Correlation of Treatment Outcome, Histologic Type, and PCNA Labelling Index in Craniopharyngiomas

Kim, Ki Jeong; Oh, Chang Wan; Cho, Byung Kyu; Kim, Jung Sun; Chi, Je Geun; Choi, Kil Soo

Abstract

Craniopharyngiomas exhibit benign histologic features. However, such tumors have a relatively high incidence of recurrence after surgical removal, In order to device reliable and efficient methods in identifying craniopharyngiomas with increased risk for recurrence after surgical removal, proliferating cell nuclear antigen(PCNA) expressions as well as histological characteristics of the tumor were analyzed. There were 43 patients who had been surgically confirmed and had paraffin-embedded tissue from June, 1984 to May, 1993 available for analysis from our department. Of the 43 patients, eighteen cases were in children(age of 15 years of less) and 25 cases were in adults. The mean follow-up period was 42.7 months. The histologic types were adamantinomatous in 30 cases, squamous papillary in 9 cases and mixed in 4 cases. There was no case of tumor recurrence in the squamous papillary group, while the recurrence rate was about 55% in the adamantinous group after surgical removal alone. The mean age of the admantinous group was younger than that of the squamous papillary group(17.5 vs. 37.9 years old. p=0.0012), and the squamous papillary type was found only in adults(age over 20). In the group of 30 patients treated by surgical removal without radiation, the PCNA labelling index, calculated by counting the basal cell layer only, was significantly higher in the group with recurrence than without recurrence(9.51 vs. 6.58. p=0.001). However, the PCNA labelling index obtained by counting all cells in the four high-power(x400) fields failed to demonstrate any correlation with tumor recurrence. With a reference value of 8, PCNA index of the basal cell layer demonstrated the predictive sensitivity of 81.8% and specificity of 84.2% for tumor recurrence. There was no significant difference in PCNA labelling indices between adamantinous and squamous papillary types. As PCNA labelling index of the basal cell layer, as well as the histologic type, are sensitive indicators for prediction of tumor recurrence after surgical removal of craniopharyngiomas, therefore they should be considered as an index for biologic behavior of the tumor.