A total of 22 surgical specimens, 16 astrocytomas with various malignancy, 3 brains adjacent to tumor and 3 brains with non-neoplastic lesion, was investigated immunohistochemically for the expression of thrombomodulin (TM). This membrane protein is localized on the vascular endothelium of nearly every human tissue and plays a crucial role in the maintenance of antithrombotic property of the endothelial cells. Although the normal cerebral vessels were negative for TM, the tumor vessels were positive for TM. The increased expression of TM was, however, demonstrated not only in glioblastomas but also in low-grade astrocytomas. Furthermore, the vessels in the brains adjacent to tumor and gliotic brains were also positive for TM. Those observations suggested that the tendency of intratumoral bleeding, which is rather characteristic of glioblastomas, is not simply explained by the altered expression of vascular endothelial TM. In two cases of glioblastoma, not only the blood vessels but also the tumor cells were positive. Considering the mitogenic activity of thrombin, a ligand for TM, the increased expression of TM might be related to the tumor neovascularization and also the tumor growth.

We report here a 74-year-old woman with a skull metastasis from papillary thyroid carcinoma (PTC). In her medical history, she was diagnosed with neurofibromatosis type 1 (NF1) at age 28 years, and she underwent thyroidectomy for PTC at age 52 years and adrenectomy for pheochromocytoma (PC) at age 58 years. She was admitted to our hospital with an increased mass in the forehead. Head computed tomography (CT) showed an expansive, osteolytic, and solid tumor extending from the dura mater into the subcutis, destroying part of the frontal bone. Head magnetic resonance imaging (MRI) revealed that the tumor was chiefly extradural but partially invaded the dura mater. Cerebral angiography showed that the tumor was fed from a branch of the external carotid artery. She underwent surgery, and histological examination revealed that the skull tumor was a metastasis from PTC, indicating that skull metastasis occurred 23 years after curative surgery for PTC. The patient also underwent adjuvant radioiodine therapy. As little is known about skull metastases from PTC, we discuss its characteristics and the extremely rare combined occurrence of PC and PTC in an NF1 patient.

A 42-year-old male presented with the complaint of mild left facial numbness. Magnetic resonance imaging demonstrated a solid tumor in the interpeduncular cistern and a huge arachnoid cyst in the left middle cranial fossa. The tumor appeared isointense to the surrounding cerebral gray matter on T1-weighted images and hyperintense to that on T2-weighted images. The tumor was partially resected. Histological findings were characteristic of hamartoma. The mild left facial numbness was probably due to compression of the left trigeminal nerve by the arachnoid cyst. Asymptomatic hypothalamic hamartomas may occur in adults with atypical clinical presentations.

Eight months after radical surgery for small-cell neuroendocrine carcinoma (SCNC) of the urinary bladder, a 69-year-old man was admitted with a brain tumor in the left frontal lobe. The tumor, about 5 cm in diameter, was intensely but heterogeneously enhanced on computed tomography and magnetic resonance imaging. The tumor was subtotally removed, leaving only the portion adjacent to the anterior horn of the left lateral ventricle. Microscopically, the tumor was composed of diffuse sheets of small tumor cells with round to spindle-shaped nuclei, indistinct nucleoli, scant or absent cytoplasm, and indistinct cell margins. Immunohistochemically, the tumor cells were positive for synaptophysin, neuron-specific enolase, chromogranin A, and keratin. Ultrastructurally, the tumor cells showed classic neurosecretory granules and microvilli in the cytoplasm. The tumor was diagnosed as a brain metastasis from SCNC of the urinary bladder. After surgery, whole-brain radiation therapy of 40 Gy was performed, which succeeded in controlling the residual tumor. However, 4 months after surgery, the patient died of meningeal carcinomatosis. To our knowledge, this is the first report focusing on brain metastasis from SCNC of the urinary bladder. The clinicopathological features and pathological diagnosis of this tumor are discussed.

A total of 14 surgical specimens, including 7 glioblastomas, 3 anaplastic astrocytomas, 2 brains adjacent to glioblastoma and 2 grossly normal brains, were investigated immunohistochemically for the expression of antithrombin III (AT-III), heparan sulfate proteoglycan (HSPG) and thrombomodulin (TM) in the endothelium of microvessels. The immunoreaction to AT-III was of moderate intensity in grossly normal brains, brains adjacent to glioblastoma, and anaplastic astrocytomas, but was only weak in glioblastomas, especially in the capillaries. The immunoreaction to HSPG was constantly intense in the microvessels in all the specimens. Although the immunoreaction to TM was negative or only faint in the microvessels in grossly normal brains, it was moderately to strongly intense in anaplastic astrocytomas and brains adjacent to glioblastoma. The intensity of immunoreaction to TM was variable, from faint to strong in the capillaries, and moderate to strong in larger microvessels in glioblastomas. The present study suggested that the alterations in the expression of those antithrombotic molecules could explain, at least in part, the tendencies for intratumoral hemorrhage as well as intravascular thrombosis in the different areas of malignant gliomas.