A new craniofacial disorder involving hypertelorism and malformations of external nose, palate and pituitary gland.

Abstract

The aim of the present study was to describe and pathologically evaluate an apparently unreported craniofacial malformation, based on comparison of the cranial midsagittal components with similar components under normal developmental conditions. A severely malformed fetus with a gestational age of about 17 weeks underwent whole body and special craniofacial radiography. Following autopsy dissection, the midsagittal segment of the cranial base, including the eyes, was radiographed in different projections. Midsagittal tissue blocks were serially sectioned for microscopy. Routine stains and immunohistochemical stains were applied. The face was characterized by hypertelorism, absence of external nose but with open shell-like cavities medio-cranially to the eyes, and by a palate fused in the midline and with extensive bony ridges laterally. There was absence of normal nasal cavities, presence of nasal septum and vomer, normal eyes, and nasal ducts covered with nasal mucosa ending blindly in the cartilage. No olfactory bulbs were found. The palatal ridges consisted of bony tissue. The pituitary gland was severely malformed and consisted solely of adenopituitary gland tissue, located in its full extent in the pharyngeal mucosa. There was no sella turcica. From a pathogenetic point of view, it is suggested that the neural crest cells in the frontonasal region of the crest were reduced in amount or late in migration to the midfacial region compared to the neural crest cells to the maxillary region. Therefore, we believe that the malformations observed in the nasal placodes and in the pituitary placode, combined with abnormal migration or abnormal timing of neural crest cells during the craniofacial development, are important factors behind this disorder.