(1/770) Focal aneurysmal dilatation of subchorionic vessels simulating chorioangioma.

Subchorionic vascular aneurysms of the placenta are rare lesions and may present confusion with chorioangioma or focal mesenchymal dysplasia on sonography. To our knowledge, the findings of placental aneurysms have not been reported in the ultrasound literature. We present a case with detailed sonographic evaluation, including spectral and color Doppler and pathological analysis, that was mistaken for chorioangioma prenatally. Knowledge of this benign entity may allow the sonologist to recommend conservative management in similar cases.  (+info)

(2/770) Renal carcinogenesis, hepatic hemangiomatosis, and embryonic lethality caused by a germ-line Tsc2 mutation in mice.

Germ-line mutations of the human TSC2 tumor suppressor gene cause tuberous sclerosis (TSC), a disease characterized by the development of hamartomas in various organs. In the Eker rat, however, a germ-line Tsc2 mutation gives rise to renal cell carcinomas with a complete penetrance. The molecular mechanism for this phenotypic difference between man and rat is currently unknown, and the physiological function of the TSC2/Tsc2 product (tuberin) is not fully understood. To investigate these unsolved problems, we have generated a Tsc2 mutant mouse. Tsc2 heterozygous mutant (Tsc2+/-) mice developed renal carcinomas with a complete penetrance, as seen in the Eker rat, but not the angiomyolipomas characteristic of human TSC, confirming the existence of a species-specific mechanism of tumorigenesis caused by tuberin deficiency. Unexpectedly, approximately 80% of Tsc2+/- mice also developed hepatic hemangiomas that are not observed in either TSC or the Eker rat. Tsc2 homozygous (Tsc2-/-) mutants died around embryonic day 10.5, indicating an essential function for tuberin in mouse embryonic development. Some Tsc2-/- embryos exhibited an unclosed neural tube and/or thickened myocardium. The latter is associated with increased cell density that may be a reflection of loss of a growth-suppressive function of tuberin. The mouse strain described here should provide a valuable experimental model to analyze the function of tuberin and its association with tumorigenesis.  (+info)

(3/770) Color Doppler sonography of focal lesions of the skin and subcutaneous tissue.

We evaluated with color Doppler sonography 71 visible and palpable nodules of the skin and subcutaneous tissue from 51 patients. The nodules were classified as avascular (type I), hypovascular with a single vascular pole (type II), hypervascular with multiple peripheral poles (type III), and hypervascular with internal vessels (type IV). Of the 32 malignant nodules, 9% showed a type I pattern, 50% had a type III pattern, and 41% had a type IV pattern; of the 39 benign nodules, 86% showed a type I pattern and 14% had a type II pattern. The sensitivity and specificity of hypervascularity in malignant lesions were 90% and 100%, respectively, whereas the sensitivity and specificity of hypovascularity in benign lesions were 100% and 90%, respectively. The authors conclude that color Doppler sonography is able to increase the specificity of ultrasonography in the evaluation of nodular lesions of the skin.  (+info)

(4/770) Third International Meeting on von Hippel-Lindau disease.

Five years after the identification of the von Hippel-Lindau (VHL) gene, physicians, scientists and concerned VHL family members met to review the current state of knowledge on the diagnosis and treatment of VHL and to summarize the latest information on the biochemistry of the VHL protein (pVHL). The NIH and University of Pennsylvania groups reported the detection of germ-line mutations in 100% (93 of 93) of VHL families studied. Several studies determined the frequency of VHL germ-line mutations in individuals with a single manifestation of VHL without a family history of VHL. National groups to improve the diagnosis and treatment of individuals with VHL disease have been established in Great Britain, Denmark, France, Holland, Italy, Japan, Poland, and the United States. Evidence for the existence of genes that modify the expression of VHL was presented. The VHL protein appears to have several distinct functions: (a) down-regulation of hypoxia-inducible mRNAs; (b) proper assembly of the extracellular fibronectin matrix; (c) regulation of exit from the cell cycle; and (d) regulation of expression of carbonic anhydrases 9 and 12.  (+info)

(5/770) Complications of angioma surgery--personal experience in 191 patients with cerebral angiomas.

