Multiple adenomas of the thyroid gland in an African green monkey (Chlorocebus aethiops)

Two cystadenomas and one solid adenoma of the thyroid gland in a 27-year-old female African green monkey (Chlorocebus aethiops) are described here. Histologically, the solid adenoma was classified as a well-defined solid follicular adenoma of microfollicular type. The solid adenoma was positive for thyroglobulin in immunohistochemistry staining, whereas the cystadenomas stained positive for both thyroglobulin and calcitonin. No evidence of excess hormone production related to the tumor presence was detected.