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Biomedical subjects

T W Bauer

Publications and source records attributed to T W Bauer.

At least 91 records · Page 5Linked to original sources
PubMed1990

Hepatic giant cell carcinoma. An ultrastructural and immunohistochemical study.

Hepatocellular carcinoma with osteoclast-like giant cells (hepatic giant cell carcinoma [HGCC]) is a rare entity, with only three cases reported. The tumor is histologically similar to giant cell tumor (GCT) of bone, and the origin of the multinucleated giant cells and mononuclear stromal cells has not been determined. The purpose of this report is to present a case of this rare tumor and compare its ultrastructural and immunohistochemical features with those of a conventional GCT of bone. Histologically, the HGCC consists of sheets of osteoclast-like giant cells with a background of mononuclear cells. The giant cells lack the pleomorphism seen in hepatocellular carcinomas with anaplastic giant cells. At the light microscopic level, most of this tumor was nearly identical to a GCT of bone, but several microscopic fields (less than 5% of the tumor) had the histologic appearance of a "usual" hepatocellular carcinoma. The hepatic tumor was negative for HAM 56, epithelial cytokeratins, muramidase, and alpha-1-antitrypsin, with only focal positivity for chymotrypsin in mononuclear and giant cells. The GCT was strongly positive for alpha-1-antitrypsin and chymotrypsin in both the mononuclear and giant cells and showed focal, weak staining for AE1 and AE3 in the mononuclear stromal cells. Ultrastructurally, both mononuclear and giant cells of the HGCC showed features typical of hepatocellular carcinoma. Although the patient presented in this report died, the pattern of growth was different from most hepatocellular carcinomas. The overall histologic features of this tumor are distinctive and appear to justify separating this variant from other types of hepatocellular carcinoma.

Adult↗
PubMed1990

A prospective comparison of DNA quantitation by image and flow cytometry.

Advances in computer and video technology suggest that image analysis may be practical method of measuring DNA that also allows visual confirmation of cell type. The purpose of this study was to prospectively compare DNA quantitation from 92 solid tumors in which DNA indices had been measured by image analysis of touch preparations (CAS 100) and flow cytometry of cell suspensions (FACScan). For 81 cases, there was excellent correlation between the two methods. For nine cases, however, an aneuploid population, usually near tetraploid, was identified by image but not by flow cytometry. Three cases had aneuploid peaks by flow cytometry that were not identified by image. Although these methods show good correlation, rare populations may be missed by CAS, presumably because of sampling errors in the touch preparation. Aneuploid populations may also be missed by flow cytometry, either because of cell loss during processing or because visual identification by image can increase sensitivity.

Adenocarcinoma↗
PubMed1990

DNA quantitation by image cytometry of touch preparations from fresh and frozen tissue.

Using formalin-fixed, paraffin-embedded tissue for DNA quantitation has several disadvantages, including sacrifice of tissue and relatively poor resolution. DNA quantitation of touch preparations by image cytometry correlates well with flow cytometry, and analysis of touch preparations made from frozen tissue may offer an alternative method for retrospective studies. The authors compared the results of DNA quantitation of fresh and frozen tissue touch preparations in 59 solid tumors. For 54 cases there was excellent correlation. In three cases with multiple aneuploid peaks, the same populations were identified by each method, but different proportions of cells from each stemline were present in the fresh and frozen samples. In two cases there was a discrepancy between the DNA indices; the imprints showed different cell morphologic characteristics, suggesting different stemlines or areas of tumor differentiation. The authors conclude that DNA quantitation from touch preparations of frozen tissue by image cytometry provides a desirable alternative to sacrificing formalin-fixed tissue.

Cell Separation↗
PubMed1990

Nodular fasciitis presenting as an eyelid mass.

A case of nodular fasciitis occurring in the eyelid is presented. The clinical and pathologic features of this rare cause of an eyelid mass are discussed. Nodular fasciitis should be considered in the pathologic differential diagnosis of connective tissue tumors of the periorbital region. It is important not to confuse nodular fasciitis with fibrosarcoma, as simple excision is curative for this condition.

Child↗
PubMed1990

Making core decompression work.

Meaningful assessment of a treatment modality for osteonecrosis (ON) must take into account a number of factors: (1) an accurate diagnosis, (2) consistent staging of the disease process, (3) understanding of the variability of the disease, (4) consistent application of the treatment modality (or the surgical technique), and (5) a clear understanding of the goal of the treatment used. This article reviews the important steps of a diagnostic algorithm that has been used to accurately diagnose and stage the disease process of ON. A consistent surgical technique with clearly defined goals is also outlined. The results of two clinical studies that were based on these diagnostic and therapeutic philosophies and that assess the role of core decompression in the treatment of ON are reviewed. The first study compared core decompression to conservative management in a prospective randomized study of 55 hips. Decompression provided more predictable pain relief and changed the indications for further surgical intervention more consistently than did conservative management. The second study represents a preliminary review of a ten-year study of the decompression procedure; it showed that core decompression was particularly useful in Stage I and Stage II ON. Roentgenographic stabilization was most predictable for Stage I hips. Core decompression can be a safe, effective, and predictable procedure in the treatment of Stage I and Stage II ON.

Adult↗
PubMed1989

The rate of vascularization of coralline hydroxyapatite.

Coralline hydroxyapatite (CHAP) is a porous, biocompatible bone-graft substitute manufactured by the Replamineform process. The use of this material in the experimental and clinical settings for maxillofacial onlay grafting has been recently described. This study was designed to quantitate the rate of vascularization of coralline hydroxyapatite when used in an onlay application to membranous bone in an animal model. Sixteen onlay grafts of coralline hydroxyapatite (0.5 X 0.5 X 1.0 cm Interpore 200) were placed in a subperiosteal location on the nasal dorsum of 2- to 3-kg male New Zealand white rabbits. The grafts and nasal bones were harvested en bloc at 1, 2, 3 and 4 weeks after onlay. Prior to harvest, injectable silicone visualizing agent (Microfil*) was injected by means of carotid artery cutdown. The decalcified specimens were examined on a digitizing pad to count the number of vessels appearing in the blocks of hydroxyapatite. Counting was summed and integrated by an Apple IIe microcomputer. A significant difference (p less than 0.05) was noted in both the number of vessels and the fraction of implants infiltrated by vessels between 1 and 4 weeks. The usefulness of these previously undescribed data may be in their extrapolation to onlay grafts of coralline hydroxyapatite in maxillofacial reconstruction in humans.

Animals↗
PubMed1989

Automation of immunohistology.

Despite the introduction of enzyme-based immunohistology in the late 1960s and early 1970s by Nakane and Taylor, both methodologic and interpretative aspects of this important technology remain, in large part, manual and not automated. Similar approaches to the analysis and sorting of cell markers by immunofluorescence have been automated for a decade using flow cytometry. Automation of both procedural and interpretative aspects of immunohistology has been the focus of greater commercial and professional attention in recent years. Automated immunostaining is accorded several advantages, including cost savings, uniformity of slide preparation, and reduction of procedural human errors. Automated interpretation may not be necessary or desirable for all types of preparations, but it is logical for quantitation of estrogen and progesterone receptors, infiltrating immunoregulatory populations in tumors, and many other applications.

Automation↗
PubMed1989

Fibrous tumors of bone.

Benign and malignant fibrous tumors of bone are some of the most common tumors encountered by the orthopedic surgeon. Fibrous dysplasia, fibrous cortical defect, non-ossifying fibroma, benign fibrous histiocytoma and osteofibrous dysplasia are benign tumors best treated conservatively or by intralesional/marginal excision. Desmoplastic fibromas are locally aggressive and require a wide margin for surgical cure. Malignant fibrous histiocytoma and fibrosarcoma of bone are malignant bone tumors and must be treated with wide/radical margins and for malignant fibrous histiocytoma adjunctive chemotherapy.

Bone Neoplasms↗
PubMed1989

Bone quality. Roentgenographic versus histologic assessment of hip bone structure.

Bone quality is an accepted criterion for determining fixation options for total hip arthroplasty (THA). Eighty patients with 95 uncemented THAs were evaluated by comparing preoperative roentgenographic assessment with histologic evaluation of bone biopsy specimens obtained from the ipsilateral iliac crest. Roentgenographic analysis of bone quality was performed using the Singh and Engh indices. Histologic evaluation employed a quantitative analysis of static and dynamic parameters of bone turnover on undecalcified sections. Extensive statistical analysis comparing roentgenographic with histologic parameters of bone quality showed: (1) no relationship of the two roentgenographic indices to trabecular bone volume and most other histologic parameters and (2) a high incidence of bone abnormalities. Bone quality is an imprecise term and is inadequately measured by these roentgenographic indices. Histologic measurement offers a more precise means of analyzing the relationship of the bone environment to the performance of the THA.

Biopsy↗
PubMed1989

A diagnostic algorithm for osteonecrosis of the femoral head.

For patients considered at risk for osteonecrosis (ON) of the femoral head, an algorithm for the efficient and appropriate use of diagnostic tests can be developed. Such an algorithm requires a clear idea of the evolution of the disease process and an understanding of the limitations of each of the modalities by which the disease process can be identified. The role of each of the diagnostic tests available for the diagnosis of ON and the results of prospective evaluations to assess their sensitivity, specificity, and predictive values are reviewed. No single diagnostic test is 100% accurate in the diagnosis of the disease. Thus, one must consider an algorithm that accounts for the variable nature of the disease presentation. The goal of such an algorithm is the accurate identification and staging of the disease. For disease not roentgenographically apparent, an approach using magnetic resonance imaging and bone scanning is recommended. For disease that is apparent roentgenographically, tomography is used to define the extent of the disease and the presence or absence of subchondral fracture. The accuracy of diagnosis is critical to understanding the role of the various treatment modalities prescribed for ON. For this purpose, it is necessary to reach a consensus as to what constitutes a successful outcome of treatment. Once diagnosis of the disease is accepted, clinical success of treatment outcomes should be reported in three ways: by a standard hip rating system, by ability to prevent roentgenographic deterioration, and by survival of the femoral head (the absence of further treatment intervention).(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMed1989

Multimodality approach to osteonecrosis of the femoral head.

Treatment of osteonecrosis of the femoral head appears to be effective when the disease is identified and treated early. Forty-one patients were evaluated with prospective laboratory assessment, anteroposterior and frog-lateral roentgenograms of both hips, intraosseous pressure measurements (IOP), magnetic resonance imaging (MRI), and 99mTc methylene diphosphonate planar and single-photon emission computerized tomographic (SPECT) bone imaging. Pathologic specimens were obtained in most patients. Preradiographic disease was identified in 26 hips and 11 of these were asymptomatic. Fifteen clinically symptomatic hips had normal plain roentgenograms, but abnormal protocol studies. Evaluation of sensitivity, specificity, and predictive value (positive and negative), respectively, in diagnosing osteonecrosis of the femoral head revealed the following percentages: 83%, 83%, 96%, and 48% for planar bone scanning; 91%, 78%, 94%, and 70% for SPECT; 87%, 83%, 96%, and 55% for MRI; 80%, 60%, 95%, and 25% for IOP; and 88%, 100%, 100%, and 25% for core biopsy. (There were few true negatives, thus specificity values are approximations.) The identification of preradiographic stages is possible, but difficult. MRI appears appealing at present, particularly in identifying disease in asymptomatic hips. However, there is no definitive method for noninvasive diagnosis. Pathologic confirmation in early stages is difficult.

Adolescent↗
PubMed1988

Riedel's thyroiditis.

Riedel's thyroiditis is a rare chronic inflammatory disease of the thyroid gland first recognized by Bernhard Riedel in 1893. In order to clarify the clinical and pathologic features of this rare disorder, a recent case of Riedel's thyroiditis is presented, 6 additional cases from the surgical pathology files of the Cleveland Clinic Foundation are reported, and the 178 cases previously reported in the English literature are reviewed. The mean age at presentation has been 47.8 years, and 83% of patients have been female. Sixty-four percent were euthyroid, 32% hypothyroid, and 4% hyperthyroid. Antithyroid antibodies have been detected in 16 of the 25 patients tested. Since 1960, 34% of the published cases of Riedel's thyroiditis have reported the development of multifocal fibrosis. Immunohistologic study of the inflammatory infiltrate reveals a mixed population of B- and T-cells. Comparison with the infiltrate in Hashimoto's thyroiditis shows similar proportions of CD4- and CD8-positive lymphocytes. The relationship and origin of multifocal fibrosing lesions has not been defined, but an immunologic origin seems most likely. The finding of antithyroid antibodies in 67% of patients supports an autoimmune mechanism of injury.

