1/5. Solitary renal myofibromatosis: an unusual cause of infantile hypertension.INTRODUCTION: Renovascular disease accounts for the vast majority of cases of infantile hypertension with complications resulting from umbilical arterial catheterization predominating in the neonatal period and fibrodysplastic lesions of the renal artery predominating outside the neonatal period. We report a previously undescribed cause of renovascular hypertension: solitary renal myofibromatosis. CASE REPORT: A 9-month-old male infant was transported to the intensive care unit at Children's Hospital in Denver, colorado, for evaluation and treatment of a dilated cardiomyopathy and severe systemic hypertension. The child was full-term with no perinatal problems. Specifically, the child never required umbilical arterial catheterization. He was well until 6 months of age when his parents noted poor weight gain. At 9 months of age, he was evaluated at the referral hospital for failure to thrive. On examination he was noted to have a blood pressure of 170/110 mm Hg, but no other abnormalities. A chest radiograph showed cardiomegaly. Laboratory studies demonstrated normal electrolytes, blood urea nitrogen, and creatinine. However, urinalysis demonstrated 4 protein without red blood cells. An echocardiogram showed severe left ventricular dilatation with an ejection fraction of 16%. On admission the child was noted to be cachectic. His vital signs, including blood pressure, were normal for age. The physical examination was unremarkable. serum electrolytes, blood urea nitrogen, and creatinine were normal. Echocardiographic studies suggested a dilated hypertrophic cardiomyopathy. He was started on digoxin and captopril. Subsequently, he demonstrated episodic hypertension ranging from 170/90 to 220/130 mm Hg. A repeat echocardiogram 24 hours after admission demonstrated a purely hypertrophic cardiomyopathy. verapamil and nifedipine were added to the treatment regimen in an effort to better control the blood pressure without success. urine and blood for catecholamines and plasma renin activity, respectively, were sent and treatment with phentolamine instituted because of a possible pheochromocytoma. A spiral abdominal computerized tomographic scan revealed a markedly abnormal right kidney with linear streaky areas of calcification around the hilum and also an area of nonenhancement in the posterior upper pole. The adrenals and the left kidney were normal. Doppler ultrasound revealed a decrease in right renal arterial flow. The urinary catecholamines were normal and surgery was scheduled after the blood pressure was brought under control by medical treatment. At surgery, tumorous tissue and thrombosis of the renal artery were found in the right upper pole. A right nephrectomy was performed. Pathologic examination of the kidney showed the presence of a diffuse spindle cell proliferation in the interstitium of the kidney. The angiogenic/angiocentric character of the proliferation was demonstrated in several large renal vessels. The lumen of most vessels was narrowed and some vessels were totally occluded with recanalization and dystrophic calcifications observed. Immunostaining of the tumor demonstrated strong desmin and vimentin positivity and minimal actin positivity in the spindle cells. Mitotic activity was not noted in the spindle cell process. These pathologic changes were consistent with a diagnosis of infantile myofibromatosis (IM). The child's preoperative plasma renin activity was 50 712 ng/dL/h (reference range, 235-3700 ng/dL/h). DISCUSSION: The causes of systemic hypertension in infancy are many although renal causes are by far the most common. Renal arterial stenosis or thrombosis accounts for 10% to 24% of cases of infantile hypertension. renal artery thrombosis is usually a consequence of umbilical arterial catheterization, which can also lead to embolization of the renal artery. renal artery stenosis may result from fibrodysplastic lesions (74%), abdominal aortitis (9%), a complication of renal transplantation (5%), and ren- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/5. Infantile myofibromatosis.Infantile myofibromatosis (IMF) is a rare tumour with a wide spectrum of disease activity ranging from a solitary cutaneous nodule through to a multicentric form with widespread visceral involvement. It is characterised by its unique ability to spontaneously regress and has a typical histological appearance of actin-positive fibroblasts arranged in whorls or fascicles and vessels in a pericytomatous pattern. A male infant with multiple lesions involving the subcutaneous tissue and bone from birth is described and followed-up for two years. Treatment of IMF is dependent on the location of the tumour/s with surgery or chemotherapy reserved for rapidly progressive or symptomatic disease. However, due to the low rate of recurrence and the possibility of spontaneous tumoral regression, therapeutic abstention, as practised in our patient, is justified.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |
