Histopathology and molecular genetics of multiple cysts and microcystic (serous) adenomas of the pancreas in von Hippel-Lindau patients.
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Microcystic adenoma and cysts of the pancreas occur sporadically or as a part of von Hippel-Lindau (VHL) disease. The pathology of pancreatic cystic disease in VHL patients has not been well characterized. Furthermore, it is presently unknown whether the alteration of the VHL gene is responsible for the development of the entire spectrum of pancreatic serous cystic lesions. We performed a histopathological analysis of 21 cysts and 98 microcystic adenomas in nine VHL patients with a known germline mutation. In addition, PCR-amplified DNA from 27 pancreatic cystic lesions in three informative patients was studied for allelic deletions with polymorphic markers spanning the VHL gene locus. In all patients, pancreatic lesions were multiple: 21 benign serous cysts, 63 microscopic microcystic adenomas (size <0.4 cm), and 35 macroscopic microcystic adenomas (size >0.5 cm). The average number of lesions per patient was 2.1 benign cysts (range, 0-8), 7.7 (1-37) microscopic microcystic adenomas, and 3 (0-21) macroscopic microcystic adenomas. All lesions showed similar histology and contained prominent fibrous stroma, clear and/or amphophilic, glycogen-rich epithelial cells, endothelial and smooth muscle cells. VHL deletions were detected in all types of pancreatic cystic lesions. The presence of VHL gene allelic deletions in the spectrum of multifocal pancreatic cystic lesions provides direct molecular evidence of their neoplastic nature and integral association with VHL disease. The histopathological and molecular data establish a serous cyst-microcystic adenoma continuum in the development of pancreatic cystic neoplasia in VHL disease. (+info)
Interhemispheric glioependymal cyst associated with agenesis of the corpus callosum--case report.
(74/1471)
A male neonate was admitted because prenatal ultrasonography indicated central nervous system abnormalities. Neurological examination showed no abnormality except for electroencephalographic spike activities. Magnetic resonance imaging revealed a cystic lesion in the left interhemispheric fissure, agenesis of the corpus callosum, and microgyria in the left frontotemporal lobes. Cerebral blood flow (CBF) was diffusely reduced. The cyst wall was partially removed and a cyst-peritoneal shunt procedure was performed. The histological diagnosis was glioependymal cyst. The spike activity disappeared and CBF dramatically improved after the operation. (+info)
Interpretation of radionuclide liver images: do training and experience make a difference?
(75/1471)
Individual observers interpreted images in order to assess their accuracy and sources of error. Seventy-six liver images were presented to nine readers for interpretation. Readers of differing experience participated in the study: four radiology residents, three fellows in nuclear medicine, and two full-time nuclear medicine physicians. A higher incidence of false-positive reading was more common in inexperienced observers (11-50%) and the most correct readings were obtained by staff physicians (88% overall percentage accuracy). Heterogeneity in radionuclide uptake was the most frequently ill-defined nature was the most common false-positive finding in normal cases. Early stages of cirrhosis, mild hepatitis, and rare diseases such as hepatic sarcoidosis were difficult to detect. Skill of interpretation improved with experience, especially in judging heterogeneity of an ill-defined nature, and the rate of accurate readings was proportional to the level of training of the observer. (+info)
Displacement of anterior cerebral vessels in cerebral dynamic study in cases of chronic subdural hematomas.
(76/1471)
About 75-80% chronic subdural hematomas give positive results in a brain scan. The typical scintigraphic finding of chronic subdural hematoma is a diffuse widening and increase of the peripheral activity on the anterior view. In the flow studies subdural hematomas lead occasionally to peripheral activity defects. In two cases of chronic subdural hematoma without typical patterns in a perfusion study as well as in static images, we found a displacement of the anterior cerebral vessels as an indircet sign of space occupation. (+info)
Gliosarcoma associated with a huge cyst--case report.
