acidophilic | acromegaly (gigantism) |
| thyrotrophic adenomas (rare) | secrete thyroid-stimulating hormone (TSH) | basophilic | occasionally hyperthyroidism, usually doesn't cause symptoms |
| gonadotrophic adenomas | secrete luteinizing hormone (LH), follicle-stimulating hormone (FSH) and their subunits | basophilic | usually doesn't cause symptoms |
| lactrotrophic adenomas or prolactinomas (most common) | secrete prolactin | acidophilic | galactorrhea, hypogonadism, amenorrhea, infertility, and impotence |
| null cell adenomas | do not secrete hormones | may stain positive for synaptophysin |
Diagnosis
The diagnosis is generally entertained either on the basis of visual difficulties arising from the compression of the optic nerve by the tumor, or on the basis of manifestations of excess hormone secretion: the specifics depend on the type of hormone. Immunohistochemistry or IHC refers to the process of localizing proteins in cells of a tissue section exploiting the principle of antibodies binding specifically Corticotropes (or corticotrophs are cells in the Anterior pituitary which produce Adrenocorticotrophic hormone and Melanocyte stimulating hormone Adrenocorticotropic hormone ( ACTH or corticotropin) is a Polypeptide Hormone produced and secreted by the Pituitary gland Pro-opiomelanocortin ( POMC) is a precursor Polypeptide with 241 Amino acid residues An anterior pituitary basophil is a type of cell in the Anterior pituitary which manufactures Hormones. Somatotropes are cells in the Anterior pituitary which produce Growth hormone. Growth hormone ( GH) is a Peptide hormone that stimulates growth and cell reproduction in humans and other animals An acidophile (or acidophil, or as an adjectival form acidophilic) describes is a term used by Histologists to describe a particular staining pattern of Acromegaly (from Greek akros "extreme" or "extremities" and megalos "large" - extremities enlargement is a Syndrome Thyrotropes are cells in the Anterior pituitary which produce Thyroid stimulating hormone. Thyroid-stimulating hormone (also known as TSH or thyrotropin) is a Peptide hormone synthesized and secreted by Thyrotrope cells in the An anterior pituitary basophil is a type of cell in the Anterior pituitary which manufactures Hormones. Hyperthyroidism is the term for overactive tissue within the Thyroid gland resulting in overproduction and thus an excess of circulating free thyroid hormones Thyroxine Gonadotropes are basophilic cells in the Anterior pituitary which produce the Gonadotropins Follicle-stimulating hormone (FSH and Luteinizing hormone ( LH, also known as lutropin) is a Hormone produced by the Anterior pituitary gland. Follicle-stimulating hormone ( FSH) is a Hormone synthesized and secreted by Gonadotropes in the Anterior pituitary gland. An anterior pituitary basophil is a type of cell in the Anterior pituitary which manufactures Hormones. Lactotrophs (also known as lactotrope mammatroph mammotroph epsilon acidophil prolactin cell and lactotropic cell are cells in the Anterior pituitary which produce A prolactinoma is a Benign Tumor ( Adenoma) of the Pituitary gland that produces a Hormone called Prolactin. Prolactin ( PRL) or Luteotropic hormone ( LTH) is a Peptide hormone primarily associated with Lactation. An acidophile (or acidophil, or as an adjectival form acidophilic) describes is a term used by Histologists to describe a particular staining pattern of Galactorrhea or galactorrhoea is the spontaneous flow of Milk from the Breast, unassociated with Childbirth or nursing Hypogonadism is a medical term for a defect of the Reproductive system that results in lack of function of the Gonads ( ovaries or testes) Amenorrhoea ( BE) amenorrhea ( AmE) or amenorrhœa, is the absence of a Menstrual period in a woman of reproductive age Female infertility|Male infertility Infertility primarily refers to the biological inability of a Man or a Woman to contribute to conception. A null cell is a large granular Lymphocytes without surface markers or membrane-associated proteins from B lymphocytes or T lymphocytes. Synaptophysin, also known as SYP, is a human Gene. The protein encoded by this gene is a Synaptic vesicle Glycoprotein with four transmembrane The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain. The specific area of the visual pathway at which compression by these tumours occurs is at the optic chiasma. The optic chiasm ( Greek χίασμα "crossing" from the Greek χλαζειν 'to mark with an X' after the Greek letter ' Χ ' chi) is the
The anatomy of this structure causes pressure on it to produce a defect in the temporal visual field on both sides, a condition called bitemporal hemianopia. Bitemporal hemianopsia (or Bitemporal hemianopia) is the medical description of a type of partial Blindness where vision is missing in the outer half of both the right
Tumors which cause visual difficulty are likely to be macroadenomata greater than 10 mm in diameter; tumors less than 10 mm are microadenomata.
Some tumors secrete more than one hormone, the most common combination being GH and prolactin.
Prolactinomas are frequently diagnosed during pregnancy, when the hormone progesterone increases the tumor's growth rate. Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body Progesterone is a C-21 Steroid Hormone involved in the Female Menstrual cycle, Pregnancy (supports Gestation Headaches may be present. The diagnosis is confirmed by testing hormone levels, and by radiographic imaging of the pituitary (for example, by CT scan or MRI). Computed tomography (CT is a Medical imaging method employing Tomography.
Treatment
Treatment options depend on the type of tumor and on its size:
- Prolactinomas are most often treated with bromocriptine or more recently, cabergoline which, unlike bromocriptine, decreases tumor size as well as alleviates symptoms, both dopamine agonists, and followed by serial imaging to detect any increase in size. A prolactinoma is a Benign Tumor ( Adenoma) of the Pituitary gland that produces a Hormone called Prolactin. Bromocriptine (brand names include Parlodel an Ergoline derivative is a Dopamine agonist that is used in the treatment of Pituitary Tumors Cabergoline (brand names Dostinex and Cabaser an ergot derivative is a potent Dopamine receptor Agonist on D2 receptors Treatment where the tumor is large can be with radiation therapy or surgery, and patients generally respond well. Radiation therapy (or radiotherapy) is the medical use of Ionizing radiation as part of Cancer treatment to control Malignant Efforts have been made to use a progesterone antagonist for the treatment of prolactinomas, but so far have not proved successful. An antagonist (from Greek ανταγωνιστής - antagonistes, "opponent competitor rival" is a character or
- Thyrotrophic adenomas respond to octreotide, a long-acting somatostatin analog, in many but not all cases according to a review of the medical literature. Somatostatin (also known as growth hormone inhibiting hormone ( GHIH) or somatotropin release-inhibiting factor ( SRIF) is a Peptide hormone Unlike prolactinomas, thyrotrophic adenomas characteristically respond poorly to dopamine agonist treatment. [1]
References
- ^ a Chanson, Philippe; Weintraub, Bruce D. ; and Harris, Alan G. (1993) Octreotide Therapy for Thyroid-Stimulating Hormone-Secreting Pituitary Adenomata. Annals of Internal Medicine 119 (3), 236-240.
External links
- Cancer.gov: pituitary tumors
- Case report of Bilateral Hemianopsia Due to Pituitary Adenoma. Clinical Cases and Images.
- Medical Illustration of Pituitary Adenomas by Frank H. Netter
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