Relationships among DNA index, S-phase, and invasive behavior in anterior pituitary adenomas. A cytometric study of 61 cases with Feulgen-positive dna analysis

BACKGROUND Pituitary adenomas are usually well differentiated neoplasms, al though in about 1/3 of cases they invade the surrounding dura mater and bon e, as confirmed by surgical findings, resulting in a long-term possibility of relapse. METHODS To identify the cellular growth rate and to correlate it with surgi cal evidence of invasiveness, we performed the analysis of DNA with static cytometric quantitation on fresh surgical specimens, using a computer-assis ted image processor. The DNA index and the percentage of cells in S-phase ( %SPh) were obtained in 61 pituitary tumors consecutively operated on. In re lation to surgically verified infiltration of dura and bone, we identified 39 noninvasive and 22 invasive adenomas. The cavernous sinus (CS) was infil trated in 13 cases. On the basis of immunohistochernical staining and endoc rine activity we recognized 27 nonsecreting and 34 secreting adenomas. RESU LTS The DNA content was aneuploid in 33 cases (11 nonfunctioning, 22 functi oning; p = 0.05); there was no correlation with the invasive behavior of th e adenomas. The DNA index ranged between 0.93 and 2.50 (median 1.13); the r ange of %SPh was 0-12.00% (median 2.54%). In invasive adenomas the mean DNA index was 1.33 (p not significant) and the mean %SPh was 4.03% (p = 0.05). In CS-infiltrating pituitary adenomas, the mean DNA index was 1.44 (p = 0. 04) and the mean %SPh was 4.52% (p 0.05). CONCLUSIONS Our preliminary results seem to reveal a correlation between DN A index, %SPh, and invasive behavior of pituitary adenomas, encouraging the use of DNA analysis in the prognostic evaluation of these tumors. (C) 2001 by Elsevier Science Inc.