Yoshinori Takekawa

Pathological and immunohistochemical findings of an autopsy case of adult moyamoya disease.

Moyamoya disease is vaso‐occlusive disease involving the arteries of the circle of Willis that is accompanied by a compensatory recruitment of a vascular network. The pathological and immunohistochemical findings of an autopsy case of hemorrhagic moyamoya disease in a 69‐year‐old woman are described in the present report. The autopsy findings of the brain revealed cerebral and intraventricular hemorrhage with edema. The left anterior cerebral artery, bilateral middle cerebral arteries and left posterior cerebral artery were marked narrowing, and the other arteries revealed mild narrowing. Microscopically, the arteries of the circle of Willis showed narrowed lumen, fibrocellular intimal thickening, marked tortuousness of internal elastic lamina and attenuation of media. The thickened intima was composed of smooth muscle cells. The vessels with dilated or irregular‐shaped lumen suggested abnormal vascular networks demonstrated by angiography. In this case, no correlation between the abnormal vascular network and expression of VEGF or VEGF receptor was disclosed. It was hypothesized that abnormal vascular networks might be composed of collateral vessels in relation to various pathological changes of the arteries, such as occlusion and stenosis, and intracranial hemorrhage in patients with moyamoya disease might occur as a result of rupture of arteries including abnormal vascular networks.

Expression of the multidrug-resistance P-glycoprotein (Pgp, MDR-1) by endothelial cells of the neovasculature in central nervous system tumors

To elucidate the expression of theMDR1 gene products P-glycoprotein (Pgp) in endothelial cells on newly formed blood microvessels in brain tumors, 30 brain tumors were examined by immunohistochemistry using an anti-Pgp monoclonal antibody, JSB-1. Positive reactions for JSB-1 were detected in endothelial cells in newly formed microvessels in all 16 cases of glioma but not in the 4 meningiomas. Although endothelial cells in newly formed microvessels of all 10 metastatic carcinomas showed positive reactions, negative reactions were seen in those of the primary carcinomas. Compared with reactions of the endothelial cells of normal cerebral capillaries, weak reactions were found in the endothelial cells forming glomeruloid proliferation in newly formed microvessels in the eight glioblastomas and at the border of the surrounding cerebral tissue of the metastatic carcinomas. Since the endothelial cells showing glomeruloid proliferation also had a high proliferative cell nuclear antigen labeling index, the present findings demonstrate a negative relationship between positive reactions for Pgp and the proliferative activities of endothelial cells in cerebral capillaries.

Expression of apoptosis and its related protein in astrocytic tumors

The relationship between malignant potential and apoptosis in astrocytic tumors has not been clearly defined, and further classification of astrocytic tumors is necessary. To elucidate the relationship between the histopathological grade of astrocytic tumors and apoptosis, we studied 25 cases of astrocytic tumors, comprising 10 cases of glioblastoma (GB), 7 cases of anaplastic astrocytoma (AA), and 8 cases of astrocytoma (AC). We detected apoptosis using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. We studied immunohistochemical expression of bcl-2 protein and p53 protein, which are apoptosis-related factors, and cell proliferative activity using Ki-67 antibody. No significant change was noted between apoptotic index and the histological grade of the tumors. In GB, apoptotic cell-rich foci were present at the pseudopalisading necrosis. No correlation between histopathological grades and expression of either p53 or bcl-2 was observed. In GB, however, poor distribution of bcl-2 was found in the areas of pseudopalisade formation. bcl-2 is one of the regulatory factors in the cell cycle and inhibits apoptosis. Expression of apoptosis had no correlation with histopathological grade. However, in GB, the distribution of apoptotic cells showed a correlation with bcl-2-poor foci. It was thought that apoptosis was one of the regulatory factors in the formation of pseudopalisading necrosis in GB.

