Biomedical subjects

Hidetoshi Ikeda

Publications and source records attributed to Hidetoshi Ikeda.

21 records · Page 2Linked to original sources

PubMed2002

Clinicopathologic study of 123 cases of prolactin-secreting pituitary adenomas with special reference to multihormone production and clonality of the adenomas.

BACKGROUND: Prolactinoma is the most invasive type of pituitary adenoma and is generally believed to be well-differentiated adenoma and to produce only prolactin (PRL). The factors related to the various biologic behaviors occurring in patients of different ages and sexes await clarification. Since different immunophenotypes of adenoma may show different biologic behaviors and responses to medical agents, the authors examined hormone production and tried to clarify the clonality of plurihormonal prolactinoma. METHODS: Clinicopathologic factors were studied in 123 patients with prolactinomas (40 males and 83 females). The specimens were fixed in either 10% neutral buffered formalin or 70% alcohol and used for light microscopy. Alcohol-fixed tissue was used to extract DNA from 26 samples obtained from female patients for human androgen receptor gene (HUMARA) assay. RESULTS: Sixty one cases (50%) were pure prolactinoma and 62 cases (50%) were plurihormonal prolactinoma. Spearman rank correlation analysis revealed a significant relationship between age and serum PRL level (P = 0.0002), age and tumor volume (P < 0.0001), and tumor volume and serum PRL level (P < 0.0001). Multiple regression analysis showed a significant correlation only between tumor volume and serum PRL level. The Mann-Whitney U test revealed that prolactinomas associated with higher PRL levels, larger adenomas, and higher ages were significantly more invasive to the cavernous sinus and that male patients had significantly higher PRL levels and larger adenomas. The HUMARA assay disclosed that 11 of 13 plurihormonal prolactinomas (85%) were compatible with monoclonal origin. CONCLUSIONS: The current results suggest that not only can various hormones other than PRL be secreted by prolactinoma, but also that most multihormone-producing prolactinomas are monoclonal in origin.

Adolescent↗

PubMed2002

[Recurrence of intracranial germinoma initially treated with chemotherapy only].

Irradiation for intracranial germinoma may be associated with significant neuroendocrinological sequelae, so the establishment of lower effective doses of radiation is desirable. Eight consecutive patients with intracranial germinoma underwent combination chemotherapy with BEP (bleomycin, etoposide, and cisplatin) or PE (cisplatin and etoposide) without irradiation between 1996 and 1997. The diagnosis was based on endoscopic or stereotactic biopsy, or transsphenoidal surgery in 7 cases. These 7 patients obtained complete response (CR) after treatment with chemotherapy only. The diagnosis of pure germinoma was based on neuroradiographic appearances and the normal levels of tumor markers in patients with suprasellar and pineal-region germ cell tumors. Although all patients obtained CR, 5 patients relapsed at a mean period of 19 months after the initial therapy. The mean follow-up period was 53 months. Two of these 5 patients had recurrence around the ventricle wall. Additional chemotherapy and total ventricle irradiation (24 Gy) achieved CR, but delayed seeding in the optic nerves outside the irradiated field was detected. One patient suffered peritoneal dissemination via a ventriculoperitoneal shunt with intracranial dissemination. Another patient obtained CR after PE therapy, but there was not histological verification. However, 35 months after the initial therapy, surgical extirpation of the recurrent tumor revealed immature teratoma. One patient refused treatment for recurrence at the initial tumor site and died 42 months after the initial treatment. Adequate initial therapy is absolutely essential for the treatment of intracranial germinoma. The chemotherapy regimens in use today cannot be recommended as initial therapy without irradiation because of the high recurrence rates.

Adolescent↗

PubMed1995

Detection of Heterozygous Mutation in the Retinoblastoma Gene in a Human Pituitary Adenoma Using PCR-SSCP Analysis and Direct Sequencing.

Genomic deoxyribonucleic acid from surgical specimens of 25 pituitary adenomas was screened for the presence of mutations in the tumor suppressor gene retinoblastoma gene, using polymerase chain reaction and single-strand conformation polymorphism analysis, followed by direct deoxyribonucleic acid sequencing. Mutation causing an amino acid change was found in one of the 25 pituitary adenomas. The mutation site was in exon 19 (codon 621) of the retinoblastoma gene. In addition, there were three types of silent mutations in introns of the gene. The patient in whom the retinoblastoma mutation was identified had a tumor with high clinical malignancy, a high percentage of c-myc protein-labeled cells, and a diagnosis of plurihormonal pituitary adenoma based on the presence of cells immunoreactive for five pituitary hormones. This article suggests that point mutation of retinoblastoma gene is rare in human pituitary adenomas but may provide a marker for aggressive pituitary adenoma.

Journal Article↗