Difference between revisions of "Pituitary gland"
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**GH, PRL. | **GH, PRL. | ||
*Basophils (10% of cells) = basophilic (light blue). | *Basophils (10% of cells) = basophilic (light blue). | ||
**TSH, LH, FSH. | **TSH, LH, FSH, ACTH. | ||
*Chromophobes (50% of cells) = amphophilic (purplish/grey). | *Chromophobes (50% of cells) = amphophilic (purplish/grey). | ||
Revision as of 05:20, 16 March 2011
The pituitary gland is known as the master gland.
Divisions:[1]
- Anterior pituitary (AKA adenohypophysis).
- Posterior pituitary (AKA neurohypophysis, neural pituitary).
Function
Anterior
Hormones:[2]
- Growth hormone (GH).
- Luteinizing hormone (LH)
- Follicle-stimulating hormone (FSH)
- Thyroid stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
- Prolactin (PRL)
Mnemonic: "Go Look For The Adenoma Please" = GH, LH, FSH, TSH, ACTH, PRL.
Posterior
Hormones:[2]
- Oxytocin.
- Antidiuretic hormone (ADH).
Anatomy and histology
Anatomy
Basic anatomy (simplified):[3]
- Anterior:
- Pars distalis.
- Pars intermedia.
- Posterior:
- Pars nervosa.
Embryological origin:[3]
- Anterior - Rathke's pouch (roof of mouth).
- Posterior - diencephalon (ventral aspect).
Images:
Histology
Anterior
- Acidophils (40% of cells) = red or orange.
- GH, PRL.
- Basophils (10% of cells) = basophilic (light blue).
- TSH, LH, FSH, ACTH.
- Chromophobes (50% of cells) = amphophilic (purplish/grey).
Notes:
- The cellular product (i.e. hormone produced) is not strictly correlated with the cell type.[4]
- The cells can be typed using IHC; somatotrophs (GH), lactotrophs (PRL), corticotrophs (ACTH), thyrotrophs (TSH), gonadotrophs (FSH, LH).[5]
Posterior
Features:[4]
- Herring bodies - key feature.
- Eosinophilic axonal dilations filled with lysosomes and neurosecretory granules.
- Less cellular.
- Usually more cellular in perivascular location.
Image: Herring bodies (ouhsc.edu).
DDx for stellar lesions
- Pituitary adenoma.
- Rathke cleft cyst.
- Craniopharyngioma.
- Germ cell tumour.
- Meningioma.
Pituitary adenoma
General
- Classically presents with visual field defects.
- May be part of multiple endocrine neoplasia I
- 3Ps: pituitary adenoma, parathyroid adenoma, pancreatic neuroendocrine tumours.
Microscopic
Features:[6]
- Loss of fibrous stroma.
- The cells of a normal (anterior) pituitary are nested.
Notes:
- Smears very well.[7]
Rathke cleft cyst
General
- Benign counterpart of craniopharyngioma.
- Arises from intermediate lobe of pituitary gland (pars intermedia of pituitary gland).
Radiology:
- Typically no calcifications.[8]
Radiologic DDx:[8]
- Arachnoid cyst.
- Craniopharyngioma.
- Cysticercosis (see microorganisms).
- Pituitary adenoma.
- Epidermoid of brain.
Microscopic
Features:
- Lined by a layer of cuboidal or columnar epithelial with cilia.
- +/-Goblet cells.[9]
- +/-Squamous metaplasia ~ may be several layers thick.
- May be confused with papillary craniopharyngioma.[10]
Image: Rathke's cleft cyst (endotext.org).
Craniopharyngioma
General
- Develop from remains of Rathke's pouch or squamous epithelial cell rests.[11]
Comes in two flavours:[11]
- Adamantinomatous type.
- Squamous papillary type.
- Usu. older individuals.
Radiology:[11]
- Calcified (adamantinomatous type).
- Solid & cystic.
Microscopic
Adamantinomatous
Features (adamantinomatous):[12]
- Well-circumscribed (or pseudoinvasive border).
- Multicystic.
- Small-to-medium sized cells with moderate amount of basophilic cytoplasm.
