Exencephaly-Anencephaly Sequence Associated with Maxillary Brachygnathia, Spinal Defects, and Palatoschisis in a Male Domestic Cat

Abstract

Anencephaly, a severe neural tube defect characterized by the absence of major parts of the brain and skull, is a rare congenital disorder that has been observed in various species, including cats. Considering the uncommon appearance of anencephaly, this paper aims to present anencephaly in a stillborn male kitten from an accidental inbreeding using various paraclinical methods. Histological examination of tissue samples from the cranial region, where parts of the skull were absent, revealed the presence of atypical nerve tissue with neurons and glial cells organized in clusters, surrounded by an extracellular matrix and with an abundance of blood vessels, which are large, dilated, and filled with blood, not characteristic of nerve tissue structure. In CT scans, the caudal part of the frontal bone, the fronto-temporal limits, and the parietal bone were observed to be missing. CT also revealed that the dorsal tubercle of the atlas, the dorsal neural arch, and the spinal process of the C2-C7 bones were missing. In conclusion, the kitten was affected by multiple congenital malformations, a combination of exencephaly-anencephaly, maxillary brachygnathism, closed cranial spina bifida at the level of cervical vertebrae, kyphoscoliosis, palatoschisis, and partial intestinal atresia. The importance of employing imaging techniques cannot be overstated when it comes to the accurate diagnosis of neural tube defects.

Keywords: anencephaly; congenital malformations; exencephaly; feline; neural tube defects.

Figure 1

Head, dorsal view, stillborn kitten fetus. The brain tissue was covered by a reddish membrane (a). The whole body of the kitten, dorsal view, scoliosis is visible (b). Head, rostral view, shallow orbits with protrusion of the globes, and maxillary brachygnathia (c). Lateral view with the umbilical cord with a segment from the colon visible (marked with *) (d). Palatoschisis, severe form—marked with an arrow (e).

Figure 2

Histological sections: (a) ← neurons, H.E. staining, 40× ob; (b) ← neurons, ← glial cells, H.E. staining, 100× ob; (c) ← blood vessels, H.E. staining, 20× ob; (d) ← large blood vessel with various diameters, 20× ob.

Figure 3

Radiographic image of the kitten: (A) Partial absence of skull bones, (B) kyphoscoliosis. There is no abdominal serosal detail due to lack of abdominal fat. The gastrointestinal gas is not visible to provide a contrast.

Figure 4

CT scan with VRT images of the kitten’s skull.

Figure 5

CT with VRT images of the kitten: (a) Complete spine image, (b) cervical vertebra with no dorsal arches/lamina.

Figure 6

CT scan with MPR images of the skull. (a) Tympanic bulla, first cervical vertebral, atlas and occipital condyles; (b) first cervical vertebral and atlas; (c) the eye, maxilla (more exactly, nasal bone), palate bone, and mandibula.