Heterotopic neural tissue in the pharynx of a 7-week-old kitten.

A 7-week-old male kitten had a pharyngeal mass (1 x 2 cm) causing displacement of the tongue. The surgically resected tissue was seen to be a moderately discrete subepithelial mass comprising islands of neuroglia and neurons separated by dense collagenous connective tissue. It is not known whether this mass retained any connection with the brain. Histochemical and immunohistochemical examination confirmed the presence of neurons and a pleocellular glial population, supporting a diagnosis of heterotopic neural tissue. The cat remained well 20 months after surgical treatment. Heterotopic neural tissue is well-recognized in man but has not been described in animals.