Cytometric Characteristics and Proliferation of Inverted Papillomas of the Paranasal Sinuses

Inverted papillomas are rare tumors of unknown histologic origin occurring in the nasal cavity and the paranasal sinuses. Specimens from 27 patients with histologically confirmed inverted papillomas were assessed by DNA analysis and immunohistochemical identification of the proliferating cell nuclear antigen (PCNA). One of the patients had squamous cell carcinoma associated with the inverted papilloma. According to the results of DNA analysis, patients with inverted papillomas would be divided into two groups. One group demonstrated low DNA indices and a low PCNA score. The second group showed higher DNA values associated with an increased proliferation rate. Two patients from each group developed recurrent disease. The recurrent papillomas from the patients in the first group demonstrated the same low DNA indices as were observed in the primary tumors. The recurrences from the patients in the second group occurred 1.5 and 2 years, respectively, following the primary surgery. Although the primary tumors had high DNA indices, the recurrences demonstrated a further increase of the DNA indices with cytological signs of malignancy. Quantitative DNA analysis and PCNA scoring offers a new, reliable means of assessing inverted papillomas and may possibly predict those tumors that behave more aggressively. Close follow up of patients presenting with high DNA indices and elevated PCNA scores is recommended.