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MIB1 immunopositivity is associated with rapid regrowth of pituitary adenomas

SummaryPituitary adenomas are generally regarded as benign tumours, but they may recur. We identified eight patients with pituitary adenomas that showed rapid regrowth within 2 years of initial surgery. We estimated the percentage of cells in each specimen that showed positive immunostaining for MIB1 (a novel anti-Ki-67) and compared the values to those of 40 adenomas that showed no regrowth. The mean MIB1 index for 40 adenomas that showed no evidence of regrowth was 0.19±0.06%. This was significantly (p<0.0001) lower than that for adenomas that showed rapid regrowth (1.27±0.31%), based on the initial resected specimens. Immediately after detection of rapid regrowth and in adenomas that were resistant to bromocriptine or irradiation, the MIB1 index was always greater than 1.0%. Most patients with rapidly regrowing adenomas were well controlled by radiation therapy.Our results suggest that a MIB1 index greater than 1.0% may be a useful predictor of rapid regrowth of pituitary adenomas and may be useful for planning of therapy.

Concomitant pituitary adenoma and Rathke's cleft cyst.

Abstract We reviewed the clinical, radiological and surgical findings in patients with both pituitary adenoma and Rathkes cleft cyst. We retrospectively selected patients with both lesions from the 374 patients in whom a sellar/juxtasellar lesion was detected on MRI at 1.5 tesla. All patients received intravenous contrast medium. Concomitant pituitary adenoma and Rathkes cleft cyst were found in eight patients (2.1 %). The frequency of the combination was 3.5 % of pituitary adenomas and 11 % of Rathkes cleft cysts. Symptoms were always due to the adenoma, secreting adrenocorticotrophin in two patients and growth hormone in six. The adenoma was larger in five patients, and the cyst in three. The cysts gave variable signal. The adenoma was adjacent to the cyst in seven patients, and enclosed it in the other patient. As a result of experience with MRI, concomitant pituitary adenoma and Rathkes cleft cyst are now known not to be as rare as thought previously. When a nonenhancing cyst-like structure is demonstrated in a patient with pituitary adenoma, the possibility of a coexisting Rathkes cleft cyst should be considered.

Secretion of Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 by Meningiomas Detected by Cell Immunoblot Analysis

Summary To identify features of meningiomas that infiltrate dura mater, and to examine the role Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) secretion in meningiomas, a cell immunoblot assay study was performed in 20 meningiomas. MMP-9 secretion was detected in 20 (100%) meningiomas and was independent of histological features. TIMP-1 secretion was detected in 8 (40%) meningiomas. For a cell immunoblot volume which included approximately 1350 cells, there were 50.4±49.4 dots which showed immunoreactivity to MMP-9 and 2.0±4.2 which showed immunoreactivity to TIMP-1. The number of dots that showed immunoreactivity to MMP-9 was not significantly different between tumours with atypical and benign histological features. TIMP-1 secretion was found in only 8 (40%) specimens and the percentage of TIMP-1 secreting cells was significantly lower than that of MMP-9 secretion. Thus, we propose that meningiomas classified histologically as both atypical and benign have the potential to infiltrate dura mater.

Intrasellar Rhabdomyosarcoma: Case Report

OBJECTIVE AND IMPORTANCE There has been only one reported case of an intrasellar rhabdomyosarcoma, the origin of which was in the paranasal sinus. The authors encountered a patient with an intrasellar rhabdomyosarcoma with no evidence of tumor at any additional sites. CLINICAL PRESENTATION A 28-year-old otherwise healthy man complaining of headache exhibited left abducent nerve palsy and left visual disturbance. The patient was diagnosed as having a sellar tumor invading the left cavernous sinus. INTERVENTIONNear total removal of the tumor was achieved via a transsphenoidal approach. Histologically, the tumor was composed of small, round-to-elongated undifferentiated cells and large spindle cells with myoblastic features. Immunohistochemically, tumor cells were positive for antibodies against desmin, myoglobin, and &agr;-smooth muscle actin. The tumor was identified as an embryonal rhabdomyosarcoma on the basis of the above pathological findings. Systemic investigation, including the nasal and paranasal regions, failed to detect any additional tumors. Postoperative local radiation therapy and chemotherapy with the use of ifosfamide, etoposide, and vincristine brought about complete initial remission. CONCLUSIONRhabdomyosarcoma should be considered in the differential diagnosis of a primary intrasellar neoplasm.

Transsphenoidal “Cross Court” Approach Using a Slightly Modified Speculum to Reach Pituitary Adenomas with Lateral Growth

Summary¶ Background. The purpose of this study was to evaluate the usefulness of an oblique “cross court” transsphenoidal approach using a speculum with slightly modified projections for pituitary adenomas showing lateral extension. Method. The projection of the speculum on the side of the cavernous lesion was shortened by 5 mm. The tip of the longer projection was placed in the sphenoid sinus, while the end of the shorter projection was placed on the concha sphenoidalis. An oblique transsphenoidal view was then easily obtained by opening the speculum. The contralateral nasal incisura had to be widened in some cases to achieve a more oblique view. Findings. Twenty-eight patients diagnosed with pituitary adenoma showing lateral growth underwent adenomectomy under direct observation of the medial portion of the cavernous sinus using this approach. Postoperative normalization of hyperendocrinopathy or gross total removal of the tumour was achieved in the majority of patients. Interpretation. An oblique transsphenoidal approach using this speculum and contralateral minor maxillary osteotomy afforded a direct view of the medial cavernous sinus, sufficient for the removal of adenomas showing minor to moderate lateral growth.

A case of non-functioning pituitary adenoma accompanied by a large cyst

Cystic transformation of pituitary adenomas is not infrequently seen [3] and is probably due to haemolysis or necrosis of the tumour following pituitary apoplexy [2]. In such cases, the cyst is usually seen within the tumour substance and is moderate in size [1, 3, 4]. Formation of a large cyst adjacent to the tumour is extremely rare [5]. We present a case of rapid formation of a large cyst in the frontal lobe following surgery on a non-functioning pituitary adenoma.