Abstract
Assessment of mitotic activity represents one of the oldest and most routinely used histopathologic methods of evaluating the biological aggressiveness of human tumors. In the case of pituitary tumors, however, the relevance of this approach as a means of gaging tumor behavior remains ill-defined. In this article, the relationship between the mitotic index and biological aggressiveness of pituitary tumors was evaluated in a series of 54 pituitary adenomas and 6 primary pituitary carcinomas. All tumors were fully classified by immunohistochemistry and electron microscopy; adenomas were further stratified on the basis of their invasion status, the latter being defined as gross, operatively, or radiologically apparent infiltration of dura or bone. Mitotic figures were present in 11 tumors, 10 being either invasive adenomas or pituitary carcinomas. A significant association between the presence of mitotic figures and tumor behavior was noted, as evidenced by progressive increments in the proportion of cases expressing mitotic figures in the categories of noninvasive adenoma, invasive adenoma, and pituitary carcinoma (3.9, 21.4, and 66.7%, respectively; Fisher’s exact test, two-tailed,p<0.001). The mitotic index, however, appeared to be a less informative parameter, being extremely low in all cases (mean=0.016%±0.005 [±SEM]). Although the mean mitotic index in pituitary carcinomas (0.09%±0.035) was significantly higher than the mean mitotic index of either noninvasive adenomas (0.002%±0.002) or invasive adenomas (0.013%±0.005), no practical threshold value capable of distinguishing these three groups was evident. Comparison of the mitotic index with Ki-67 derived growth fractions in these tumors revealed a significant but weak linear correlation (r=0.41,p<0.01). These data suggest that when, mitotic figures are present, they do provide some indication of the behavior and invasive potential of pituitary tumors. For routine diagnostic purposes, however, the discriminating power of this parameter is somewhat limited, being superseded by alternative and more informative methods of growth fraction determination such as that provided by the Ki-67 immunolabeling.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Clayton F, Hopkins C. Pathologic correlates of prognosis in lymph node positive breast carcinomas. Cancer 71:1780–1790, 1993.
Clayton F. Pathologic correlates of survival in 378 lymph node-negative infiltrating ductal carcinomas. Mitotic count is the best single indicator. Cancer 68:1309–1317, 1991.
van Diest P, Baak J. The morphometric prognostic index is the strongest prognosticator in premenopausal lymph node-negative and lymph node positive breast cancer patients. Hum Pathol 22:326–330, 1991.
Wilson C. Role of surgery in the management of pituitary tumors. Neurosurg Clin N Am 1:139–159, 1990.
Wilson C. A decade of pituitary microsurgery: the Herbert Olivecrona lecture. J Neurosurg 61:814–833, 1984.
Selman WR, Laws ERJ, Scheithauer BW, Carpenter SM. The occurrence of dural invasion in pituitary adenomas. J Neurosurg 64:402–407, 1984.
Scheithauer B, Kovacs K, Laws EJ, Randall R. Pathology of invasive pituitary tumors with special reference to functional classification. J Neurosurg 65:733–744, 1986.
Randall RV, Laws ER Jr, Abboud CF, Ebersold MJ, Kao PC, Scheithauer BW. Transsphenoidal microsurgical treatment of prolactin-producing pituitary adenomas: results in 100 patients. Mayo Clin Proc 58:108–121, 1983.
Laws ER Jr, Scheithauer B, Carpenter S, Randall R, Abboud C. The pathogenesis of acromegaly: clinical and immunocytochemical analysis in 75 patients. J Neurosurg 63:35–38, 1984.
Laws E, Thapar K. Surgical management of pituitary tumors. Ballière’s Clin Endocrinol Metab 9(2):391–406, 1995.
Thapar K, Kovacs K, Scheithauer BW, Stefaneanu L, Horvath E, Pernicone PJ, Murray D, Laws ER Jr. Proliferative activity and invasiveness among pituitary adenomas and carcinomas: an analysis using the MIB-1 antibody. Neurosurgery 38(1):99–107, 1996.
Taylor CR, Shan-Rong S, Chaiwun B, Young L, Imam SA, Cote RJ. Strategies for improving the immunohistochemical staining of various intranuclear prognostic markers in formalin-paraffin sections: androgen receptor, estrogen receptor, progesterone receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen revealed by antigen retrieval techniques. Hum Pathol 25:263–270, 1994.
Hsu SM, Raine L, Fanger H. The use of antiavidin antibody and avidin-biotin peroxidase complex in immunoperoxidase technics. Am J Clin Pathol 75:816–821, 1981.
Kramer A, Saeger W, Tallen G, Ludecke D. DNA measurement, proliferation markers, and other factors in pituitary adenomas. Endocr Pathol 5:198–211, 1994.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Thapar, K., Yamada, Y., Scheithauer, B. et al. Assessment of mitotic activity in pituitary adenomas and carcinomas. Endocr Pathol 7, 215–221 (1996). https://doi.org/10.1007/BF02739924
Issue Date:
DOI: https://doi.org/10.1007/BF02739924