Tubular duplication of the cervical portion of the esophagus in a foal.

This research discusses a case of esophageal duplication in a newborn female Quarter Horse, which presented as a noticeable mass after feeding. Surgical intervention was successful in fully removing this mass, confirmed through histological examinations to be a rare occurrence of tubular duplication of the esophagus in horses.

Case Background

• The subject of the study was a 10-day-old female Quarter Horse that had developed a significant size mass at the back of its jawline after feeding.
• Additionally, the foal was experiencing difficulties in breathing when lying on its side, a condition known as dyspneic when in lateral recumbency.

Diagnostic Procedures

• Diagnostic procedures used in examining this case included radiography and ultrasonography. These procedures showed the mass to be filled with fluid and gas.
• An endoscopy further revealed an unremarkable upper airway and esophagus, suggesting the issue originated at a specific localized area.

Surgical Intervention

• Complete surgical resection, which involves the removal of the mass, was performed on the foal and was successful. The mass had a 3-mm diameter communication with the esophageal surface at the pharyngoesophageal oriface, or the junction between the pharynx and the esophagus.

Post-operative Analysis

• Post-operative histologic examination (microscopic examination of tissue in order to study the manifestations of disease) of the mass was conducted, revealing stratified squamous epithelium lining the cavity resembling a cyst.
• The mass wall contained smooth muscle layers, both longitudinal and circumferential, with few submucosal glands. These structures are inherent to the native tissue of the esophagus, hinting the mass was a part of the esophagus which had grown atypically.
• The clinical, gross pathologic (the study of the structural and functional changes in tissues and organs of the body which cause or are caused by disease), and histopathologic findings were consistent with tubular duplication of the cervical portion of the esophagus. This is a rare congenital condition where a portion of the esophagus develops into an additional tube or tubular structure.