3/5. Malignant myopericytoma: expanding the spectrum of tumours with myopericytic differentiation.AIMS: The spectrum of tumours showing myopericytic differentiation is increasingly being defined and includes lesions such as myofibroma and infantile haemangiopericytoma. Here we seek to describe for the first time and clinicopathologically characterize examples of malignant myopericytoma. methods AND RESULTS: Five cases of malignant myopericytoma were identified in the authors' consultation files. Immunostains were performed and clinical information was obtained. Tumours arose in three females and two males (median age 67 years, range 19-81 years) on the neck, arm, thigh and foot. One patient presented with disseminated metastases. One patient had a prior history of multiple benign myopericytomas in the same location. Four patients developed metastases and three died within 1 year. Tumours were composed of highly mitotic myoid-appearing ovoid-to-spindle cells showing at least focally striking perivascular orientation resembling that seen in benign myopericytoma; three cases were focally fascicular and three showed thin-walled branching vessels. All tumours showed at least focally prominent positivity for smooth muscle actin. One case showed dot-like desmin positivity. CONCLUSIONS: In reporting examples of malignant myopericytoma, we further characterize and broaden the morphological spectrum of myopericytic neoplasms. Available data indicate that malignant myopericytomas are associated with aggressive clinical behaviour.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |
4/5. Multifocal infantile myofibromatosis and generalized fibromuscular dysplasia in a child: evidence for a common pathologic process?Infantile myofibromatosis (IM) is a condition characterized by the formation of spindle cell tumors of skin, soft tissue, and viscera. Although small vessel involvement by the process is a frequently identified and indeed diagnostically useful histological finding, involvement of large vessels is not widely reported. fibromuscular dysplasia (FMD) is a noninflammatory arteriopathy characterized by intimal, medial, and/or adventitial fibroplasias leading to luminal compromise and aneurysm formation. Although venous disease has been reported, involvement of arterioles and viscera has not been identified. We report a patient in whom IM was diagnosed, on the basis of multiple soft tissue tumors present from birth, who subsequently developed generalized and ultimately fatal FMD. These two conditions exhibit overlapping pathologic features, including pronounced intimal fibroplasia. Their occurrence in a single individual may provide insights into the pathogenesis of both conditions, suggesting that they represent part of the same spectrum of vascular myofibroblastic proliferations.- - - - - - - - - - ranking = 0.66666666666667keywords = vessel (Clic here for more details about this article) |
5/5. Perivascular myoma of myopericytoma and myofibromatosis-type arising in a chronic scar.We describe a case of a cutaneous perivascular myoma with features overlapping between the myofibromatosis and the myopericytoma type. The patient is a 58-year-old woman with a painless plaque-like and multinodular lesion in the pretibial dermis and subcutaneous tissue. She had repeated trauma to this site, first in her early youth that left an area of hyperpigmentation, and then again at age 40. The biopsy showed a biphasic pattern with a myofibromatosis-type component composed of spindle cell myoid nodules and more cellular round cell areas. The myopericytoma-like areas appeared to be infiltrating along vessels. These areas contained aggregates of immature-appearing cells arranged concentrically around vascular lumina in a manner reminiscent of pericytes. Immunohistochemical stains showed focal positivity for smooth muscle actin. Immunohistochemical and ultrastructural studies have showed these pericyte-like cells to be of a myoid origin. The reason for the neoplastic proliferation of perivascular myoid cells is presently unknown. The association of trauma and neoplastic transformation of the skin is rare. We report the first case of a cutaneous perivascular myoma arising in a chronic scar.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |