CYTOMETRIC CHARACTERISTICS AND PROLIFERATION OF INVERTED PAPILLOMAS OF THE PARANASAL SINUSES

Inverted papillomas are rare tumors of unknown histologic origin occur ring in the nasal cavity and the paranasal sinuses. Specimens from 27 patients with histologically confirmed inverted papillomas were assess ed by DNA analysis and immunohistochemical identification of the proli ferating cell nuclear antigen (PCNA). One of the patients had squamous cell carcinoma associated with the inverted papilloma. According to t he 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 dev eloped recurrent disease. The recurrent papillomas from the patients i n the first group demonstrated the same low DNA indices as were observ ed in the primary tumors. The recurrences from the patients in the sec ond group occurred 1.5 and 2 years, respectively, following the primar y surgery. Although the primary tumors had high DNA indices, the recur rences demonstrated a further increase of the DNA indices with cytolog ical signs of malignancy. Quantitative DNA analysis and PCNA scoring o ffers a new, reliable means of assessing inverted papillomas and may p ossibly predict those tumors that behave more aggressively. Close foll ow up of patients presenting with high DNA indices and elevated PCNA s cores is recommended.