- Bland nuclei (with occ. small nucleoli).
- "Wet" keratin - nests of whorled keratin.
- Calcifications (non-psammomatous).
Images:
- Adamantinomatous craniopharyngioma - very low mag. (WC).
- Adamantinomatous craniopharyngioma - intermed. mag. (WC).
- Adamantinomatous craniopharyngioma - very high mag. (WC).
Papillary
Features (papillary):[13]
- Non-keratinized squamous epithelium (without nuclear atypia).
- Fibrovascular cores (required for papillary).
Notes:
- +/-Cilia (rare).
- +/-Goblet cell-like formations (rare).
Image:
- Papillary craniopharyngioma - intermed. mag. (WC).
- Papillary craniopharyngioma - very high mag. (WC).
- Craniopharyngioma (med.utah.edu).[14]
Necrosis
- Rare.
Causes
- Sheehan syndrome - secondary to blood loss in childbirth.[15]
- Syphilis (fetal-maternal transmission).[16]
- Mollaret's meningitis - very rare.[17] (???)
- Spontaneous necrosis of pituitary tumours - case reports.[18]
Autoimmune hypophysitis
General
Features:[19]
- Rare.
- Autoantigens are unknown.
- May be misdiagnosed as a nonsecreting adenoma.
Microscopic
Features:[19]
- Lymphocytic infiltration.
See also
References
- ↑ http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/hypopit/histo.html
- ↑ 2.0 2.1 http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pituitary.html
- ↑ 3.0 3.1 URL: http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/hypopit/histo_pit.html. Accessed on: 31 October 2010.
- ↑ 4.0 4.1 Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 26. ISBN 978-0443069826.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1098-9. ISBN 978-1416031215.
- ↑ Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 36. ISBN 978-0443069826.
- ↑ MUN. 24 November 2010.
- ↑ 8.0 8.1 URL: http://emedicine.medscape.com/article/343629-overview. Accessed on: 14 November 2010.
- ↑ URL: http://www.endotext.org/neuroendo/neuroendo3/neuroendo3.html. Accessed on: 27 May 2010.
- ↑ Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 408. ISBN 978-0443069826.
- ↑ 11.0 11.1 11.2 Garnett, MR.; Puget, S.; Grill, J.; Sainte-Rose, C. (2007). "Craniopharyngioma.". Orphanet J Rare Dis 2: 18. doi:10.1186/1750-1172-2-18. PMID 17425791.
- ↑ Tadrous, Paul.J. Diagnostic Criteria Handbook in Histopathology: A Surgical Pathology Vade Mecum (1st ed.). Wiley. pp. 184. ISBN 978-0470519035.
- ↑ Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 406. ISBN 978-0443069826.
- ↑ URL: http://library.med.utah.edu/WebPath/jpeg4/ENDO115.jpg. Accessed on: 6 December 2010.
- ↑ URL: http://www.mayoclinic.com/health/sheehans-syndrome/DS00889. Accessed on: 16 November 2010.
- ↑ URL: http://pediatrics.aappublications.org/cgi/content/full/104/1/e4. Accessed on: 16 November 2010.
- ↑ Dancer CM, Woods ML, Henderson RD, Robertson T, Mungomery M, Allworth A (July 2008). "Mollaret's meningitis and pituitary failure associated with a Rathke's cleft cyst". Intern Med J 38 (7): 609–11. doi:10.1111/j.1445-5994.2008.01709.x. PMID 18715308.
- ↑ Sachdev Y, Evered DC, Hall R (April 1976). "Spontaneous pituitary necrosis". Br Med J 1 (6015): 942. PMC 1639254. PMID 1268492. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1639254/pdf/brmedj00512-0028a.pdf.
- ↑ 19.0 19.1 Tzou SC, Lupi I, Landek M, et al. (July 2008). "Autoimmune hypophysitis of SJL mice: clinical insights from a new animal model". Endocrinology 149 (7): 3461–9. doi:10.1210/en.2007-1692. PMC 2453094. PMID 18388197. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453094/.
External links
- Neuropathology - neuropathologyweb.org.
- Endocrine histology (anhb.uwa.edu.au).