Search PubMed⌕ Search

Biomedical subjects

Shigeru Ehara

Publications and source records attributed to Shigeru Ehara.

18 recordsLinked to original sources
PubMed2003

Tetraparesis caused by chondroblastoma of the cervical spine: a case report.

STUDY DESIGN: A chondroblastoma of the posterior component of the seventh cervical vertebra with tetraparesis was reported. Imaging studies showed an expansile destructive lesion with mineralization. OBJECTIVES: To emphasize the occurrence of tetraparesis caused by chondroblastoma in the cervical spine. SUMMARY OF BACKGROUND DATA: Chondroblastoma is a rare benign neoplasm of the bone. Only eight cases of chondroblastoma occurring in the vertebra are reported in the literature, including five in the cervical vertebrae. However, there was no reported case of tetraparesis in the literature. METHODS: A 19-year-old man had a tetraparesis caused by chondroblastoma of the posterior component of the seventh cervical vertebra, which invaded the vertebral body with an extraosseous involvement. Imaging studies showed an expansile destructive lesion with mineralization. Curettage of the lesion was performed from both anterior and posterior approaches. The defect of the vertebral body was reconstructed by autologous iliac bone graft with posterior fusion using the Luque instrumentation system. RESULTS: Histologically, the tumor cells were forming cartilage with round or oval nuclei, which often were indented or had a longitudinal groove. There was no sign of local recurrence, and the neurologic deficit had fully recovered 2 years and 3 months after surgery. CONCLUSIONS: Chondroblastoma should be included in the differential diagnosis of lytic expansile destructive lesion of the spine, although there is an extraosseous involvement. Prompt adequate surgery should be performed as soon as possible after establishment of the correct histologic diagnosis to restore the neurologic deficit.

Adult↗
PubMed2003

Magnetic resonance imaging features of epidermoid cyst in the extremities.

BACKGROUND: Epidermoid cyst is a common benign soft-tissue tumor that occurs in the skin. There have been very few descriptions about the magnetic resonance (MR) images of epidermoid cysts in the extremities. MR imaging findings of epidermoid cysts may be characteristic enough to make the preoperative diagnosis possible. The purpose of this paper is to elucidate the MR imaging features of epidermoid cysts arising in the limbs. METHODS: We evaluated the MR images of five patients with an epidermoid cyst in the limbs. MR imaging and other radiological examinations were evaluated. T1-weighted (T1W), T2-weighted (T2W), and Gd-enhanced T1W images were taken in all the patients. RESULTS: The size of the lesion ranged from 2 to 10 cm with an average of 5.2 cm. All the tumors were located in the subcutaneous tissue with a well-circumscribed margin. On T1W MR imaging, the tumor had a slightly high signal intensity in three out of five cases and iso-signal intensity in the remaining two cases. On T2W images, they all showed high signal intensity. Irregular low signal intensity areas were noted in the tumors on both T1W and T2W images. No enhancement was observed inside the tumors. CONCLUSION: Subcutaneous tumor location, well-circumscribed margin, and isosignal to slightly high signal intensity with some heterogeneity on T1W MR images and high signal intensity T2W MR images, and no enhancement are useful features for a diagnosis of epidermoid cyst of the extremity.

Adult↗
PubMed2003

Iridium-192 brachytherapy for hemorrhagic angiosarcoma of the scalp: a case report.

A 60-year-old woman presented with multicentric skin tumors of the head. The histologically proven hemangioendothelioma was bleeding as a result of disseminated coagulopathy. In addition to immunotherapy, 6 MeV electron beam radiotherapy was used for the purpose of hemostasis with a single portal, 20 x 20 cm in size, covering the whole scalp from the top of the head. The radiotherapy was discontinued after 39 Gy/13 fractions/20 days because of the progress in size of a peripheral tumor and the stability of coagulopathy. After another electron boost delivery by two portals focused to exophytic parietal and temporal tumors of 20 Gy/10 fractions, high dose rate brachytherapy with a surface mold technique was performed, 3 Gy/fraction, four fractions/week, for a total of 36 Gy. It induced partial regression of the tumor and complete recovery of platelet counts from 2.5 x 10(4) to 18.2 x 10(4). The tumor disappeared in 3 months. No late side effects occurred, except for permanent alopecia. The patient developed a cervical lymph node metastasis 1 year after and marginal recurrence 2 years after the initial treatment. Both recurrent tumors were successfully treated by 4 MV external photons of 60 Gy/20 fractions/46 days and electron beam irradiation of 60 Gy/20 fractions/29 days, respectively. She has remained disease free for 3 years after the initial presentation.

Brachytherapy↗
PubMed2002

Leiomyosarcoma of the lumbar spine: case report.

