| Objective: To study the MRI characteristics of invasive pituitary adenomas; To assess the role of the changes of ICA in diagnosing invasiveness of pituitary adenomas; To evaluate the value of SIPAP classification in describing the imaging of pituitary adenomas; To investigate the correlations of hormone types, expression of Ki-67 and MMP-9 with the invasiveness of pituitary adenomas.Part one: The study of MRI characteristics in invasive pituitary adenomasMaterials and Methods: 90 patients with pituitary adenomas (40 male patients and 50 female patients; mean age, 44.0±15.7 yr) that were confirmed by operation and pathology and 150 patients without sellar diseases were enrolled. MRI sequences included: TI weighted sagital, coronal and axial scans (TR 600ms TE 20ms) before and after contrast administration; T2 weighted coronal scans (TR 4000ms TE 80ms). Contrast administration was obtained by intravenous Gd-DTPA (0.1mmol/kg) .Tumor size (height, width, thickness, maximum dimension and volume), contour, signal intensity and contrast enhancement were studied. The correlation of these features with invasiveness of pituitary adenomas was assessed. SIPAP classification was used to describe tumor extensions. Distance between cavernous carotid arteries, the percentage of intracavernous ICA encased by the adenomas, and the relationship between tumor and the intercarotid lines joining the intracavernous and supracavernous portions of the ICA were observed and the correlation of these features with invasiveness was assessed.Results: There were 59 cases of IPAs (29 male patients and 30 femalepatients) that were confirmed by operation in our study. The volume and the maximum diameter of pituitary adenomas were related to invasiveness. Lobular contour of invasive adenomas was significant different from that of noninvasive adenomas. Most of the signal intensity of invasive pituitary adenomas was isointensity on both T1WI (71.2%) and T2WI (50.8%). Heterogeneous intensity of invasive pituitary adenomas was not more than that of noninvasive pituitary adenomas. The contrast enhancement of invasive pituitary adenomas was slight (30.5%) to moderate (49.2%), and 25 cases (42.4%) enhanced heterogeneously. No significant correlation was found between invasiveness and the presence or absence of suprasellar extension except that hydrocephalus can only be seen in invasive pituitary adenomas. The presence of local bulging of the floor of the sella was a helpful sign of floor invasion(SPE 90%, PPV 91%).The mean distance between the medial walls of the intracavernous portions of the ICA of the patients without sellar diseases and with pituitary adenomas were 1.70cm?.35cm and 2.44cm+ 0.42cm respectively. Although extension beyond the medial intercarotid line was observed in all invasive pituitary adenomas, it was not helpful for the diagnosis of cavernous sinus invasion (SPE 30%, PPV 42%). Crossing of lateral intercarotid line was a good sign of cavernous invasion (PPV 85%, NPV 97%). When 2/3 or more of the perimeter of the intracavernous ICA was encased by adenomas, the cavernous sinus was always invaded (PPV 100%, NPV 84%). The medial wall of the cavernous sinus was not depicted in all invasive pituitary adenomas, and could be seen in only 34 noninvasive pituitary adenomas. Bulging of the lateral wall of the cavernous sinus was more frequent in invasive adenomas.Part two: The correlation between invasiveness of pituitary adenomas and expression of Ki-67 and MMP-9Materials and Methods: Tumor specimens were obtained from 90 patientswith pituitary adenomas. Specimens were fixed in 10% buffered formalin and then embedded in paraffin. The expression of Ki-67 antigen and MMP-9 were assessed by immuno-histochemial staining (SP method).Results: The mean Ki-67 LI for noninvasive adenomas and invasive adenomas were 1.07%±1.12%(range0.01%-3.90%) and 2.45%±2.5l%(range 0.01%-14.22%) respectively. Ki-67 LI of 11 cases with recurrent tumors was higher than that of primary pituitary adenomas. The mean Ki-67 LI i... |
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