Category IV: Neoplastic: Benign

Abstract

The Papanicolaou Society of Cytopathology recommendations for respiratory cytology utilize a neoplastic category that contains both clearly benign neoplasms and neoplasms with a low but undetermined malignant potential. Assignment to the neoplastic category requires that sufficient morphologic features are present to definitively define a smear as representative of a specific benign neoplasm. Neoplasms with low malignant potential and some low-grade carcinomas overlap morphologically and are cytologically difficult to separate. Clearly malignant neoplasms including a variety of well-differentiated adenocarcinomas and low-grade sarcomas morphologically overlap entities with low malignant potential. Thus, separation of the neoplastic category into two subcategories has importance for cytologic evaluation, differential diagnosis, and assessment of malignancy risk. This subdivision of the neoplastic category into those lesions which are clearly benign and those that have a low risk for recurrence or metastasis is clinically useful. This categorization allows the treating physician discretion in his or her therapeutic approach to a patient. Lesions of low or undetermined malignant risk in a young, healthy individual are often resected, while a similar neoplasm in an elderly infirm individual may receive only observational or medical therapy.