Tatsuhito Yamagami

Long-term follow-up of large or invasive pituitary adenomas

A long-term follow-up study of pituitary adenomas showed that 60 out of 83 patients with mild or moderate suprasellar extension, but only three out of 19 patients with huge or invasive adenomas, were alive at a mean post-operative period of 12.8 and 12 years, respectively. Cerebral ischemic attacks and complications of radiotherapy affected their fate and quality of survival. Patients in the post-computed tomography scan era had a good prognosis, and this may be due partly to the brevity of the postoperative period.

The nd:yag laser in neurological surgery

The Nd:YAG laser has been applied in microneuro-surgery and has been found to be quite effective in removing had and hemorrhagic tumors such as meningiomas, tumors of the deep skull base, or tumors deep in the ventricle. Another indication for the use of the Nd:YAG laser is to open the thick sellar floor in transsphenoidal operations.

An immunohistochemical study of intracranial germ cell tumours.

SummaryHistologically verified intracranial tumours, mainly germ cell tumours of the pineal and suprasellar regions, were studied immunohistochemically using anti-serum of alpha fetoprotein (AFP), human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), human placental lactogen (HPL), pregnancy specific β-1 glycoprotein (SP-1), glial fibrillary acidic protein (GFAP), S-100 and neuron specific enolase (NSE). In germinomas, HCG positive cells were occasionally demonstrated in cells presenting as syncytiotrophoblastic giant cells (STGC), and GFAP and S-100 positive cells were found in the surrounding gliotic lesions. Teratomas were positive for CEA in their epithelial components. Endodermal sinus tumours were positive for AFP, choriocarcinomas for HCG and SP-1, and embryonal carcinomas for AFP, HCG and SP-1. HCG and SP-1 positive cells were demonstrated in STGC. As for the relationship between serum AFP level and tissue localization, many cases presenting a serum AFP level exceeding 220 ng/ml were positive for AFP in tumour tissue.

Astroblastoma of pure type

A rare case of astroblastoma of the pure type occurring in the left occipital lobe of a 54-year-old female is reported. The predominant histologic feature was that of perivascular pseudorosettes. The tumor tissues were not stained by the Mallorys phosphotungstic acid-hematoxylin, but the perikarya of some tumor cells were positively stained for the glial fibrillary acidic protein.

Choriocarcinoma arising from the pituitary fossa with extracranial metastasis: A review of the literature

Since Askanazys first report on a case of primary intracranial choriocarcinoma in 1906, more than 60 cases have been reported so far. We add to that a case of intrasellar choriocarcinoma with suprasellar extension: A 12-year-old girl showed cranial nerve palsies, hypopituitarism, and abnormally high titers of human chorionic gonadotropin (HCG) in blood and in cerebrospinal fluid (CSF). She died 3 months after surgery. At autopsy, an intra- and suprasellar choriocarcinoma, which penetrated through the clivus into the cerebellopontine angle and metastasized remotely to the lungs, was confirmed. This rare case is presented with a thorough review of the literature.

Rat pituitary adenoma and hyperplasia induced by caffeine administration

The effect of caffeine by oral administration on female Wistar rats was studied for 12 months. High concentrations (2000 micrograms/mL) of caffeine caused a decrease in body weight and an increase in the weight of the pituitary gland in these rats. Increased pituitary weight was caused by the growth of a pituitary adenoma or hyperplasia. Pituitary adenomas and instances of hyperplasia were found in 27 of the 40 rats in the caffeine group, compared to 9 of the 30 rats in the control group. The histologic classification used was microadenoma, papillary (or sinusoidal) macroadenoma, and diffuse macroadenomas. These adenomas appeared to be endocrinologically nonfunctioning.

Extent of thermal penetration of Nd-YAG laser--histological considerations.

SummaryThe extent of thermal penetration of Nd-YAG laser was studied histologically. The material was obtained from seven cases of various types of intracranial and extracranial tumours and normal temporal muscle obtained at operation. After irradiation of the tumour surface with the laser, the tumours were removed and depth and width of pathological changes caused by heat were studied. Histologically, materials consisted of a vaporized surface, carbonized, vesicular, necrotic, oedematous layers and surrounding intact brain tumour tissue. There was a direct relationship between the thermal effect and the irradiated thermal energy (watt × exposure time × pulse number). The results showed that the thermal effect was limited to a depth of 6 to 10 mm from the irradiated surface when irradiated 4 times at the power of 90 watts for 2 seconds.

Nd-YAG laser as a surgical tool

SummaryAs neurosurgical operation has necessitated effective haemostatic devices, CO2 and Nd-YAG lasers have been introduced in this field. The CO2 laser was first studied and used in neurological surgery and many problems, such as safety, mobility, and others, were overcome by pioneers.The Nd-YAG laser has been developed mainly for endoscopic surgery. However, we noticed its strong haemostatic effect, used it in neurosurgery and found it to be quite effective in removing tumours. The following properties of the Nd-YAG laser are especially fitted for neurosurgical surgery:1.the laser beam is conducted through a light, thin and flexible quartz fibre.2.penetration of the laser beam into tissues is controlled by the output wattage, and3.the grade of coagulation is controlled by duration of irradiation time and by the output wattage.

Acromegaly with multiple secreting pituitary adenomas

A case of acromegaly with two separate growth hormone-secreting pituitary adenomas is presented. The multiplicity was suspected on computerized tomographic scan and confirmed at transsphenoidal surgery. Possible occurrence of multiple adenomas is discussed.

Histologic study of normal rat brain tissue after neodymiumyttrium aluminum garnet laser irradiation. I. Cerebral hemisphere

We report a histologic study of normal rat brain tissue after neodymium-yttrium aluminum garnet laser irradiation. Morphological changes occurred at a maximum depth of 5 mm after 60-W, 1-second exposure, at a 2-mm distance between the optical fiber tip and the brain surface. Polymorphonuclear leukocyte infiltration into the irradiated area was observed 48 hours after irradiation. After 72 hours, macrophages and fibroblasts appeared; their number increased thereafter. At 1 month, tissue defects attributable to neodymium-yttrium aluminum garnet laser irradiation were small. Gliotic changes were rarely seen. We conclude that 60-W irradiation is harmful to young rats but not to adult rats.