Cytology of canine and feline cutaneous and subcutaneous lesions and lymph nodes.

Fine-needle aspirates and impression smears of cutaneous and subcutaneous lesions and lymph nodes are the most commonly submitted cytology samples from veterinary patients. Diagnostic cytology samples of these lesions are easily collected in patients without anesthesia or analgesia. Cytology can yield immediate results and may prevent the need for additional tests that use more invasive methods of sample collection. This article offers a brief review of how to collect and submit cytology samples and describes cytologic lesions that often are diagnosed in dogs and cats. When applicable, differences between disease progression in dogs and cats are described.