(77/1471)
A 55-year-old female presented with a unique case of gliosarcoma with a huge cystic component manifesting as loss of consciousness, left-sided hemiparesis, and anisocoria. Computed tomography demonstrated a large cyst in the right frontal lobe, and enhancement of the mural nodule after administration of contrast medium. Emergent operation was performed. Xanthochromic fluid was aspirated, and the tumor was resected. The histological diagnosis was gliosarcoma based on the presence of gliomatous and sarcomatous components. She underwent a second operation because of tumor regrowth 3 weeks after the first operation. The postoperative course was satisfactory during radiation therapy with 60 Gy and chemotherapy. The diagnosis of gliosarcoma was difficult to make preoperatively because of the neuroradiological findings similar to low-grade gliomas. Gliosarcoma should be included in the differential diagnosis of huge cystic tumors. (+info)
Breast scintigraphy with 99mTc-pertechnetate and 67Ga-citrate.
(78/1471)
Radionuclide breast scintigraphy was evaluated as a noninvasive tumor-localizing modality. Technetium-99m-pertechnetate (99mTcO4) demonstrated good correlation between malignancy and postive scintigraphy (88% accuracy in 16 cases of breast carcinoma). The high false-positive rate (29% of proven benign breast disease) limits the use of 99mTcO4 as an aid to differential diagnosis. Gallium-67-citrate (67Ga) is limited as a diagnostic adjunct (localizing in only five of ten breast malignancies). Refined techniques of positioning, shielding, gamma camera imaging, and computer assistance have helped in visualizing abnormal radionuclide accumulation. (+info)
Diagnosis of carcinoma and benign cysts of the breast. The value of needle aspiration.
(79/1471)
Diagnosis of solid breast masses by needle aspiration with cytological examination of the aspirate has been practiced for some time in several centers in this country and abroad. It has been proposed as an alternative to the conventional excisional biopsy for the diagnosis of carcinoma of the breast. At the same time, simple needle aspiration of benign cysts as an office procedure has gained new favor as a means of proving the presence of benign disease at the first office visit and thus avoiding the loss of time, and the expense and worry of surgical excision in a hospital. From a review of the reliability and practical usefulness of both methods, it is concluded that aspiration biopsy for the diagnosis of carcinoma is less reliable than conventional excisional biopsy and offers very little practical advantage. Simple aspiration of cysts, on the other hand, appears to offer a true saving of time, expense and worry, and to be a reliable method, if used properly. (+info)
Effect of focal and nonfocal cerebral lesions on functional connectivity studied with MR imaging.
(80/1471)
BACKGROUND AND PURPOSE: Functional connectivity MR (fcMR) imaging is used to map regions of brain with synchronous, regional, slow fluctuations in cerebral blood flow. We tested the hypothesis that focal cerebral lesions do not eradicate expected functional connectivity. METHODS: Functional MR (fMR) and fcMR maps were acquired for 12 patients with focal cerebral tumors, cysts, arteriovenous malformations, or in one case, agenesis of the corpus callosum. Task activation secondary to text listening, finger tapping, and word generation was mapped by use of fMR imaging. Functional connectivity was measured by selecting "seed" voxels in brain regions showing activation (based on the fMR data) and cross correlating with every other voxel (based on data acquired while the subject performed no task). Concurrence of the fMR and fcMR maps was measured by comparing the location and number of voxels selected by both methods. RESULTS: Technically adequate fMR and fcMR maps were obtained for all patients. In patients with focal lesions, the fMR and fcMR maps correlated closely. The fcMR map generated for the patient with agenesis of the corpus callosum failed to reveal functional connectivity between blood flow in the left and right sensorimotor cortices and in the frontal lobe language regions. Nonetheless, synchrony between blood flow in the auditory cortices was preserved. On average, there was 40% concurrence between all fMR and fcMR maps. CONCLUSION: Patterns of functional connectivity remain intact in patients with focal cerebral lesions. Disruption of major neuronal networks, such as agenesis of the corpus callosum, may diminish the normal functional connectivity patterns. Therefore, functional connectivity in such patients cannot be fully demonstrated with fcMR imaging. (+info)