PubMed Health⌕ Search

Biomedical subjects

L J Layfield

Publications and source records attributed to L J Layfield.

At least 109 records · Page 6Linked to original sources
PubMed1991

Diagnosis of salivary gland tumors by fine-needle aspiration cytology: a review of clinical utility and pitfalls.

Fine-needle aspiration cytology has become a frequently used technique for the diagnosis of neoplasms of the head and neck. While the method has a high sensitivity and specificity for the diagnosis of salivary gland lesions, important pitfalls for the cytologic diagnosis of these lesions exist. This paper discusses the diagnostic pitfalls and investigates strategies for the evaluation of salivary gland masses.

Biopsy, Needle↗
PubMed1991

Fine-needle aspiration cytology and the diagnosis of neoplasms in the pediatric age group.

Sixty-six aspirates obtained from 63 pediatric patients clinically suspected of having small cell malignancies were studied by a variety of techniques to determine the accuracy and utility of fine-needle aspiration (FNA) in the diagnosis of small round-cell neoplasms (SRCN) of childhood. FNA correctly identified all 47 SRCNs as malignant and gave a correct specific diagnosis in 81% of the cases. No false-positive diagnoses of malignancy occurred in this series. Electron microscopy, immunohistochemistry, and cell culture performed on FNA material were found to be useful aids in the differential diagnosis of these tumors. The cytologic appearances and differential diagnoses of these neoplasms are discussed.

Adolescent↗
PubMed1991

Fine-needle aspiration cytology accuracy with palpable gynecologic neoplasms.

From 1984 to 1988, 62 fine-needle aspirations (FNA) were performed on palpable lesions in 59 gynecologic oncology patients at the UCLA Medical Center. Sites of aspiration included abdomen, cervix, vagina, superficial lymph nodes, and pelvic masses. Confirmatory open biopsy (41) or adequate clinical follow-up (17) was obtained in 55 patients (58 aspirates). FNA correctly established the diagnosis of malignancy in 19 of 26 (73%) biopsied patients. The predictive value for a positive test was 100%, and the predictive value for a negative test was 82%. Initial surgical biopsy had been incorrectly benign in 4 of these patients who were shown subsequently to have malignant tumors by FNA and clinical findings. In 7 patients, FNA failed to diagnose the malignancy found by open biopsy. Two of the false-negative FNAs were insufficient and five were in masses where palpation was inadequate. In 17 patients who were followed clinically without open biopsy, FNA correctly predicted the subsequent clinical course in 15 (88%). There were no false-positive FNA diagnoses obtained when cytologic results were correlated with both clinical outcome and surgical biopsy. Aspiration cytology has a specificity of 100% and a sensitivity of 65%. A negative FNA obtained from a clinically suspicious lesion should be followed by a repeat aspiration or surgical biopsy.

Abdominal Neoplasms↗
PubMed1991

Desmoplastic small cell tumors of the peritoneum coexpressing mesenchymal and epithelial markers.

Desmoplastic small cell tumors arising diffusely within the abdomen and lacking an apparent organ of origin are rare. Most previously reported cases occurred in children, but young adult patients also have been described. Light microscopic examination shows the tumors to be composed of nests of small cells surrounded by an abundant desmoplastic stroma. Immunohistochemical findings reveal multidirectional differentiation with coexpression of cytokeratin, milk fat globule, neuron-specific enolase, Leu-7, desmin, and vimentin. Electron microscopic examination demonstrates paranuclear condensations of intermediate filaments. The authors describe two patients who died of their disease, despite aggressive chemotherapy and surgical intervention.

Adolescent↗
PubMed1991

Meckel cave lesions: percutaneous fine-needle-aspiration biopsy cytology.

The authors describe the novel combination of two traditional methods to facilitate diagnosis of Meckel cave lesions, which may otherwise require craniotomy to obtain adequate tissue samples. Fine-needle-aspiration biopsy cytology was performed on tissue obtained with a percutaneous approach via the foramen ovale with use of fluoroscopic guidance and intravenous analgesia during an outpatient procedure. This new application of fine-needle-aspiration biopsy cytology results in decreased patient morbidity and significant cost reduction.

