First Report of Immunohistochemically Confirmed Pleomorphic Rhabdomyosarcoma in a Cockatiel (Nymphicus hollandicus) in Iran

Sarcomas are malignant neoplasms arising from mesenchymal tissues, including bone, muscle, fat, and connective tissues. Rhabdomyosarcoma (RMS) is an aggressive form that originates from skeletal muscle cells. The present study a case of RMS in a cockatiel (Nymphicus hollandicus). The tumor was characterized by its rapid growth and significant clinical signs, which included the development of a hard mass in the bird’s head region. Radiographic examination revealed a well-defined and dense structure, and fine-needle aspiration (FNA) provided preliminary evidence of a sarcomatous lesion. Surgical removal was performed to alleviate discomfort and confirm the diagnosis through histopathological and immunohistochemical examination. The neoplastic cells exhibited pleomorphism with an orientated, spiral growth pattern and prominent nucleoli. Based on our findings, pleomorphic RMS was confirmed. Fortunately, the bird is still alive two months post-surgery, with no signs of tumor recurrence. Rapid growth and tendency to spread to other parts highlight the aggressive nature of this tumor and the necessity for prompt and accurate diagnosis. Continued research and collaboration in the study of avian tumors are essential for advancing our understanding and improving clinical outcomes for affected birds.