Vascular endothelial growth factor and neovascularization in astrocytic tumors

It has been widely recognized that the vascular structure is an important factor when making a histopathological diagnosis and assessing the malignancy potential, especially of astrocytic tumors. The vascular endothelial growth factor (VEGF), which is thought to be regulated by the p53 gene, is a regulation factor for tumor neovascularization. The relationship between VEGF distribution and neovasculature was studied in 42 cases of astrocytic tumors (grades 1–4), which were obtained from surgical material, and the St Anne‐Mayo grading system was applied. The relationship between the labeling indices (LI) of VEGF and LI of p53 protein in tumor cells was also studied using immunohistochemistry. The VEGF LI in high‐grade malignancy potential tumors, such as grade 3 and grade 4 tumors, was significantly higher than those that were low grade. In grade 4 tumors, a significant correlation between the VEGF LI and the proliferation indices of endothelial cells of neovasculatures was observed. No significant correlation was noted between p53 LI and VEGF LI, as well as p53 LI and histopathological grade. In astrocytic tumors, expression of VEGF may be correlated to tumor neovascularization, and can be considered as an indicator of malignancy potential in astrocytic tumors.

Cytologic Findings of Epithelioid Trophoblastic Tumor of the Uterus

BACKGROUND Epithelioid trophoblastic tumor (ETT) is a rare entity within trophoblastic tumors. It is difficult to recognize ETT because of its epithelioid appearance. CASE A 35-year-old female, 5 years after pregnancy, experienced genital bleeding 2 months prior to consulting us. Preoperative laboratory data showed a slightly elevated serum level of human chorionic gonadotropin (hCG). A cytologic cervical smear revealed large, polygonal, atypical cells. These cells had mononucleate, ovoid, irregularly enlarged and hyperchromatic nuclei with 1 or 2 conspicuous nucleoli. The cytoplasm was thin and abundant, with a distinct cell membrane, and sometimes showed vacuolation. The patient was diagnosed with uterine cancer, and hysterectomy was performed. The tumor was present in the uterine corpus, measuring 3 x 2.5 x 2.5 cm. Histologically, it was composed of mainly mononuclear tumor cell nests resembling intermediate trophoblastic cells with zones of hyaline material. Immunohistochemically, the tumor was positive for cytokeratin and placental alkaline phosphatase but negative for hCG and human placental lactogen. The tumor was subsequently diagnosed as ETT. CONCLUSION It was difficult to make a definitive diagnosis of ETT using only a cytologic specimen. The diagnosis of ETT is facilitated by a combination of cytologic, histopathologic and clinical findings.

Pathologic, cytologic and immunohistochemical findings of an intra-abdominal desmoplastic small round cell tumor in a 15-year-old male.

The intra‐abdominal desmoplastic small round cell tumor is a rare neoplasm. It usually occurs in young males and diffusely involves the peritoneum and pursues an aggressive clinical course. The present patient was a 15‐year‐old male who experienced abdominal pain and abdominal swelling. The patient was diagnosed with an intestinal myogenic sarcoma, and surgery for tumor resection was performed in June 1999. The tumor was a 20 × 15 × 15 cm well‐defined mass in the peritoneum involving the transverse colon and stomach with peritoneal disseminations and splenic metastasis. Microscopic findings were well‐defined nests composed of small round cells and separated by abundant desmoplastic stroma. Cytologically, the tumor cells consisted of small, round to oval cells with a scant amount of light blue cytoplasm. Immunohistochemically, the tumor cells were positive for anti‐epithelial membrane antigen, vimentin, desmin, neuron‐specific enolase and WT1 protein antibodies. Similar pathologic features with other small round cell tumors may lead to differential diagnostic difficulties that require the application of ancillary diagnostic methods, such as immunohistochemistry and cytogenetic techniques.

Neovascular basement membrane and its significance in the biological behavior of astrocytic tumors

The correlation between morphological changes of neovasculature in astrocytic tumors and tumor biological behavior, were studied using anti‐collagen type IV, von Willebrand factor and Ki‐67 (MIB‐1). Forty‐four astrocytic tumors were histologically classified into Grade 1 (G1) to 4 (G4), according to the Daumas‐Duport classification. To evaluate quantitative changes of the basement membranes (BM) of neovasculatures, the most significantly altered location was chosen and four morphological changes were used as morphological criteria: dissociation, fusion, glomeruloid change and thickening. Basement membrane grades were determined according to these criteria as encountered on the sections. If none of the criteria was found (such as in vesssels in the normal brain) a BM grade 1 (BM‐1) was given, BM‐2 was used when one of the four criteria was noted, BM‐3 for two, BM‐4 for three, and a score of BM‐5 was assigned if all four morphological changes were noted. All cases of G1 and G2 corresponded to BM‐1 or BM‐2; all cases of G3 corresponded to BM‐3; and all cases of G4 corresponded to BM‐4 or BM‐5. Microscopic angiogenesis grading system (MAGS) scores and endothelial Ki‐67 labeling index (eKi‐67 LI) were also correlated with histopathological grading. Significant differences between eKi‐67 LI and MAGS scores were identified among each BM grade, but not between BM‐2 and BM‐1. It is important for tumor grading and behavior to evaluate the degree of morphological changes of BM in astrocytic tumors, especially fusion and glomeruloid change.

