[Controlled pathological study and preoperative MRI evaluation of the consistency of pituitary adenomas].

BACKGROUND & OBJECTIVE: Consistency of pituitary adenoma may influence surgical remote of the tumor. Preoperative evaluation of tumor consistency will be useful in guiding the operative approach. This study was designed to investigate the relationship among pituitary adenoma consistency, collagen type I and MRI signal intensity. METHODS: Twenty pituitary adenoma patients received transsphenoidal surgery. Preoperative MRI, H-E stains and collagen type I immunohistochemistry(IHC)-autonomic image analysis for tumor specimens were performed RESULTS: Ten tumors were soft, mean T2WI tumor/while matter signal intensity ratio (TWSIR) is 17.38%; six were moderate, mean T2WI TWSIR was 2.01; and 4 were firm, mean T2WI TWSIR was 1.56. Mean collagen type I positive area ratio(CIPAR) of soft, moderate, and firm tumors was 17.38%, 27.30%, and 40.31%, respectively. Both C1PAR and T2WI TWSIR were significantly different among three types (P < 0.01) C1PAR was negatively correlated to T2WI TWSIR(P < 0.01). CONCLUSION: Collagen type I content relates with the consistency of pituitary adenomas. MRI can predict of pituitary consistency adenoma; and those show hypointensity in T2WI are firm.

[Role of matrix metalloproteinases-9, 2 and their inhibitor-TIMP-1, 2 in invasive pituitary adenomas biological behavior].

BACKGROUND & OBJECTIVE: Usually pituitary adenomas are histological benign and grow slowly, but a proportion of them will become locally aggressive, and develop into invasive pituitary adenomas. The reasons for these differences in tumor behavior are poorly understood. Pituitary adenomas are abounding blood vessels. Angiogenesis and tumor invasion both require degradation of the extracellular matrix components to allow cell migration. The matrix metalloproteinases (MMPs) and their nature inhibitors-the tissue inhibitors of metalloproteinases (TIMPs) may play a central role in these processes. The aggressive mechanism of pituitary adenomas was studied through investigating the expression of MMP-9, MMP-2, TIMP-1, and TIMP-2 in both invasive and non-invasive adenomas. METHODS: Sixty-one surgical removed pituitary adenomas (forty-nine cases invasive and twelve non-invasive adenomas) were investigated. Immunohistochemistry staining (SP method) was used to detect the expression of MMP-9, MMP-2, TIMP-1, and TIMP-2 in two groups. The results were treated with semi-quantitative method and analyzed by using non-parameter rank sum test. RESULTS: Immunohistochemical staining of tumor cells for MMP-9, TIMP-1, MMP-2, and TIMP-2 were noted 95.9% (47/49), 57.1% (28/49), 75.5% (37/49) and 89.8% (44/49) in invasive adenomas, and 100% (12/12), 91.7% (11/12), 66.7% (8/12), and 91.7% (11/12) in non-invasive adenomas, respectively. Invasive tumors were significantly less expressing TIMP-1 and TIMP-2 (P < 0.05). There was no significant difference for MMP-9 or MMP-2 between invasive and non-invasive groups (P > 0.05). CONCLUSIONS: TIMP-1 and TIMP-2 may play a key role in invasive pituitary adenomas to biological behavior.