Adult↗
PubMed1991

Photodynamic therapy using rhodamine-123 as a new laser dye: biodistribution, metabolism and histology in New Zealand rabbits.

Rhodamine-123 (Rh-123) has been tested recently as a new laser dye for photodynamic therapy of human tumors in vitro and in vivo. Prior to initiation of clinical studies of this technique, we evaluated the biodistribution, metabolism, and pathological changes of Rh-123 in rabbits after systemic, repetitive injections of the dye in escalating doses. At doses between 0.1 to 1 mg/kg of Rh-123 injected intramuscularly (IM) daily for 5 days, no local or systemic toxicity was observed during the 4 weeks of follow-up. The peak concentrations of Rh-123 in micrograms/g of tissue was distributed as follows: kidney (3.24) greater than heart (2.24) greater than spleen (1.77) greater than lung (0.61) greater than liver (0.38) greater than skin (0.30) greater than skeletal muscle (0.17) greater than genitals (0.13) greater than brain (0.04). The elimination of Rh-123 was very rapid, with the dye falling to 2.7% of peak concentration at 72 hours in the kidneys, and to undetectable levels at 240 hours postinjection in all organs, except the skin, which retained 3% of the peak level at 240 hours. The low toxicity and rapid metabolism of Rh-123 in this preclinical model suggests that the dye and Argon laser may represent an effective combination for treatment of superficial malignancies.

Animals↗
PubMed1991

Nd: YAG interstitial laser phototherapy guided by magnetic resonance imaging in an ex vivo model: dosimetry of laser-MR-tissue interaction.

Interstitial laser phototherapy (ILP) is a promising technique in which laser energy is delivered percutaneously to various depths of tumors. This technique will become clinically useful only when efficient, sensitive, and noninvasive monitoring systems are developed. In this study, the spatial distribution of ILP in bovine liver tissue, induced by a Nd: YAG laser with an interstitial sapphire-frosted contact probe, was evaluated by magnetic resonance imaging (MRI). Tissue was exposed to three energy densities of the Nd:YAG laser by a reproducible method of dosimetry. Thermal profiles were measured with a probe inserted 5 mm from the laser tip. T1-weighted magnetic resonance images were taken after the laser exposure. Tissue specimens were then evaluated for standard quantification of laser-induced damages. A linear correlation between the level of laser energy, induced temperature change, lesion size on T1 magnetic resonance image, and volume of histological damage was observed. Further improvement of this technique of dosimetry in an in vivo model should allow the development of software for MRI which will correlate the above parameters and render this technique of ILP clinically useful.

Animals↗
PubMed1991

Morphometric analysis of borderline atypia in prostatic aspiration biopsy specimens.

In a prior study of 411 fine needle aspirates of the prostate (FNAPs), we identified a subset of 50 (12%) aspirates in which the findings were designated cytologically atypical. These equivocal cases formed a heterogeneous group composed of both histologically benign and malignant proliferations in which cutting needle biopsy was necessary to further delineate the nature of the abnormality. In an attempt to define quantitative and morphologic criteria for the separation of these proliferations into benign and malignant categories and to reduce the need for diagnostic cutting needle biopsies, we performed a cytomorphometric analysis of smears from 12 FNAPs (6 histologically proven benign and 6 histologically proven malignant) with equivocal cytologic atypia. We were unable to define any cytomorphometric criteria that accurately subdivided these cases into benign and malignant categories.

Adenocarcinoma↗
PubMed1991

Cytologic criteria used to diagnose adenocarcinoma in pleural effusions.