In the last years, treatment decisions of arteriovenous malformations (AVMs) were influenced by the improvement of stereotactic radiosurgery and were revolutionized by development of embolization techniques. The aim of this report was to examine the results, effectiveness, and complications associated with angioma surgery. 191 patients with AVMs were operated by the first author between 1981 and 1996. Angioma localization was distributed as follows: frontal 51 (26.7%), temporal 44 (23%), parietal 45 (23.6%), and occipital 24 (12.6%). Twelve (6.3%) AVMs were located in the cerebellum and 15 (7.9%) in other deep regions. Twenty-nine (15.2%) AVMs were associated with single or multiple aneurysms. The preoperative symptoms were hemorrhage (50.3%), seizure (33.5%), headache (23.0%), focal neurological deficits (12.6%), and other minor symptoms. In 9.9%, the disease remains preoperatively asymptomatic. Based on the Spetzler/Martin scale (S/M), 38 patients were grade I, 39 grade II, 52 grade III, 39 grade IV, and 23 grade V. The following severe complications were observed: postoperative hemorrhage in 13 (6.8%), infection in six (3.1%), infarction in two (1.0%), and death in three (1.6%). The risk for postoperative complications was related to the preoperative S/M grade of the AVM. Severe complications only occurred in AVM grades IV and V. In 62 patients with grade IV and V AVM, three patients died (4.8%) and 12 showed neurological deterioration (19.4%). Only 3/129 (2.3%) patients with grade I-III AVM deteriorated postoperatively. No severe complications were observed in preembolized and recently operated patients. Microsurgical management of cerebral AVMs seems to be a reasonably safe procedure especially in grade I-III AVMs, with a mortality of less than 2%. With enough experience and exact attention to detail, the experienced neurosurgeon can remove many of these AVMs with a minimum of risk to the affected patient. Although hemorrhage from an AVM can be disabling or deadly, the course in many nonoperated high-grade AVMs (S/M grades IV and V) can be quite benign, if compared with their surgical risk. This may justify conservative treatment or treatment with radiosurgery in some high-grade (S/M grades IV and V) angiomas, especially in elderly patients.  (+info)

(6/770) A novel animal model for hemangiomas: inhibition of hemangioma development by the angiogenesis inhibitor TNP-470.

Hemangiomas represent the most frequent tumors of infancy. However, the pathogenesis of these tumors is still largely unknown, and current treatment of juvenile hemangiomas remains unsatisfactory. Here we present a novel animal model to study proliferating hemangiomas and to evaluate the effect of angiostatic compounds on their growth. Intraperitoneal (i.p.) infection of 4-day-old rats with murine polyomavirus resulted in the development of multiple cutaneous, intramuscular (i.m.), and cerebral hemangiomas with 100% frequency. Histological examination of the brain revealed the formation of immature lesions as soon as 4 days postinfection (p.i.). The subsequent exponential growth of the hemangiomas, both in number and size, was associated with severe hemorrhage and anemia. The cerebral, cutaneous, and i.m. lesions consisted of blood-filled cysts, histologically similar to human cavernous hemangiomas and stained positive for proliferating cell nuclear antigen, urokinase-type plasminogen activator, and vascular endothelial growth factor. Mature cerebral hemangiomas also expressed von Willebrand factor. Cerebral lesions caused death of the untreated animals within 19.2 +/- 1.1 days p.i. Remarkably fewer and smaller hemangiomas developed in animals that had been treated s.c. with the angiogenesis inhibitor TNP-470. Accordingly, TNP-470 (50 mg/kg), administered twice a week from 3 days p.i., significantly delayed tumor-associated mortality [mean day of death, 28.2 +/- 3.3 (P < 0.001)]. Even if therapy was initiated when cerebral hemangiomas were already macroscopically visible (i.e., 9 days p.i.), a significant delay in hemangioma-associated mortality was observed. Also, the IFN-inducer polyinosinic-polycytidylic acid caused a delay of 9 days (P < 0.005) in tumor-associated mortality when administered i.p. at 5 mg/kg, twice a week, starting at day 3 p.i. The model described here may be useful for investigating (a) the angiogenic mechanism(s) underlying hemangioma progression; and (b) the effect of anti-angiogenic compounds on vascular tumor growth.  (+info)

(7/770) In utero diagnosis of cardiac hemangioma.

Fetal cardiac hemangioma is rarely diagnosed prenatally. We present here a fetus with such a tumor diagnosed at 28 weeks' gestation. With the use of fetal echocardiography, a mixed echogenic mass protruding outward from the right atrial wall was observed. Moderate amounts of pericardial effusion were also found. Although no apparent blood flow signal was detected in the mass, fetal echocardiography showed signs suggestive of a hemangioma. Differential diagnosis, management and prognosis are discussed.  (+info)

(8/770) Clinical significance of intracranial developmental venous anomalies.

OBJECTIVES: Venous angiomas, or developmental venous anomalies (DVAs), represent the most often occurring cerebral vascular malformation. The clinical significance of a DVA is, however, at present unclear. METHODS: A retrospective analysis was carried out on two series of consecutive cranial MRIs performed between January 1990 and August 1996 in a university department of neuroradiology and in a large radiological private practice. The medical records of all patients in whom a DVA was diagnosed were screened to identify the specific complaint which necessitated the imaging procedure. RESULTS: A total of 67 patients with DVA could be identified. In 12 patients an associated cavernoma was found. The main reason for performing the MRI was the evaluation of seizures or of headaches. In all patients with DVA in whom an intracerebral haemorrhage was diagnosed an associated cavernoma was present at the site of the haemorrhage. None of the 67 patients showed an association between the complaints that led to the MRI and the location of the DVA. CONCLUSIONS: DVAs do not seem to be associated with a specific clinical presentation. In a significant percentage of cases, however, coexisting cavernomas are found which have a defined bleeding potential and should be treated independently of the DVA. This study supports the hypothesis that DVAs are a congenital abnormality of venous drainage without clinical significance.  (+info)