1/82. Infantile myofibromatosis of the triceps detected by prenatal sonography. A routine prenatal sonographic examination at 36 weeks' menstrual age revealed a solid and slightly inhomogeneous soft-tissue tumor on a fetus's left upper arm. The mass in the left triceps brachii muscle measured 8 x 7 x 5 cm at birth. Because of progressive flexion contracture of the left elbow joint, at 2 months of age the infant underwent radical resection of the tumor, sparing some muscle fibers. light microscopic and immunohistochemical studies revealed myofibromatosis. Neither tumor nor functional disorder of the arm was evident 3 years after surgery. ( info) |
| 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 ( info) |
3/82. Pancreatoduodenectomy for neonatal myofibromatosis of the pancreas. myofibromatosis is a rare congenital disorder consisting of one or more fibrous nodules in the skin, soft tissues, bones, and internal organs. The authors report the unique case of a newborn who presented with obstructive jaundice caused by a single myofibroma in the head of the pancreas that was treated successfully by pancreatoduodenectomy on the eighth day of life. ( info) |
4/82. Sporadic unifocal infantile myofibromatosis involving the skull. Case report. Infantile myofibromatosis involving the skull is a benign disease if there is a solitary lesion. However, the multifocal form with skull involvement may portend a lethal course in the 1st year of life if there is involvement of the heart, lungs, or gastrointestinal tract. The authors report the case of a 3-year-old boy with an enlarging left parietal skull lesion that had been present since infancy. Increasing pain and the need to obtain tissue for diagnosis led to resection of the lesion by means of a small craniectomy. Further evaluation revealed no other lesions. A distinctly rare disease is presented, and the need for staging in children younger than 2 years of age is suggested to rule out cardiac, pulmonary, or gastrointestinal involvement. ( info) |
5/82. A case of congenital multiple myofibromatosis developing in an infant. BACKGROUND: Infantile myofibromatosis is marked by the development of firm, discrete, flesh-colored to purple nodules in skin, muscle, bone, and/or subcutaneous tissues. In cases without visceral involvement, the prognosis is excellent with expected spontaneous regression of nodules in 1 to 2 years. Visceral lesions are associated with significant morbidity and mortality generally within the first few months of life secondary to obstruction of a vital organ, failure to thrive, or infection. observation: We present a case of congenital myofibromatosis initially presenting as a single, asymptomatic nodule on the midback of an otherwise healthy 1-month-old white boy. Over the subsequent 6 months, the child developed a left-sided head tilt with the formation of additional myofibromas of the skin and musculature, but without visceral involvement. Physical examinations have continued to show age-appropriate growth and development. CONCLUSION: Clinicians should be aware of this rare but potentially life-threatening entity and consider infantile myofibromatosis in the differential diagnosis of pediatric dermal and subcutaneous nodules, particularly when associated with a new onset of head tilt. Close clinical follow-up is recommended in all cases of infantile myofibromatosis. ( info) |
6/82. del(6)(q12q15) as the sole cytogenetic anomaly in a case of solitary infantile myofibromatosis. We describe a case of light microscopically typical solitary, infantile myofibromatosis in a 6-month old boy. The myofibroblastic differentiation of the tumor was supported by immunohistochemical and ultrastructural analyses. Cytogenetic and FISH analyses revealed a pseudodiploid karyotype with an interstitial deletion of the long arm of one chromosome 6, del(6)(q12q15), as the sole anomaly. The results demonstrate the usefulness of cytogenetics and FISH in distinguishing this type of lesion from infantile fibrosarcoma. To the best of our knowledge this is the first cytogenetic analysis of solitary infantile myofibromatosis. ( info) |
7/82. Solitary form of infantile myofibromatosis: a histologic, immunohistochemical, and electronmicroscopic study of a regressing tumor over a 20-month period. We present the repeated clinical, histologic, immunohistochemical, and ultrastructural observations on a cutaneous myofibromatous tumor over a 20-month period. A 6-day-old Japanese female had a solitary tumor on her left wrist at birth. A biopsy was first performed at 16 days of age, when the tumor was likely fully developed. Thereafter, the tumor gradually regressed. A second biopsy was performed at 58 days of age, when the tumor was already in a phase of early regression. Finally, the tumor was resected at 20 months of age, when it was in a phase of late regression. Our study demonstrated that undifferentiated immature histiocytic cells predominated over spindle cells in the first biopsy specimen, but thereafter the former cells decreased or disappeared in parallel with the increase in the latter cells, which showed characteristics similar to myofibroblasts, in regressing lesions. This evidence suggests that the undifferentiated immature histiocytic cells are precursors of the spindle cells. Spindle cells in the phase of early regression also showed many vacuoles and lipid-like droplets in the cytoplasm, even though they actively produced massive amounts of glycogen. These findings also suggest that tumor regression results from cytoplasmic vacuolation and disruption of spindle cells. Our results are considered to demonstrate, for the first time, the clinical and histologic features of the different developmental or regressive phases of infantile myofibromatosis. ( info) |
| A rare case of solitary infantile myofibromatosis of bone is reported in the right clavicle of a 15-year-old boy. A radiograph demonstrated an osteolytic lesion with a sharp margin and a sclerotic rim. CT revealed a circumscribed lesion with slight expansion of the cortex. On MRI the lesion appeared isointense to muscle on T1-weighted images, bright on T2-weighted images, and showed marked gadolinium enhancement. The patient was well, without evidence of recurrence or metastasis, 4 years and 5 months following resection. ( info) |
| Infantile myofibromatosis is an unusual condition generally presenting in the newborn period. The case being reported is that of a female newborn who had multiple lesions that involved skin, subcutaneous tissue, skeletal muscles, bone, and lungs. The disease was diagnosed because of the easily palpable skin tumors and subcutaneous nodules that were obvious immediately after birth. The diagnosis was established by histopathological examination of one nodule that showed a spindle-celled mesenchymatogenic lesion demonstrating the morphological and immuno-phenotype characteristics of myofibroblastic differentiation. The histologic picture, combined with the clinical manifestations and the imaging findings, are consistent with infantile myofibromatosis. The physical condition of the newborn was excellent and remains so six months later. The tumors of the skin and the subcutaneous nodules have gradually regressed without therapy. At the age of six months, four (4) nodules are palpable; the infant is under continuous observation. ( info) |
10/82. Desmoid tumours of the hand. We report a case of a 3-year-old child with a desmoid tumour of the hand, which is an exceedingly rare location. Desmoid tumours of the hand are difficult to treat because of the many important structures concentrated in the area as well as the infiltrative and recurrent character of these tumours. ( info) |