An oral choristoma in a foal resembling hairy polyp in humans.

The research article discusses a particular case where a newborn foal had a mass, resembling human hairy polyp, originating from its upper milk teeth, which contained a fully formed tooth.

Case Presentation

• The study elaborates on a neonatal foal that was observed with a significant growth protruding from its deciduous incisors. The mass was measured to be 6.5 cm and had a pedunculated shape, meaning it was attached to the body by a stalk or stem-like structure.
• The distal end, or the furthest area from the center of the body, of the mass was soft and covered by hair-bearing skin. Conversely, the proximal end, or the end of the mass closest to the center of the body, was firm, covered by mucosal epithelium (a type of tissue that lines various cavities in the body), and contained a fully grown tooth at the point of transection (the area where the growth was divided)

Microscopic Observations

• Under microscopic examination, the growth was found to be covered by the epidermis (the outermost layer of the skin) and mucosal epithelium.
• The bulk of the mass was composed of mature collagen, nonneoplastic fat and smooth muscle (muscle tissue that contracts involuntarily), and a singular tooth housed within a bony socket.

Diagnosis

• The mass was diagnosed as an oral choristoma, a term used to describe tumors composed of tissues not usually found in the area where they develop.
• The characteristics observed in this case were found to closely resemble those seen in human hairy polyps, which are also choristomas. Human hairy polyps, although benign, often contain various tissue types including hair follicles, hence the name.