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Biomedical subjects

S Sheth

Publications and source records attributed to S Sheth.

At least 73 records · Page 4Linked to original sources
PubMed1990

From the archives of the AFIP. Malignant germ cell tumors of the ovary: radiologic-pathologic correlation.

Malignant germ cell tumors are the most common malignant ovarian neoplasms in girls and young women. The most well known of these neoplasms are dysgerminoma, immature teratoma, endodermal sinus tumor, and a mixture of two or more of these elements. All malignant germ cell tumors, especially immature teratoma, can be associated with mature (benign) teratoma. These tumors are generally large and have a complex but predominantly solid appearance on cross-sectional images. Elevated serum alpha-fetoprotein and human chorionic gonadotropin levels can help establish the diagnosis. Cystic areas of calcifications suggestive of mature teratoma do not exclude a co-existing malignant neoplasm.

Female↗
PubMed1990

Bright echogenic foci in early prostatic carcinoma: sonographic and pathologic correlation.

One hundred sixty patients with biopsy-proved clinical stage A or B prostatic carcinoma were examined with high-resolution transrectal ultrasonography prior to radical prostatectomy. All tumors showed either a hypoechoic or isoechoic echo pattern. However, 11 patients demonstrated evidence of focal bright echogenic areas at the periphery or within the center of a hypoechoic tumor. Coarse echogenic foci seen in seven patients corresponded pathologically to calcified corpora amylacea in benign tumors of the prostate gland either at the edge of the tumor or scattered throughout the tumor. Seven patients showed a fine, stippled echogenic pattern within the lesion. On a pathologic level, this pattern represented high-grade tumors with extensive central comedonecrosis and calcifications in five patients and an unusual deposit of small intraluminal crystalloid deposits in two patients. Combinations of echo patterns were observed in three patients. This study demonstrates that echogenic foci can be seen within predominantly hypoechoic tumor nodules. Coarse bright echoes, usually at the periphery of the tumor, suggest calcifications in benign prostate glands. Tumor calcifications and intraluminal prostatic crystalloid deposits were located more centrally and had a finer stippled sonographic appearance.

Adenocarcinoma↗
PubMed1990

Pelvic masses: aspiration biopsy with transrectal US guidance.

Biplanar, transrectal ultrasound guidance was used in the transrectal aspiration of two pelvic abscesses, one recurrent tumor, and one sterile, nonmalignant fluid collection. This method provides an alternative path that allows precise localization for aspiration biopsy of pelvic masses.

Abscess↗
PubMed1990

Carcinoma of the prostate: value of transrectal sonography in detecting extension into the neurovascular bundle.

Detection of involvement of the neurovascular bundles (NVB) by tumor is important in deciding whether sexual function can be preserved in patients undergoing radical prostatectomy for prostatic cancer. The nerve branches innervating the corpora cavernosa have a rather constant association with the capsular arteries and veins of the prostate, forming the periprostatic neurovascular bundle, which can be identified intraoperatively and spared during radical surgery, thus preserving potency. We examined 160 patients with biopsy-proved clinical stage A or B adenocarcinoma with transrectal sonography before radical prostatectomy to determine how useful the procedure is for predicting tumor extension into the NVB. Correlation with pathologic serial sections was obtained in each patient. The sonograms depicted the NVB on both sides in 77 patients (50%), on the right side only in 13 (8%), and on the left side only in 36 patients (23%). In 29 patients (19%) neither neurovascular bundle could be identified on the sonograms. Ninety-one tumors in this series showed evidence of extraglandular spread pathologically, which was posterolateral or into the NVB in 70 tumors involving 82 hemispheres. Using transrectal sonography, we correctly identified invasion of the NVB in 54 cases and missed it in 28 cases. NVB invasion was predicted incorrectly with transrectal sonography in 51 cases; absence of involvement of the NVB was correctly predicted in 177 hemispheres. The sensitivity of sonography for predicting invasion of the NVB was 66%, with a specificity of 78% and an accuracy of 75%. Positive predictive values and negative predictive values were 51% and 86%, respectively. We conclude that transrectal sonography currently suffers from lack of sufficient spatial resolution to detect accurately invasion of the NVB.

Adenocarcinoma↗
PubMed1990

Cystic lesions of the prostate gland. A sonographic--pathologic correlation.

277 patients underwent biplane transrectal ultrasonography. Twenty-two patients (7.9%) showed evidence of one or more intraprostatic cystic lesions. Histologic correlation was available with total prostatectomy specimens in six patients and surgical drainage in two patients. Sonographically, 11 patients showed one, 6 patients two, and 5 patients three or more intraprostatic cystic lesions. The size of the lesions ranged from 2 to 30 mm, and the majority of lesions were located within the central portion of the gland or at the junction of central and peripheral regions of the gland. Histologically, among the eight pathologically confirmed patients the lesions corresponded to cystically dilated, epitheliallined prostatic glands, a reepithelialized cyst related to previous biopsy, a dilated utricle, and two intraprostatic abscesses. The cystic lesions in our series were not associated with carcinoma of the prostate, but represented either a growth phenomenon related to the presence of benign prostatic hypertrophy, inflammatory conditions (abscesses), or anatomical variants (utricle).

