Duplication of the pituitary gland - plus syndrome

Inspired by a patient

Sen D, Arora V. Duplication of the pituitary gland - plus syndrome. Indian J Radiol Imaging. 2016 Jan-Mar;26(1):126-30.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4813062/

Abstract

Duplication of the pituitary gland (DPG) is a very rare developmental anomaly that is often associated with other anomalies - the DPG-plus syndrome and occurs due to splitting of the rostral notochord and prechordal plate during blastogenesis. DPG with the constellation of associated anomalies as in our patient has not been reported previously. This article illustrates the importance of imaging the brain in all patients with obvious midline facial anomalies and the complementary role of MRI and CT in such cases.

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From the article

Duplications of internal organs are rare. They occur either due to non-union of anlages or division of the primordial organ. Duplication of the pituitary gland (DPG) is a very rare developmental anomaly, with only 40 cases reported till 2012.  With DPG as the common denominator, a large number of associated anomalies have been reported - the DPG-plus syndrome.  In this article, we report a case of pituitary duplication that was associated with duplication of the sella, hypertelorism, cleft palate, a large craniopharyngeal canal and oropharyngeal teratoma, hypoplastic olfactory bulbs and tracts, duplication of the basilar artery, and cervical anterior cleft vertebrae. DPG with this constellation of associated anomalies in the same patient has, to the best of our knowledge, not been reported previously…

DPG is a very rare developmental anomaly with only 40 cases reported till 2012. It has been reported in both the pediatric and adult populations. Most patients are females. DPG is usually detected in unsuspected patients on imaging due to the associated midline craniofacial anomalies.

The rarity of this entity may hence be partially attributable to incidental detection on imaging and early mortality in some patients. While most patients have been diagnosed in the neonatal period, later detection has been due to evaluation for anosmia, delayed onset of puberty and menarche, and precocious puberty.

DPG is frequently associated with multiple other craniofacial defects like broadening or duplication of the sella, broadening of the optic chiasma, duplication of the infundibulum, tubo-mamillary fusion (hypothalamic pseudohamartoma), duplication of the basilar artery, agenesis/hypoplasia of the corpus callosum, hypertelorism, cleft palate, craniopharyngeal canal, oropharyngeal teratomas, and vertebral segmentation anomalies.  Other rare associations that have been reported include duplication of the lips, tongue, mandible; a wide cribriform plate; absent olfactory bulbs and/or tracts; cerebellar hypoplasia; ventricular enlargement; pontine hypoplasia; neuronal migration abnormalities; and supernumerary teeth.  Apart from anomalies of the head and neck region, congenital diaphragmatic hernia has been associated with DPG. The high association of these craniofacial anomalies with DPG is suggestive of a polytopic blastogenesis defect, and hence, Manjila, et al. have proposed the term DPG-plus syndrome…

Thus, these anomalies in our patient as well as the spectrum of other associated anomalies in DPG-plus syndrome can all be explained based on the theory of rostral notochordal splitting during blastogenesis. MRI of the brain is essential in all patients with obvious midline facial anomalies. T1W, T2W and fluid attenuated inversion recovery (FLAIR) axial, and T2W sagittal and coronal images should be acquired in all such patients. The field-of-view (FOV) during acquisition of the sagittal and coronal images should be such as to include the cervical spine. Detection of tubo-mamillary fusion should prompt a dedicated sellar imaging protocol. These sequences may be supplemented by non-contrast and contrast-enhanced fat-suppressed images when a craniopharyngeal mass is detected. Vascular anomalies detected on T2W axial and coronal images may be better delineated by 3D-Time of Flight (3D-TOF) MR angiography (MRA). CT scan has a complementary role as it better delineates osseous craniofacial anomalies and affords 3D reconstructions and surface rendering for pre-surgical planning. Due to the high association of flow-related aneurysms with duplications and fenestrations, periodic surveillance for aneurysms is also warranted.

Notwithstanding the rarity of associated anomalies outside the central nervous system or the spine, a chest radiograph and an abdominal USG should be considered…

DPG is a very rare developmental anomaly that occurs due to splitting of the rostral notochord and prechordal plate during blastogenesis. It is often associated with a large number of associated craniofacial anomalies and, hence, the appellation the DPG-plus syndrome. This case illustrates that it may be worthwhile imaging the brain in all patients with obvious midline facial anomalies and a dedicated sellar protocol in the presence of tubo-mamillary fusion. While MRI is the primary modality of imaging in such patients, the complementary role of CT scan is also highlighted.