The cytotechnologist and cytopathologist examine cells exfoliated or aspirated from various sites. Cells can be aspirated by a pathologist or clinician from palpable lesions, such as those in the thyroid, breast, and soft tissue or aspirated under CT, ultrasound, or fluoroscopic guidance by a radiologist for non-palpable lesions. These cytologic samples may be used for screening purposes (Pap smears), definitive diagnosis (FNA), or a combination thereof (bronchial washings, FNA).

A cytotechnologist screens cytology specimens, by reviewing morphologic features of the cells, relating these findings to the patient's clinical history, and rendering a cytologic impression. The pathologist reviews abnormal Pap smears and all non-gynecologic cases and issues a final report. The cytologic diagnosis is used to diagnose primary or metastatic tumors or infectious and reactive conditions, to select patients who need further evaluation, and to provide a means to follow the success of cancer therapy.