Taizo Hirohata

Type IV collagenase activity and cavernous sinus invasion in human pituitary adenomas

SummaryPituitary adenomas are regarded generally as benign tumours, but some of them can invade the cavernous sinus. On the other hand, matrix metalloproteinase-9 (MMP-9), which is a type IV collagenase, recently has been found to be expressed in matastases and to be related to the invasiveness of various malignant tumours including brain tumours. In order to investigate some characteristic features of pituitary adenomas which invade the cavernous sinus, we examined immunohistological studies for MMP-9 in seven pituitary adenomas for type IV collagen in a dura mater and assayed for type IV collagenase activity in seven adenomas using type IV collagen labelled with fluorescein isothiocyaniate (FITC).We found immunopositive adenoma cells for MMP-9 in all invasive adenoma and immunopositive spindle like cells for type IV collagen in the dura mater. All three invasive adenomas had high levels of type IV collagenase activity (0.57–0.72 U/ml), but the four adenomas which did not invade the cavernous sinus had low levels of type IV collagenase activity (0.0–0.10 U/ml).These results suggest that the level of type IV collagenase activity in a pituitary adenoma may be related to its ability to invade the cavernous sinus.

Analysis of the growth rate and cavernous sinus invasion of pituitary adenomas

SummaryPituitary adenomas generally are regarded as benign tumours, but a part of them can invade the cavernous sinus and recur. We examined 43 pituitary adenomas for the following factors: tumour volume, endocrinological function, cavernous sinus invasion, and growth rates examined by using anti-proliferating cell nuclear antigen (PCNA) and MIB1 (a novel anti-Ki-67) as markers.There was significant correlation between PCNA- and MIB1-positive cell rates and PCNA- and MIB1-positive cell rates were higher in the three cases with rapid regrowth than in the other cases. Staining was stronger and more distinct for MIB1 than for anti-PCNA; thus, MIB1-positive cells were easily distinguished by their intense immunoreactivity. MIB1 may be useful for detecting those rare cases with rapid regrowth even when initially regarded as benign tumours.Adenomas with cavernous sinus invasion were significantly larger than those demonstrating no invasion. However, no significant difference was found in the frequency of PCNA- or MIB1-positive cells between adenomas with and without cavernous sinus invasion.These findings suggest that cavernous sinus invasion and growth rate are independent biological factors. Therefore, cavernous sinus invasion may be due to chemical factors produced by the tumour itself rather than as a result of rapid tumour growth.

Endoscopic resection of intraventricular ependymal cyst presenting with psychosis

BACKGROUND Intracranial ependymal cysts are rare lesions generally located in the cerebral parenchyma, juxtraventricular region, or subarachnoid space; but no case of a purely intraventricular ependymal cyst has been reported. CASE REPORT A case of intraventricular ependymal cyst presenting with symptoms of psychosis is reported. The patients symptoms resolved almost completely following endoscopic resection of the cyst. The embryologic basis of the development of an ependymal cyst inside the ventricle and its histologic characteristics are discussed. Possible mechanism of psychosis in this case is also discussed. CONCLUSION Minimally invasive techniques, as in this case, may be useful in refractory psychotic cases with cystic lesions.