Cytology is the microscopic examination of cell samples. Cytology can be used to diagnose growths or masses found on the surface of the body, and also to assess bodily fluids, internal organs, and abnormal fluids that may accumulate, especially in the chest and abdomen. Cells can be collected using various methods including fine needle aspiration, skin scraping, impression smear, cotton-tipped swabs, or lavage. A biopsy is the surgical removal of a representative sample of tissue from a suspicious lesion. The most common biopsy techniques are punch biopsy, wedge biopsy, and excision biopsy. The tissue is then processed and is examined under a microscope via histopathology. Histopathology allows the veterinary pathologist to make a diagnosis, classify the tumor, and predict the course of the disease.
Xanthomas are discrete masses or diffuse, thickened areas of skin that are yellow-orange and dimpled in appearance. They are accumulations of fat and cholesterol and are most commonly found in cockatiels and budgies (and they are more often found in females).