Abscess↗
PubMed1989

Evaluation of transrectal ultrasound in the early detection of prostate cancer.

To determine the ability of transrectal ultrasound to detect early localized prostate cancer, unsuspected (nonpalpable) cancer in the contralateral lobe of patients undergoing radical prostatectomy for clinically localized disease was evaluated. A total of 59 patients with palpable prostate cancer clinically confined to 1 lobe underwent transrectal ultrasound before radical prostatectomy and step-sectioning of the radical prostatectomy specimen. Transrectal ultrasound was performed with 5 or 7 MHz. real-time transrectal units. Pathological findings in these 59 cases revealed no tumor in the contralateral lobe in 34 (58%) and the presence of unsuspected tumor in 25 (42%). Transrectal ultrasound detected 13 of 25 unsuspected cancers for a sensitivity of 52%. Of 34 patients with no contralateral lobe lesion transrectal ultrasound was correct in 23 for a specificity of 68%. The positive and negative predictive values for transrectal ultrasound in this study group were 54 and 66%, respectively. There was no significant difference in the pathological size of the clinically suspected and clinically unsuspected cancers as measured by average largest dimension, and transrectal ultrasound sensitivity did not correlate with the size of the cancer. Based on careful sonopathological analysis, transrectal ultrasound may not be a good method to detect clinically unsuspected prostate cancer and the false positive rate would appear to be high.

Humans↗
PubMed1989

Parasternal sonography of the internal mammary vessels: technique, normal anatomy, and lymphadenopathy.

Metastasis to the internal mammary lymph nodes adversely affects the disease-free interval and long-term survival in women with breast carcinoma. Since staging of disease in this lymphatic chain is rarely performed at the time of definitive surgical treatment, noninvasive methods have been advocated. The authors present their preliminary experience with a sonographic technique for evaluating the internal mammary lymph nodes, artery, and vein. Longitudinal and transverse images of the first through fourth parasternal rib interspaces were acquired with a 5.0- or 7.5-MHz linear-array real-time system. The method was evaluated prospectively in 36 control subjects and in seven patients (six with metastatic breast cancer and one with lymphocytic lymphoma) who had enlarged internal mammary lymph nodes at thoracic computed tomography (CT). The longitudinal scans routinely demonstrated the internal mammary vessels in the upper interspaces. Lymphatic structures were not identified in the control group. In contrast, sonographic findings corresponding to the CT findings of lymphadenopathy were present in all seven patients. The authors believe that parasternal sonography is a promising technique that merits further study.

Adult↗
PubMed1988

Prenatal diagnosis of sacrococcygeal teratoma: sonographic-pathologic correlation.

The prenatal sonograms of 15 fetuses with sacrococcygeal teratoma were reviewed to determine the sonographic appearance and the role of sonography in the obstetric management. Each tumor appeared as a large mass arising from the fetal rump. The teratomas exhibited three sonographic patterns: nine were mixtures of cystic and solid components in equal proportions, four were predominantly solid with a few scattered anechoic areas, and two were unilocular cystic masses. Calcifications were detected in six cases. There was no correlation between the sonographic appearance and the presence of immature or malignant components. Ultrasonography allowed visualization of an intraabdominal component in six cases and assessment of findings that were of prognostic importance. Prenatal detection and size determination of the external component can play an important role in planning obstetric management because fetuses with a large tumor should be delivered by cesarean section to avoid dystocia and catastrophic hemorrhage during delivery.

Female↗
PubMed1988

Renal involvement in AIDS: sonographic-pathologic correlation.

Renal sonography was performed in 36 patients with clinical and/or laboratory evidence of AIDS, usually because of deteriorating renal function. In 15 patients, histopathologic specimens were reviewed to characterize renal pathologic changes underlying the sonographic findings. Sonographic evaluation included determination of renal size and cortical echogenicity according to a standard grading system. Pathologic specimens were evaluated for tubular and glomerular abnormalities. Sonography showed either normal-sized or enlarged kidneys with grade I cortical echogenicity in 13 patients (36%), grade II in three patients (8%), and grade III in five patients (14%). Fifteen patients (42%) had normal renal echogenicity. In addition to focal segmental glomerulosclerosis the pathologic examination showed different degrees of tubular abnormalities. Striking, irregularly dilated, infolded tubules with flattened epithelium and intratubular deposits of proteinaceous material, and sometimes cystlike formation involving the medulla and cortex, were seen in two patients with grade III kidneys, and mild dilatation of the tubules was seen in four patients with grade I disease. Moderate tubular dilatation was observed in one patient with grade I disease. No significant tubular abnormality was seen in one patient with grade I disease or in seven patients with normal renal echogenicity. Although glomerular changes contribute to the increase in renal echogenicity, we postulate that the main factors responsible for the increased echogenicity in AIDS nephropathy are the striking tubular abnormalities seen in these patients.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The variable sonographic appearances of ovarian teratomas: correlation with CT.

