"History of Respiratory Cytopathology Application of the cytologic method to specifically examine respiratory specimens was used first in Europe by the mid-1800s, though exfoliated epithelial cells were described as early as the 18th century. Hampeln's 1897 paper is credited with the first thorough description of normal and non- malignant cellular elements seen in sputum. And, about two decades later his was one of the first publications to document the use of sputum cytology to diagnose pulmonary carcinoma in a series of 25 cases rather than a single report. Only sporadic and limited publications of respiratory cytology occurred in the early decades of the 20th century. A 3-year study of sputum cytology that culminated in a 1944 publication is considered as one of the most important contributions to clinical cytology of chest diseases in the first half of the 20th century"--Provided by publisher.