Thymoma in a Java sparrow (Padda oryzivora).

Thymoma is described in a 3-year-old female Java sparrow (Padda oryzivora). Histopathologically, the subcutaneous mass from the cervical region consisted of epithelial cells characterized by large polyhedral cells and spindle cells, which sometimes showed squamous differentiation, and small lymphocytes without apparent atypical forms. Immunohistochemically, the epithelial cells possessed cytokeratin in their cytoplasm and proliferating cell nuclear antigen.