A stepwise logistic regression analysis was employed to evaluate the usefulness of the following criteria to distinguish adenocarcinoma in pleural effusion from benign pleural effusion: increased size of nucleus, increased nuclear to cytoplasmic ratio, irregular nuclear borders, sharply defined cytoplasmic boundaries, large nucleoli, aggregates with variable size nuclei, aggregates with nuclear overlap, irregular noncentral vacuoles, aggregates with nuclear molding, multinucleation, three-dimensional aggregates, aggregates with large cytoplasmic vacuoles, atypical mitoses, nuclear vacuoles, homogeneous cytoplasm, aggregates with associated lymphocytes and neutrophils, and uniform size aggregates. A total of 223 patients with benign pleural effusion cases and 221 patients with adenocarcinoma in their pleural effusion were scored as to the presence or absence of the above criteria. The resulting data were subjected to a stepwise logistic regression analysis that chose increased nuclear/cytoplasmic ratio, irregular nuclear borders, large nucleoli, sharply defined cytoplasmic boundaries, and three-dimensional aggregates as the best criteria to differentiate adenocarcinoma in pleural effusion from benign pleural effusion. When used together, these five features had a sensitivity of 94% and a specificity of 93% for predicting adenocarcinoma.

Adenocarcinoma↗
PubMed1991

Pleomorphic fibroma of skin. A case report and immunohistochemical study.

An immunohistochemical study of a clinically benin but cytologically atypical mesenchymal lesion of the skin is presented. This lesion has been previously reported as pleomorphic fibroma and was shown to follow a benign course with a potential for local recurrence. These lesions contain occasional markedly atypical enlarged spindle cells with anaplastic-appearing nuclei. Nonmirror image mitotic figures may be present. Histogenesis of this neoplasm remains controversial with a fibroblastic origin being favored by previous authors. Our immunohistochemical findings would support this conclusion.

Adult↗
PubMed1990

Interstitial laser phototherapy assisted by magnetic resonance imaging: a new technique for monitoring laser-tissue interaction.

The rapid technological advances of magnetic resonance imaging, laser fiberoptics, and compatible probes may allow treatment of deep and sometimes surgically unreachable tumors of the head and neck with minimal morbidity through interstitial laser phototherapy. In this study, a new application of magnetic resonance imaging was developed to monitor and quantify laser-induced tissue damages. Pig skin was exposed to increased levels of argon laser (514.5 nm) at energy densities between 62.5 and 375 J/cm2 as determined by an accurate and reproducible method of dosimetry. Thermal profiles were recorded using an infrared sensor and T1- and T2-weighted magnetic resonance images were taken; afterward, biopsies were performed to quantitate the level of tissue damage. Our results demonstrate that above a certain threshold of laser energy, the magnetic resonance imaging findings are temperature dependent. Appropriate development of a scale matching laser energies, temperature profiles, T1- and T2-weighted magnetic resonance images, and histological quantitation of tissue destruction will allow us to optimize the three-dimensional control and monitoring of laser-tissue interactions.

Animals↗
PubMed1990

Flexible Nd:YAG laser palliation of obstructive tracheal metastatic malignancies.

Flexible Nd:YAG endoscopic laser surgery may become an effective new modality for palliation in patients with obstructive endotracheal metastatic malignancies. We report the results of the treatment of two patients with severely obstructing intraluminal tracheal metastatic melanoma and medullary thyroid carcinoma, using the neodymium-YAG laser via the flexible fiberoptic bronchoscope. Both patients complained of significant dyspnea, orthopnea, cough, and hemoptysis and were not candidates for rigid bronchoscopy because of underlying medical contraindications and anatomical problems. Multiple treatment sessions were used with treatment intervals of 1 to 2 weeks. All treatments were performed in the operating room under sedation, without intubation, with topical lidocaine and standard superior laryngeal nerve block. Successful relief of airway obstruction with complete regression of the endotracheal masses was achieved and no recurrences were seen after 9 months' follow-up. Flexible Nd:YAG laser bronchoscopy offered an alternative for the relief of obstructing endotracheal or bronchial malignancies in patients in whom the rigid bronchoscope could not be passed. it seemed to prolong survival in selected cases, and provided definite improvement in quality of life.

Aged↗
PubMed1990

Magnetic resonance imaging of metastatic cervical adenopathy.

