A case of intracerebral schwannoma (ICS) occurring in a 33-year-old woman is presented. The patient's history of headache, numbness, tingling and the recent development of weakness of the right upper extremity with right facial droop began during pregnancy. Magnetic resonance imaging (MRI) showed a 4 x 2 x 2 cm heterogeneous, gadolinium-enhanced mass at the left frontoparietal junction, with peritumoral edema and a dural-based attachment. During her pregnancy, the mass increased in size. The surgically resected specimen consisted of lobulated, somewhat gelatinous soft tissue. Microscopically, the tumor demonstrated classic biphasic Antoni type A and B patterns, admixed with degenerative changes. Immunohistochemically, the neoplastic cells were positive for S-100 protein (diffuse and strong), CD34 (primarily in Antoni B areas), glial fibrillary acidic protein (GFAP; weak and diffuse) and calretinin (mainly in Antoni A areas), while none was positive for CD31, estrogen and progesterone receptors, bcl-2, or epithelial membrane antigen (EMA). Ultrastructurally, basal laminae and Luse bodies were identified. The differential diagnosis includes fibrous meningioma, solitary fibrous tumor, and ICS. Twenty-seven cases of ICS were reviewed in which the histological diagnosis was confirmed immunohistochemically or ultrastructually, and the cases were summarized (including the present case). A combined use of immunostains (S-100 protein, EMA, CD34, and maybe calretinin) is of great help in distinguishing ICS from its histological mimickers.

Meningiomas are well known to be responsive to estrogen/progesterone stimulation, and their expression of estrogen/progesterone receptor (ER/PR) has been documented. On the other hand, there are several reports studying expression of apoptosis-regulating proteins (ARPs) and its significance in meningiomas. However, very limited published information exists on the exact relation among sex hormone receptor status, apoptosis, proliferation index (PI), and histological grade in meningiomas. A total of 57 cases of non-malignant meningiomas were selected, and histologically reviewed and graded (WHO grades 1, 2). All these cases were immunostained for ER, PR, Ki-67, and ARPs including bax, bcl-2, and bcl-xL. Sections were graded semiquantitatively for intensity and extent of immunostaining. PI was expressed as a percentage of Ki-67 positive tumor cells. Expression of bax, bcl-2, bcl-xL, ER, and PR was seen in 100, 35.1, 24.6, 10.4, and 87.2% of cases, respectively. Bax was expressed diffusely and strongly, while Bcl-2 tended to be expressed weakly and focally. Bcl-xL appeared to be expressed relatively strongly and diffusely in a small subset. There was significantly higher PI as well as expression of PR in grade 1 group than in grade 2 group. A weak negative correlation was observed between Bcl-2 and PR (r =-0.472, P < 0.0014). Given high-level expression of pro-apoptotic bax, which seems to be constitutionally expressed, in contrast to low-level expression of antiapoptotic bcl-2 and bcl-xL, other antiapoptotic proteins may involve the proliferation of meningiomas. A significant negative relation exists between PR and Bcl-2 in meningiomas, which might have some biological and clinical significance.

A tissue microarray (TMA) was constructed using 47 neurodegenerative diseases (NDD), including Alzheimer's disease (AD; n = 30) and non-AD NDD (n = 17), and from seven controls. For validation of the methodology, the following three immunostains were used. Tau and beta-amyloid-related pathologies were more significantly recognized in tauopathies/AD compared to non-tauopathies/controls, and these results were comparable to the assessment of the whole brain sections. But no alpha-synuclein pathologies were observed despite five cases of dementia with Lewy bodies. It was concluded that the TMA technique is useful for NDD with diffuse pathological processes but not for those with patchy and occasional lesions or in early stages. Growth-associated protein (GAP)-43 and calretinin were also immunostained. A significant reduction in GAP-43 expression was seen in the frontal lobe and hippocampus in AD compared to non-AD cases, but not in other areas. No significant difference in number of anticalretinin immunoreactive neurons or in density of immunoreactive neurites was observed between any of the NDD and controls, which may indicate that calretinin-positive neurons are spared in the degenerative process. These results are compatible with the previous studies. These analyses were performed rapidly in a large number of cases using a single slide under uniform staining conditions.

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