Pituitary gland duplication syndrome - An international imaging analysis

Ulrike Löbel; Martin Catala; Felice D'Arco; Maarten H Lequin; Rossella Pasquariello; Pilvi Ilves; Dagmar Loorits; Annika Tähepõld; Giulio Pezzetti; Ian Craven; Mariasavina Severino; Andrea Rossi

doi:10.3174/ajnr.A8534

Pituitary gland duplication syndrome - An international imaging analysis

AJNR Am J Neuroradiol. 2024 Oct 11:ajnr.A8534. doi: 10.3174/ajnr.A8534. Online ahead of print.

Affiliation

¹ From the Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, UK (U.L.,F.D.), Laboratory of Developmental Biology, CNRS, Sorbonne-University, IPBS, Paris, France (M.C.), Department of Radiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas, United States (M.H.L.), Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy (R.P.), Department of Radiology, Tartu University Hospital, Tartu, Estonia (P.I., D.L., A.T.), Department of Radiology, The University of Tartu, Tartu, Estonia (P.I.), UOC Neuroradiologia, ASST Papa Giovanni XXIII, Bergamo, Italy (G.P.), Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK (I.C.), Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy (M.S., A.R.) and Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy (A.R.).

PMID: 39393841
DOI: 10.3174/ajnr.A8534

Abstract

Background and purpose: Duplication of the pituitary gland is a rare developmental anomaly. Multiple associated craniofacial malformations have previously been reported with the largest series to date consisting of five patients. In this multi-institutional series of ten patients, we present a detailed review of the imaging features and discuss a possible overarching pathogenesis that would explain most of the detected malformations.

Materials and methods: Inclusion criteria for this retrospective imaging review were the presence of a pituitary stalk and gland duplication and the characteristic appearance of the hypothalamic ventral midline. In addition to the clinical presentation, we recorded the imaging findings of ten patients (9 female) through onsite and online reviews. Genetic analysis was available for six patients.

Results: The duplicated pituitary stalk and gland showed normal imaging appearances in all patients. Mammillary bodies were clearly identified lateral to the characteristic prominence of the hypothalamic ventral midline. Strands of tissue extending to the anterior dura ("limited ventral myeloschisis") were noted at the medulla oblongata in 10, and at the cervical spinal cord in 7 patients. The medulla oblongata showed a "butterfly" appearance on axial images in 9 patients. Ten patients had cervical segmentation anomalies ("zipper"-like), 9 anterior-posterior brainstem patterning defects (small pons, elongated medulla), and corpus callosum measurements were abnormal in all patients. Three patients each presented with diencephalic-mesencephalic junction abnormalities and 4 with an anterior mesencephalic "cap". An oropharyngeal teratoma was present in four patients. Genetics was normal in three of the six patients studied; the remainder were found to have mutations in EFNB1 and a gene variant of GIT1, two copies of 7. And 8. exon of SMN1 gene, and 2.126 megabase duplication at bands q11.1 and q11.2 of one chromosome 15, respectively.

Conclusions: Duplication of the pituitary gland presents as well-defined craniofacial and cervical spine malformation phenotype. Axial mesoderm duplication generating an excess of Sonic Hedgehog may be the primary embryological driver leading to this condition.

Abbreviations: CFNS＝ Craniofrontonasal Syndrome; DPG＝ Duplication of the Pituitary Gland; SHH＝ Sonic Hedgehog.