Duplicated Pituitary Gland and Odontoid Process

Abstract

The development of the pituitary gland is not well understood, but duplication of the gland, a rare embryonic anomaly, may shed some light on the process. Since 1880 only about 40 cases have been described. A 56-year-old woman complained of chronic bilateral upper extremity paresthesia and numbness along her first three fingers relieved by rest and exacerbated by increased activity. Magnetic resonance imaging of her head and neck showed an incidental discovery of a duplication of the pituitary infundibulum and pituitary fossa. Computed tomography of the neck showed congenital fusion of C2 with C3, C4 with C5, C1 with the occipital bone, and a duplication of the odontoid process. Her physical examination and all laboratory data were negative. Only seven patients with a pituitary duplication have ever survived beyond puberty. While all of these patients had normal mental capabilities, they also all had obvious craniofacial malformations. Unlike our patient, all other reported cases of duplicated pituitaries have been associated with abnormalities of the face or brain. Previously proposed theories for duplicated pituitary glands include failed twinning, teratogens, and an extreme form of the median cleft face syndrome. We feel that the cleft theory developed by Morton et al. best describes the cause of our patient's malformations. Such anomalous presentations will improve our understanding of how the pituitary gland develops and the order in which cranial structures develop to cause these cranial malformations.

The odontoid process: a comprehensive review of its anatomy, embryology, and variations

“…It is thought to result from the traction of the apical ligament on the tip of the odontoid process during the early process of development of the craniovertebral junction when the apical ligament is less rudimentary [21,25]. Studies have shown anteversion angles to have a range of 60-105°w ith a mean of 95° [24]. However, the odontoid may also be retroflexed (Fig.…”

“…19 and 20) is extremely rare and tends to occur in the presence of duplicated pituitary gland [5]. Results from faulty interactions among the notochord, prechordal plate and surface endoderm [19,24], with evidence of bony discontinuity of the posterior arch of C1, and a hypertrophied anterior arch are seen on CT [7]. The duplication possibly results from a lack of fusion of ossification centers, but definite etiologic factors are currently unknown.…”

Duplication of the odontoid process with other congenital defects of the craniocervical Junction: case report and review of the literature

“…Duplication of the odontoid process remains an uncommon developmental pathology that has been reported rarely in the literature [1][2][3][4]. This variant has previously been linked to cases of pituitary gland duplication and Klippel-Feil syndrome, although the exact etiology and pathogenesis are incompletely understood [2,3,5].…”

“…Many other anatomical variations have been reported in relation to odontoid malformation, the most common being os odontoideum [1]. Other reported congenital or acquired variants of the odontoid process include hypoplasia, aplasia, anteversion, malposition, odontoid process bicornis, ossiculum terminale, and fused nonseparated odontoid process to the anterior arch of the atlas [1,4,5].…”

“…Most of the case reports currently available within the literature describe complete duplication of the odontoid process, most commonly in conjunction with fusion of adjacent cervical vertebrae, atlas deformities, and pituitary duplication [1][2][3][4]. A single report describing a syndromic patient noted duplication of the C2 body in addition to duplication of the odontoid process [3].…”