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Biomedical subjects

J B Beckwith

Publications and source records attributed to J B Beckwith.

188 records · Page 11Linked to original sources
PubMedDate not supplied

Ultrastructure of cellular congenital mesoblastic nephroma.

A detailed ultrastructural description of the cellular variant of congenital mesoblastic nephroma (CMN) is presented and compared to the classical form. Studied were 9 cases of the cellular variant, 6 mixed (cellular/classical) tumors, and 1 classical CMN. The occurrence of a broad selection of ultrastructural features was assessed using a semiquantitative scoring system. The results indicate that cellular CMNs are composed mainly of primitive mesenchymal cells, but also usually contain varying numbers of differentiating fibroblasts and myofibroblasts. This entity thus bears a closer resemblance at the ultrastructural level of organization to infantile fibrosarcoma than to conventional fibrosarcoma. Electron microscopy can be useful in distinguishing this relatively benign entity from the several malignancies with which it is sometimes confused.

Cell Nucleus↗
PubMedDate not supplied

Absence of immunoperoxidase staining for myoglobin in the malignant rhabdoid tumor of the kidney.

Malignant rhabdoid tumor of the kidney, a clinically and pathologically unique tumor of early childhood, has been recently distinguished from nephroblastoma. Skeletal muscle histogenesis has been considered because of its aggressive course and histologic resemblance to rhabdomyosarcoma. Application of an indirect immunoperoxidase technique for myoglobin, an early marker of myogenesis, failed to show the protein in four malignant rhabdoid tumors of kidney. This substantiates the lack of ultrastructural evidence of skeletal muscle differentiation in these tumors.

Child↗
PubMedDate not supplied

Bilateral hyperplastic nephromegaly, nephroblastomatosis, and renal dysplasia in a newborn: a variety of universal nephroblastomatosis.

A preterm boy was born at 34 weeks. Prenatal ultrasonography showed oligohydramnios, fetal ascites, large kidneys, and small thorax. He died 21 h after birth of respiratory insufficiency. Autopsy revealed Potter's-like facies, hypoplastic lungs, ascites, and bilateral nephromegaly (renal weight almost 10 times normal). The kidneys were finely nodular externally, solid, and cerebriform on cut section. Histologically, they showed a diffusely distorted architecture of jumbled lobules, hyperplasia of cortical-type tissue with inconspicuous proximal tubules, relative hypoplasia of medullary tissue, tubulointerstitial dysplasia, and perilobar nephrogenic rests. The renal features represent a variety of the universal or panlobar (also called pancortical or infantile) type of nephroblastomatosis. To our knowledge, this is only the third such case reported. In the brain, each lateral ventricle contained a yellow gelatinous mass. Histologically, the masses consisted of a pseudomyxoid matrix with delicate fibers and focal adipocyte clusters, all confined within choroid plexus. We consider these lesions fibrolipomatous hamartomas.

Adult↗
PubMedDate not supplied

Ossifying renal tumor of infancy: a clinicopathologic study of nine cases.

We studied nine ossifying renal tumors of infancy (ORTI), including all five previously reported cases. There were eight boys and one girl ranging in age from 6 days to 14 months. Gross hematuria was the presenting sign in all nine patients. Eight tumors arose in the left kidney and six in the upper pole. All seven patients with follow-up information were free of recurrence. All lesions were attached to a renal papilla and presented mainly within the calyceal lumen. Two resembled staghorn calculi clinically. All tumors contained varying proportions of osteoid, osteoblastic cells, and spindle cells. The spindle cell component had features strongly suggesting that they represented hyperplastic intralobar nephrogenic rests (ILNR). The proportion of osteoid and degree of osseous maturation increased with increasing age of the patient. ORTI is a distinctive clinicopathologic entity, possibly representing a distinctive interaction between ILNR in the renal papilla with distal collecting duct or urothelial cells in the developing kidney.

Black People↗
PubMedDate not supplied

Wilms tumor.

Wilms tumor is the most common primary malignant renal tumor of childhood, representing about six percent of all childhood cancers in the United States. Developments in surgery, radiation therapy, and chemotherapy have led to a dramatic change in the prognosis for most patients, and Wilms tumor has become a paradigm for multimodal treatment of a pediatric malignant solid tumor. The authors review the progress made in the diagnosis and management of children with Wilms tumor.

Child↗
PubMedDate not supplied

Effect of chemotherapy on human growth plate.

Histologic specimens of the distal femoral growth plates of 10 patients treated surgically for osteosarcoma were examined retrospectively. Eight of the patients received preoperative chemotherapy. None of the specimens showed complete growth arrest. The gross thickness of the plates was preserved. Columnar arrangement of the cells was minimally disrupted. The number of proliferative cells in each column was decreased, and the number of hypertrophic cells, was increased slightly. The metaphysis showed longitudinal trabeculations with a high chondroid content. Growth arrest lines were evidenced by transverse trabeculations with a high osteoid content. Our findings provide histologic support for previous clinical studies. Absence of complete growth arrest and evidence of a resumption of growth are relevant in planning limb salvage procedures in patients receiving pre- and postoperative chemotherapy for skeletal malignancy.

Adolescent↗