To better understand how the internal composition of ovarian teratomas influences their sonographic features, we compared their sonographic and CT appearances in 23 cases. Sixteen lesions had a mixed echo texture, with hypoechoic as well as echogenic components; two were anechoic and five were entirely echogenic. Correlation with the CT images showed that the fat present in most teratomas had variable sonographic appearances. Pure sebum was anechoic or hypoechoic, but fat intermixed with hair strands was echogenic and often attenuated the sound beam because of the numerous tissue interfaces created within the mass. The hypoechoic component of the teratoma corresponded, on CT, to low-attenuation fat in 12 tumors and to fluid in five. Most teratomas contained a dermoid plug, a protuberance arising from the tumor wall and containing hair follicles and often fragments of bone or teeth. On sonography, all dermoid plugs were seen as an echogenic mass, often associated with distal acoustic shadowing and protruding into the hypoechoic portion of the teratoma. When the dermoid plug was large and occupied most of the tumor, the entire teratoma appeared echogenic, with no discernible anechoic component. We found that three factors greatly affected the sonographic appearance of ovarian teratomas: the size of the dermoid plug, the presence and location of calcified elements, and the histologic composition of the fatty component.

Adult↗
PubMed1987

Cystic hygromas in children: sonographic-pathologic correlation.

The sonographic findings in eight children with surgically proved cystic hygroma were reviewed and correlated with the pathologic specimens. Six tumors occurred in the neck, one occurred in the axilla, and one involved the soft tissues of the thigh, scrotum, and pelvis. A cystic hygroma characteristically appears as a multiloculated cystic mass with septa of variable thickness that contain solid components arising from the cyst wall or the septa. Correlation of the sonogram with the pathologic specimen demonstrated that the echogenic component corresponded to a cluster of abnormal lymphatic channels, too small to be resolved with ultrasound. Large lesions had ill-defined boundaries, with cystic components dissecting between normal tissue planes. Sonographically, one can usually differentiate these tumors from other cervical masses, especially soft-tissue hemangiomas. Sonography is also helpful in determining the extent of the lesion before surgery and in assessing postoperative complications and recurrences.

Axilla↗
PubMed1987

A paucity of thalassemia trait in Italian men with myocardial infarction.

We studied the prevalence of thalassemia trait in a group of Italian male myocardial infarction (MI) patients and an ethnically similar group of men admitted for other conditions. Italian men constituted approximately 13% of each group. Of 359 Italian men with a MI, only 2 had thalassemia trait. In contrast, of 330 adult Italian males in the non-MI group (mean age 59.6 years), 11 had thalassemia trait. Because the frequency of thalassemia trait was significantly (p less than 0.01) lower in the myocardial infarct group, we conclude that thalassemia trait may be a protective attribute as regards MI. A prospective study of individuals with thalassemia minor is indicated to elucidate the mechanism for the observed protective effect and to determine what risk factors may offset the protective effect in those that do experience MI.

Heterozygote↗
PubMed1985

A modified double antibody sandwich enzyme-linked immunosorbent assay for measurement of alpha-1-antitrypsin in biologic fluids.

Alpha-1-antitrypsin (alpha 1AT) is the major protease inhibitor in human serum, and plays an important role protecting tissues from potentially harmful enzymes released during inflammatory reactions. Proteolytic enzymes such as leukocyte elastase are usually released and inactivated locally at the site of inflammation, so there has been much recent interest in measuring local alpha 1AT concentrations in biologic fluids. In this study, we developed a modified double antibody sandwich enzyme-linked immunosorbent assay (ELISA) and used it to measure alpha 1AT concentrations in several biologic fluids. The assay was sensitive to as little as 20 ng/ml of alpha 1AT. Serum concentrations measured by the ELISA correlated well with levels determined by radial immunodiffusion (RID) and the ELISA was far more sensitive than RID. In synovial fluid, higher concentrations determined by the ELISA compared with RID probably reflect interference of diffusion of alpha 1AT in the RID gel by hyaluronic acid and protease-inhibitor complexes. Synovial fluid did not interfere with the detection of added alpha 1AT by ELISA, but it did reduce the amount detected by RID by about 30% in 2 fluids. In saliva, alpha 1AT concentrations of less than 1 microgram/ml were easily quantified. Bronchoalveolar lavage fluids have been extensively studied because of the important role of alpha 1AT in pulmonary inflammatory processes. We found concentrations of 1-3 micrograms/ml in most samples with our assay. These levels were comparable to those previously reported with assays that required up to 50-fold concentration of the fluid. Neither saliva nor bronchoalveolar fluid significantly interfered with detection by ELISA of added alpha 1AT. This modified double antibody sandwich ELISA may have broad applications for studies of the role of alpha 1AT in health and disease.

Body Fluids↗
PubMed1985

Policies and attitudes toward the pregnant radiology resident.

To evaluate attitudes and policies toward pregnant radiology residents, a questionnaire was sent to the chiefs of radiology residency programs across the country. A return rate of 76.4% and a response rate of 75.4% were achieved. A large majority of the respondents indicated that schedule changes would be made to avoid excessive exposure of a pregnant resident to radiation. The accommodations they suggest are reviewed, and suggestions are made that would help alleviate some of the stress and conflicts that invariably arise when a resident becomes pregnant.

Attitude↗