Adult↗
PubMed1987

Gorham's syndrome: a case report and review of the literature.

Gorham's syndrome is a rare disorder involving a proliferation of vascular channels associated with extensive loss of bony matrix. A case report is presented with a review of the 97 previously reported cases. The age of patients at presentation has ranged from less than one to 75 years (mean: 27 years). Sixty-four percent have been men. Fifty-seven percent have had a history of prior trauma. Laboratory values for systemic measures have usually been normal. The disease usually arrests spontaneously, but this is unpredictable. Sixteen patients (16 percent) have died of the disorder, with 10 deaths due to chest wall involvement, three to spinal cord transection, two to sepsis, and one to asphyxia and aspiration. Although the mechanism of bone loss is unknown, osteoclasts were focally increased in the case described herein. Further information and investigation are needed to better understand this unusual disorder.

Adult↗
PubMed1987

Gastric antral vascular ectasia. A histologic and morphometric study of "the watermelon stomach".

Gastric antral vascular ectasia (GAVE) is an uncommon but important cause of gastrointestinal blood loss and iron deficiency anemia that is characterized by a distinctive endoscopic appearance consisting of parallel erythematous folds traversing the gastric antrum. In order to clarify the histologic features of this lesion, nine antral biopsy specimens from seven patients with the clinical and endoscopic diagnosis of GAVE were reviewed and compared with specimens from normal controls and patients with other common antral lesions. Specimens obtained using standard endoscopic biopsy forceps were evaluated for mucosal vascularity, presence of intravascular fibrin thrombi, and the following histologic changes: mucosal inflammation, fibromuscular hyperplasia of lamina propria, epithelial regeneration, and mucosal architectural distortion. Mucosal vascularity was determined by counting the absolute number of vascular lumina per slide, measuring the mean cross-sectional area of each vessel lumen, and determining the percentage of each specimen occupied by vessels. Histologic changes were graded as absent to minimal, moderate, or marked. Significant differences (p less than 0.05) between GAVE and control groups were mean vessel cross-sectional area, percentage of area occupied by vessels, presence of intravascular fibrin thrombi, and fibromuscular hyperplasia. GAVE appears to demonstrate sufficiently distinctive histopathologic features to allow its recognition in antral biopsy specimens obtained by endoscopy.

Adult↗
PubMed1987

Intraneural lipoma of the sciatic nerve.

A large, well-encapsulated intraneural lipoma occurred within the sciatic nerve of a 34-year-old woman. In a review of the literature, significant differences were noted between the well-encapsulated and the diffusely infiltrative lipofibromatous hamartoma types of intraneural lipomas. The average age at the time of appearance of the well-encapsulated type is 45 years, with female predominance, while the infiltrative type arises in a younger age group (average age, eight years) with no sexual predominance. To avoid a recurrence, total excision is recommended in cases of the well-encapsulated type. Attempts to excise the diffusely infiltrative type are likely to fail.

Adult↗
PubMed1986

Periosteal Ewing's sarcoma.

Ewing's sarcoma is a small cell malignant tumor that usually arises in the medullary cavity of bone. Less frequently, it originates in soft tissue and may secondarily invade underlying bone. The origin of Ewing's sarcoma in a periosteal location without extension into either the bone or adjacent soft tissue has not been clearly documented. Other malignant tumors of bone (e.g., osteosarcoma) appear to have a somewhat better prognosis when confined between periosteum and bone. The case of a patient with a periosteal Ewing's sarcoma who received a radical excision and postoperative chemotherapy and who is without evidence of disease with over 2 years follow-up is reported.

Adolescent↗