Frontoethmoidal meningoencephalocele with multiple congenital craniofacial and skeletal malformations in a stillborn puppy

Abstract

A one-and-a-half-year-old Shih-Tzu bitch went into natural labor after full term of her first pregnancy, giving birth to 4 puppies. One of them was a male which died at birth, 104 grams in weight and 12 centimeters in length. This puppy showed several facial abnormalities and skeletal deformities. It was preserved in 10% formalin for anatomical, histopathological, and radiographic studies. Gross anatomical study revealed congenital anomalies of the eyes including anophthalmia of the left eye and microphthalmia of the right eye. Malformations of the ears including anotia of the left ear and microtia of the right ear were observed. Evidence of cleft lips was also noted. There was a membrane-bound mass emerging from the center of the face and replacing the nose. Histopathological sections of the mass revealed evidence of nervous tissues composed of neurons and their supporting cells including microglia and astrocytes. Radiographs showed incomplete formation of frontal bones where the herniation of the mass occurred. These findings were consistent with a diagnosis of frontoethmoidal meningoencephalocele. Additionally, deformities of the 1st to the 3rd cervical vertebrae, the 3rd and lower thoracic vertebrae, and all lumbar vertebrae were found. Rib deformity was observed at both sides and rib fusion was presented on the right side. In conclusion, this study shows a rare case of a stillbirth puppy that possessed frontoethmoidal meningoencephalocele associated with multiple facial and skeletal abnormalities.