Correlation of two argyrophilic nucleolar organizer region counting methods with the Ki-67 labeling index in uterine smooth muscle cell tumors

The argyrophilic nucleolar organizer regions (AgNOR) are silver stained granules that are thought to correlate with cell proliferation activity. Two AgNOR counting methods: the mean AgNOR count (mAgNOR, the mean number of AgNOR granules in 100 cells) and the AgNOR proliferatlve Index (pAgNOR, the percentage of cells exhibiting five or more AgNOR granules per nuclei) have been proposed. In this study, the two counting methods were applied to 58 cases of normal uterine corpus and uterine corpus tumors and were compared with the Ki‐67 labeling Index (Ki‐67 Ll) using MIB‐1 monoclonal antibody and other hlstopathologlcal criteria. Notable differences In the number of AgNOR and the Ki‐67 Ll were observed between benign and malignant smooth muscie tissue. Hlstopathologic features are well correlated to the proliferatlve activity of tumors. Although the most reliable method of predicting malignant potential cannot be determined, the methods outlined by this study are thought to be highly useful In assessing proliferatlve activities.

A case of undifferentiated glioma in a 70-year-old woman

The present case involved a 70-year-old woman who was diagnosed with a right cerebral hemorrhage. Excisional surgery of the hematoma was performed. Grossly, a whitish, solid tumor (1×1×0.8cm in size) was recognized in large, polygonal cells and small undifferentiated cells in a jumbled architectural arrangement with a cartilage component. The large, polygonal cell component was conspicuous and somewhat rhabdoid in appearance and appeared to be an astrocytic tumor showing glial differentiation. The small, undifferentiated cell component resembled tumor cells of a primitive neuroectodermal tumor (PNET). Clinical follow-up of the patient for 2 months after the first operation revealed recurrence with rapid growth. A second operation was performed, but the patient died 8 months after the first operation (2 months after the second). Immunohistochemically, the tumor cells suggesting glial differentiation were positive for glial fibrillary acidic protein (GFAP), S-100, neuron-specific enolase (NSE), and vimentin. PNET-like components in the primary tumor were positive for NSE, GFAP, and S-100, and weakly positive for vimentin and synaptophysin. Each tumor cell was negative for epithelial membrane antigen (EMA), keratin, desmin, actin, myoglobin, neurofilament (NF), and MIC2 protein. The recurrent tumor revealed predominantly PNET-like components; however, only a few tumor cells were positive for GFAP. This appearance suggested that this brain tumor might originate from a common multipotential stem cell. Considering its histopathological and immunohistochemical characteristics, the primary tumor was finally regarded as an undifferentiated glioma with dedifferentiation of the glial component in the recurrent tumor.

Apoptosis in metastatic carcinoma of the central nervous system

High apoptotic indices have been described in pseud‐opalisading areas of glioblastoma multiforme (astrocytoma grade 4). In order to explore further the role of apoptosis in regulating the proliferation in central nervous system (CNS) tumors, we used TdT‐mediated dUTP‐nick endlabeling (TUNEL) methods to compare the frequency and distribution of apoptotic cells in 32 cases of metastatic carcinoma and 54 cases of primary diffuse astrocytomas. Frequencies of apoptotic cells and Bcl‐2 positive cells in metastatic carcinoma were low compared with those observed in high‐grade diffuse astrocytomas and did not correlate with the expression of the p53 protein. These findings suggest that apoptosis does not have a major role in regulating proliferation in metastatic carcinoma of the CNS.