Endocrine Abstracts

Introduction: During clinical observation the behaviour of pituitary tumours is often unpredictable. The work was aimed at evaluating Ki-67 and pituitary tumour transforming gene (PTTG) indices in pituitary adenomas.

Material and methods: The Ki-67 and PTTG indices were determined by immunochemistry in specimens excised from neurosurgically removed pituitary tumours. In fifty two examined patients (30 females and 22 males, mean age 50.5±15.4 years) who underwent pituitary tumour surgery, micro- and macroadenoma occurred in 10 and 42 cases respectively.

Results: The expression of Ki-67 and PTTG were revealed only in cells of pituitary tumours (absent in extra-tumoural tissue) and was present in 79 and 83% of adenomas respectively. The median values of Ki-67 and PTTG indices were 1.56% (IQR 3.05) and 1.02% (IQR 2.27) respectively. The index of PTTG, contrary to Ki-67 index, was significantly higher in adenomas with positive anterior pituitary hormone expression (n=40) as compared with adenomas with negative anterior pituitary hormone expression (n=12) (1.22 (IQR 2.17) vs 0.12 (IQR 1.07), P<0.05). Both Ki-67 and PTTG indices were not significantly related to tumour size category (microadenoma/macroadenoma) and were not correlated with tumour size. Contrary to Ki-67, PTTG index was significantly correlated with patient age (r=−0.267, P=0.026). We found no correlation of both above-mentioned indices with expression of pituitary hormones in examined specimens.

Conclusion: Expression of Ki-67 and PTTG was observed in the majority of pituitary adenomas. Ki-67 and PTTG expression, as determined in pituitary tumour specimens, was not related to the tumour size and kind of pituitary hormone expression.