STUDY DESIGN: A primary leiomyosarcoma in the L2 vertebral body without any neurologic deficit is reported. The radiologic diagnosis was a metastasis, and the histologic diagnosis was confirmed by transpedicular needle biopsy. OBJECTIVE: To emphasize the occurrence of primary leiomyosarcoma in the lumbar spine. SUMMARY OF BACKGROUND DATA: Leiomyosarcoma is a rare malignant neoplasm of the bone, and only one report of the primary spinal tumor exists. In the case of leiomyosarcoma of the bone, metastasis, most commonly of the uterus or gastrointestinal tract, must be carefully ruled out before the diagnosis of primary leiomyosarcoma in the bone is confirmed. METHODS: Leiomyosarcoma of the second lumbar vertebra in a 47-year-old woman with no neurologic deficit is reported. Imaging findings indicated a nonspecific high-grade lesion. A total spondylectomy of L2 with en bloc excision of the lower half of L1 and the upper third of L3 vertebral bodies was performed after preoperative radiation therapy. The defect of the vertebral body was reconstructed by titanium mesh cage, and T11 to S1 vertebrae were instrumented by the pedicle screw and rod system. RESULTS: The surgical margin was marginal. Histologically, the tumor cells were elongated, with abundant cytoplasm and cigar-shaped nuclei, showing proliferation in fascicles and bundles. No sign of local recurrence or metastasis was evident 2 years and 1 month after surgery. CONCLUSIONS: Leiomyosarcoma should be included in the differential diagnosis of spindle cell tumor of the spine, and it should be confirmed or excluded by immunohistochemical and/or ultrastructural studies. If the expected surgical margin is definitive, a total en bloc spondylectomy should be performed.

Diagnosis, Differential↗
PubMed2001

Spontaneous regression of malignant lymphoma of the lumbar spine.

Spontaneous regression of diffuse B-cell type lymphoma of the lumbar vertebra is reported. A 61-year-old woman experienced spontaneous disappearance of a large psoas mass associated with an infiltrating process of the lumbar vertebrae. The biopsy of the residual change after spontaneous regression revealed reactive foamy histiocytes and small lymphocytes with no atypia. The lesion recurred 7 months later with no systemic treatment in the interim, when the diagnosis of lymphoma was finally made. Spontaneous regression may be related to potentiation of the host immune response, which affects tumor growth.

Female↗
PubMedDate not supplied

Multislice CT angiography through an implantable catheter and port system: early experience in detection of vascular complications during hepatic arterial infusion chemotherapy.

OBJECTIVE: The purpose of this study was to evaluate the use of multislice CT in the evaluation of vascular patency in patients during hepatic arterial infusion chemotherapy of liver tumors. MATERIALS AND METHODS: Thirty-three patients were prospectively examined by CT angiography through the indwelling catheter and port system. Visibility of hepatic arteries and vascular patency were graded 0 to 3 and were compared with digital subtraction angiography (DSA). RESULTS: Average visualization scores of CT angiography and DSA were 1.7 and 2.5, respectively, in common hepatic artery (CHA) and proper hepatic artery (PHA), 2.5 and 2.3 in right hepatic artery (RHA), 2.6 and 2.6 in left hepatic artery (LHA), 2.3 and 2.2 in segmental RHA, and 2.1 and 2.0 in segmental LHA. Stenoses were found in proximal hepatic arteries in 9 on CT angiography and 13 on DSA. Stenoses were found in branches of the hepatic artery in 21 on CT angiography and 16 on DSA. CONCLUSION: The authors' results indicate that multislice CT angiography of the hepatic arteries is equivalent to DSA and may demonstrate vascular complications of hepatic arterial infusion chemotherapy.

Adult↗
PubMedDate not supplied

The substantia nigra in Parkinson disease: proton density-weighted spin-echo and fast short inversion time inversion-recovery MR findings.

BACKGROUND AND PURPOSE: A reduction in the area of the substantia nigra (SN) has been shown in patients with Parkinson disease. The substantia nigra is anteroinferolateral to the red nucleus, and it is important to precisely locate its true anatomic location to accurately measure SN area. Our purpose was to determine the exact location of the substantia nigra by correlating imaging and anatomic findings. We also attempted to quantitate SN area in patients with Parkinson disease compared with that in healthy control subjects on the basis of proton density-weighted spin-echo (SE) and fast short inversion time inversion-recovery (STIR) MR imaging findings. METHODS: In four healthy volunteers, dual-echo SE and fast STIR MR images were obtained in three orthogonal planes and an oblique coronal plane. These images were correlated with anatomic specimens to determine the location of the SN. The area of the SN was also measured on oblique coronal fast STIR images obtained at a plane perpendicular to the SN in 22 patients with Parkinson disease and in 22 age- and sex-matched healthy volunteers. RESULTS: The true anatomic location of the SN, anteroinferolateral to the red nucleus, was accurately identified, not on T2-weighted images, but on proton density-weighted SE images and fast STIR images as an area of hyperintense gray matter. The hypointense area seen on T2-weighted images corresponded to the anterosuperior aspect of the SN and to the adjacent crus cerebri. No statistically significant differences were noted in the size of the SN when the oblique coronal images of patients with Parkinson disease were compared with those of the control groups. CONCLUSION: The SN is located mainly beneath the red nucleus. Its location cannot be determined on the basis of T2-weighted imaging results but rather on the basis of proton density-weighted SE or fast STIR findings. SN volume loss is not found in Parkinson disease, and this finding is compatible with that of recent pathology reports in the literature.

Adult↗