Detecting cervical adenopathy is critical in the management of carcinomas in head and neck. CT scanning remains a very effective modality in defining adenopathy. T1-weighted MRI scans are comparable to CT in detecting lymph nodes. T2-weighted images are less useful as the lymph nodes tend to have long T2 relaxation times similar to the surrounding fat. MR has not proved to be useful in detecting carcinoma in non-enlarged cervical nodes. The morphologic criteria developed for metastatic nodes with CT are appropriate with MRI (size, shape, signal, extracapsular spread). Gadolinium is sometimes useful in defining central necrosis in metastatic squamous cell adenopathy.

Carcinoma, Squamous Cell↗
PubMed1990

Interventional magnetic resonance imaging in the head and neck.

Interventional MRI is clearly in its early stages of development. While the value of MR-guided aspiration cytology and MR evaluation of deep electrode implantation in the brain has already been confirmed with human clinical studies, the future of MR-guided interstitial laser therapy remains to be proven. Despite this, as we look ahead into the 1990s and the millennium, it is possible to imagine dedicated MR laser therapy units for combined radiological and surgical outpatient approaches in what may become the operating rooms of the 21st century.

Biopsy, Needle↗
PubMed1989

Relation between DNA ploidy and the clinical behavior of phyllodes tumors.

We studied the DNA histograms obtained by flow cytometry from a series of six giant fibroadenomas and ten phyllodes tumors to determine if the analysis of DNA ploidy would help to predict clinical behavior. We were unable to document any relation between ploidy and histologic appearance, recurrence, metastasis, lesion size, or patient age. DNA aneuploid stem cell lines were seen in 75% of histologically benign phyllodes tumors, 50% of histologically malignant phyllodes tumors, and approximately 33% of giant fibroadenomas.

Adenoma↗
PubMed1989

Sources of diagnostic error in fine needle aspiration of the thyroid.

Smears obtained from 795 patients with suspicious thyroid nodules by fine needle aspiration (FNA) of the thyroid gland were seen over a 5-year period at the UCLA Center for the Health Sciences. From 72 patients who underwent subsequent surgical excision of their nodules, inadequate or discrepant FNA diagnoses were noticed in 20 cases (27.8%). These errors could be attributed to inadequate material for diagnosis (n = 6), sampling errors (n = 2), and cytodiagnostic errors (n = 12). If the diagnosis of follicular neoplasm was treated as indeterminate for malignancy, the overall efficiency of FNA was 88.9%. All false-negative diagnoses were related to procedure (i.e., inadequate smears or missed sampling of the lesion). The frequency of inadequate smears, in turn, was strongly related to the type of physician performing the aspiration. The frequency was highest among community-based clinicians (32.4%) and lowest among hospital-based cytopathologists (6.4%). With adequate sampling, the finding of 100% sensitivity in the diagnosis of malignant neoplasms by FNA cytology reaffirms its role as the procedure of choice in the initial screening of thyroid nodules.

Adolescent↗
PubMed1989

Clarifying the role of fine-needle aspiration cytologic evaluation and frozen section examination in the operative management of thyroid cancer.

The final histologic diagnoses of 486 patients who underwent thyroidectomy at UCLA Medical Center from March 1975 to August 1988 were reviewed. There were 146 patients with a diagnosis of thyroid malignant neoplasm. All patients who had preoperative fine-needle aspiration cytologic evaluation, intraoperative frozen section analysis, or both were included in the present study. Carcinoma was diagnosed by frozen section in 87 (69%) of 126 cases. Frozen section analysis was incorrect in 39 (31%) of 126 cases. Fine-needle aspiration was performed in 62 patients. A malignant neoplasm was identified by fine-needle preoperative fine-needle aspiration and intraoperative frozen section analysis, and carcinoma was detected by both methods in 32 (57%) of 56 cases. Fine-needle aspiration cytologic evaluation is extremely valuable in the diagnosis of thyroid cancer and is at least as accurate as frozen section analysis with less morbidity and expense. When fine-needle aspiration demonstrates malignant neoplasm, thyroid resection may be planned with confidence.

Adolescent↗