Talk:Endocrine - Pituitary Development

Evaluation of the Hypothalamic-Pituitary-Adrenal Axis Function in Childhood and Adolescence

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2790806/?tool=pubmed

Hypophyseal triplication: case report and embryologic considerations

AJNR Am J Neuroradiol. 2009 Aug;30(7):1328-9. Epub 2009 Mar 19.

Manara R, Citton V, Rossetto M, Padoan A, D'Avella D.

Neuroradiologic Unit, University Hospital of Padua, Padua, Italy. renzo.manara@sanita.padova.it Abstract SUMMARY: Hypophyseal triplication is malformation that has not been described previously. We present a child with midline abnormalities who underwent epignathus excision at birth. Brain MR imaging revealed 2 paired lateral pituitary glands and an oval midline gland, each with an independent stalk, connected to a thickened third ventricle floor. Because malformations represent a failure in embryogenesis, this case may provide interesting clues on the normal development of the hypophysis.

PMID: 19299490

http://www.ajnr.org/cgi/reprint/30/7/1328

Theory comparison

According to the classic theory,1,3,5 the hypophysis is believed to arise from 2 distinct structures, namely the diencephalic neuroectoderm (posterior lobe) and the oral ectoderm (anterior lobe). At approximately 42 days of gestation, a diverticulum originating from the stomodeum fuses with the downward extending diencephalic bud, both finally housed in the pituitary fossa.

In contrast to the traditional view, Gilbert (1934) found that in mammalian species, both the anterior and posterior part of the gland originate from the ventral neural ridge.1 In this model, resumed by Morton in 19574 in a case report of pituitary duplication, the gland is supposed to arise entirely from neuroectodermal tis- sue without the primary involvement of the Rathke pouch.

Duplication of the hypophyseal gland has been rarely described, often in association with several midline malformations.3,5 Most children do not survive beyond the neonatal period because of the severity of associated malformations.1

3. Kollias SS, Ball WS,PrengerEC.Reviewoftheembryologicdevelopmentofthe pituitary gland and report of a case of hypophyseal duplication detected by MRI. Neuroradiology 1995;37:3–12

5. Kandpal H,Seith A,PhilipJ,etal.Partialduplicationofthehypophysisinadult patients: report of 2 cases. J Comput Assist Tomogr 2007;31:365– 67