Fine-Needle Aspiration and Rapid on-Site Examination (ROSE)

Head and neck masses are clinical manifestations of a wide spectrum of differential diagnoses. The mass lesions may present cystic, solid, or solid-cystic. The underlying cause of the mass lesions can be benign (congenital/developmental or infections/inflammatory) or malignant (primary or secondary). Fine-needle aspiration is a well-accepted procedure to evaluate head and neck mass lesions. It is a minimally invasive, relatively tolerable, and cost-effective procedure. Fine-needle aspiration (FNA) does not leave any scar and can be repeated if additional diagnostic material is required. It can be performed in different clinical settings, and the diagnosis can be made rapidly. Rapid on-site evaluation (ROSE) is a process during FNA procedure that is performed by a cytologist or pathologist. A portion of the aspirated material is microscopically reviewed to assess specimen adequacy for diagnosis. ROSE can guide the FNA performer in changing the needle size or needle location. Moreover, the aspirated material can be triaged for ancillary studies such as flow cytometry, measurement of thyroglobulin level (TGB), parathyroid hormone (PTH) level or sending material for microbiology studies. In this chapter, ROSE, different clinical settings, and its utility are discussed.