ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Ongoing developments in prenatal diagnosis, coupled with methods of pregnancy intervention and termination, have brought the demands of fetal medicine to the doorstep of general pathology. The requirements for comprehensive fetal examinations are remarkably diverse, ranging from gross to microscopic to molecular evaluation. Pathologists, as essential members of a diagnostic team that includes ultrasonographers, obstetricians, perinatologists, medical geneticists, nurses, and others, must obtain data and tissue that facilitates diagnosis, either at the time of examination or at a later date, as indications for testing become apparent. To do this, pathologists must understand a wide variety of artifacts, changes unique to the fetus, and congenital disorders, and they should be familiar with the medical‐legal and ethical demands of practice. This review introduces practical techniques of dissection; acquisition and preservation of data; and tissue collection, storage, and testing. It also includes recommendations for the operation of a fetal pathology service. Approaches to the study of macerated, disrupted, or hydropic fetuses are given, and the work‐up of certain representative conditions (velocardiofacial syndrome, Fanconi anemia, glomerulocystic disease, and trisomy 21) is presented.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;The liver biopsy constitutes an important tool in the evaluation and diagnosis of children with neonatal cholestasis. Giant cell transformation, bile ductular proliferation, and paucity of interlobular bile ducts are the basic morphologic changes. Whereas giant cell transformation constitutes a nonspecific reaction of the liver in newborns and infants, bile duct proliferation and duct paucity have clinical implications. The former signals the need for surgical intervention and the latter a conservative medical approach. Both morphologic patterns may overlap, however, and need to be interpreted by taking the clinical, genetic, and laboratory findings into consideration. This approach emphasizes the close collaboration between the pediatric gastroenterologist and the pathologist for correct identification and management of the disease.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Small round cell tumors (SRCTs) are among the most common solid tumors of childhood. A systematic approach including clinical, routine histologic, immunohistologic, electron microscopic, and/or molecular pathologic studies is essential to arrive at the precise diagnosis that determines the selection of specific therapeutic protocol for each particular case. This article describes the proper triage of the biopsy specimen and the characteristic and diagnostic features of the SRCTs in the basic conventional spectrum. It is inadvisable to rely on a single feature for diagnosis, and every attempt should be made to demonstrate more than one characteristic/diagnostic feature in every case. The nature of tumor cells of an SRCT should be demonstrated by objective criteria such as immunohistologic, ultrastructural, and/or molecular pathologic features.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;In practice, the diagnosis of bone marrow (BM) involvement by neuroblastoma (NB) is made by routine cytologic and histologic examination. The purpose of this review is to provide guidelines for processing and to describe the histologic and cytologic features of BM involvement in NB. It is recommended that two sets of adequate samples of bilateral BM aspirates and biopsies from the posterior iliac crests be obtained. Routinely prepared smears of BM aspirates, Wright‐Giemsa stained, and sections of formalin‐fixed, decalcified BM biopsy specimens are adequate for routine histologic examination and immunoperoxidase stains. Five cytologic patterns of involvement in pretreatment aspirates are described in this review: 1. Isolated undifferentiated small round tumor cells; 2. Diffuse sheets of small round tumor cells; 3. Aggregates of small round tumor cells with nuclear molding; 4. Tumor cells with neuropil in the background, with or without rosettes; and 5. Differentiating neuroblasts and ganglion cells. Four histologic patterns were found in pretreatment biopsies: 1. Undifferentiated neuroblasts without neuropil; 2. Neuroblasts with minimal neuropil; 3. Neuroblasts with moderate to abundant neuropil; and 4. Differentiating neuroblasts and ganglion cells. Posttreatment aspirates and biopsies showed three patterns of involvement: 1. Remnant undifferentiated or poorly differentiated neuroblasts; 2. Maturation with ganglion cells and/or Schwannian differentiation; and 3. Fibrosis with or without isolated neuroblasts and/or Schwann cells. Immunohistochemical stains for neural markers should be used to confirm the neuroblastic nature of the tumor cells.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Hirschsprung disease (HSCR), also calledaganglionosis colior congenital megacolon, represents a diagnostic challenge for pathologists and requires the participation of several pediatric specialists, including gastroenterologists, radiologists, and surgeons. Despite spectacular advances in understanding the genetic basis and pathogenesis of HSCR in the last few years, the ability to identify this condition continues to depend mostly on a skillful pathologic analysis and the use of routine hematoxilyn and eosin (H&E) stains. Acetylcholinesterase (AChE) histochemistry on frozen sections and immunohistochemistry for ganglion cells (GCs) are useful ancillary techniques, but they do not replace the H&E methodology. Adequate sampling of the suspected aganglionic segment, extensive sectioning of colonic biopsies, and clinicopathologic correlation are mandatory for an appropriate assessment of suspected cases. Awareness about differences in the morphologic patterns in “classic” HSCR (short segment disease) and the less‐common long segment variants or total colonic aganglionosis (TCA) is extremely important. Corrective surgery requires ample communication between the pathologist and the surgeon to offer the best possible treatment.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is a neoplasm that typically occurs in the first and second decades of life but may present from infancy to late middle age. ES/PNET generally arises in bone or soft tissue, and examples have been described at most sites. The pathologic nature is defined by a combination of histology, immunohistochemistry, ultrastructure, and molecular genetic abnormalities. The lesions variously termed Ewing's sarcoma, (peripheral) primitive neuroectodermal tumor, peripheral neuroepithelioma, peripheral neuroblastoma, and Askin tumor have been characterized in the past as distinct entities. However, currently all are considered to be members of a common tumor family, the ES/PNET group, which share a limited set of genetic abnormalities defined by fusions of the EWS gene on chromosome 22 with a member of the ets family of transcription factors, most commonly the FLI1 gene on chromosome 11. Neural differentiation is often expressed by ES/PNET, representing the PNET end of the morphologic spectrum. This feature has been linked with clinical outcome, but differences in behavior on the basis of histology are largely overshadowed by clinical prognostic factors: older age, larger size, central site, and presence of metastases all correlate much more powerfully with poor outcome than any single pathologic feature. Recently, specific differences in chromosomal breakpoint fusion type have been closely related to clinical outcome, and this relationship holds great promise for prognostication in the future.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Diagnosis of nodular fasciitis and its clinical and pathologic distinction from other benign and malignant spindle cell proliferations of soft tissue are critical in the clinical management of patients with this lesion. Nodular fasciitis is a “pseudosarcomatous” myofibroblastic‐fibroblastic proliferation that mimics fibromatosis and various types of sarcoma because of its rapid growth and histologic features of cellularity, atypia, nuclear pleomorphism, and mitotic activity. Its characteristics are summarized in this article.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Anaplasia is a powerful adverse prognostic indicator in stage II and higher Wilms' tumor. Criteria for the diagnosis of anaplasia are discussed, along with clues and pitfalls in its diagnosis, and the importance of distinguishing focal from diffuse anaplasia by recently refined criteria is emphasized.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID