Video-assisted thoracoscopic surgery for intrathoracic extramedullary hematopoiesis

Extramedullary hematopoiesis is a rare cause of an intrathoracic mass in individuals with hemolytic disorders. It can be clinically confused with other tumors of the mediastinum. While radiologic studies often demonstrate findings suggesting intrathoracic extramedullary hematopoiesis, histology is usually required for diagnostic purposes. Thoracotomy was the mainstay procedure for obtaining tissue diagnosis and resection. However, video-assisted thoracoscopy (VATS) is an amendable and less-invasive means of tumor removal. We report a case of a posterior mediastinal extramedullary hematopoietic mass in a forty-two year old male in which VATS was utilized for diagnosis and resection.

Large solitary fibrous tumor of the kidney: report of two cases and review of the literature

Solitary fibrous tumors are spindle cell neoplasms frequently arising in the serosal surface as well as a variety of other sites. We report two cases of large solitary fibrous tumor arising in the kidney, clinically thought to be renal cell carcinoma, in 41- and 72-year-old men. Although large in size (13.0 and 14.0 cm in greatest dimension, respectively), both lesions were well circumscribed and composed of a mixture of spindle cells and dense collagenous bands with no areas of necrosis or cystic changes noted macroscopically or microscopically. Immunohistochemical studies revealed reactivity for vimentin, CD34, collagen IV, and bcl-2 protein in both cases, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of solitary fibrous tumor of the kidney. Solitary fibrous tumor of the kidney is rare but may present as a large mass that may be clinically confused with carcinoma or sarcoma.

Neutron yields from 155 MeV/nucleon carbon and helium stopping in aluminum

Neutron fluences have been measured from 155 MeV/nucleon 4He and 12C ions stopping in an Al target at laboratory angles between 10 and 160 deg. The resultant spectra were integrated over angle and energy above 10 MeV to produce total neutron yields. Comparison of the two systems shows that approximately two times as many neutrons are produced from 155 MeV/nucleon 4He stopping in Al and 155 MeV/nucleon 12C stopping in Al. Using an energy-dependent geometric cross-section formula to calculate the expected number of primary nuclear interactions shows that the 12C + Al system has, within uncertainties, the same number of neutrons per interaction (0.99 +/- 0.03) as does the 4He + Al system (1.02 +/- 0.04), despite the fact that 12C has three times as many neutrons as does 4He. Energy and angular distributions for both systems are also reported. No major differences can be seen between the two systems in those distributions, except for the overall magnitude. Where possible, the 4He + Al spectra are compared with previously measured spectra from 160 and 177.5 MeV/nucleon 4He interactions in a variety of stopping targets. The reported spectra are consistent with previously measured spectra. The data were acquired to provide data applicable to problems dealing with the determination of the radiation risk to humans engaged in long-term missions in space; however, the data are also of interest for issues related to the determination of the radiation environment in high-altitude flight, with shielding at high-energy heavy-ion accelerators and with doses delivered outside tumor sites treated with high-energy hadronic beams.

Chronic childhood illness and maternal mental health--why should we care?

This study evaluated which factors most influenced the impact of childhood asthma on the child's family. Seventy children/families seen at a tertiary-care hospital for asthma were evaluated. Stepwise multiple regression examined the effects of illness severity; family socioeconomic status (SES); family structure; social support; child's emotional characteristics; parent's health; family functioning; and maternal psychological distress on the Family Impact of Illness Scale. Analysis indicated that only the parent's Psychiatric Symptom Index significantly predicted impact scores. The most important predictors of how much impact a child's asthma has on the family are parental emotional distress and amount of social support.

Neutron yields from 435 MeV/nucleon Nb stopping in Nb and 272 MeV/nucleon Nb stopping in Nb and Al

Neutron fluences were measured from 435 MeV/nucleon Nb ions stopping in a Nb target and 272 MeV/nucleon Nb ions stopping in targets of Nb and Al for neutrons above 20 MeV and at laboratory angles between 3 degrees and 80 degrees. The resultant spectra were integrated over angles to produce neutron energy distributions and over energy to produce neutron angular distributions. The total neutron yields for each system were obtained by integrating over the angular distributions. The angular distributions from all three systems are peaked forward, and the energy distributions from all three systems show an appreciable yield of neutrons with velocities greater than the beam velocity. Comparison of the total neutron yields from the two Nb + Nb systems suggests that the average neutron multiplicity decreases with decreasing projectile energy. Comparison of the total yields from the two 272 MeV/nucleon systems suggests that the total yields show the same dependence on projectile and target mass number as do total inclusive neutron cross sections. The data are compared with Boltzmann-Uehling-Uhlenbeck model calculations.

Production of neutrons from interactions of GCR-like particles

In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations.

Local anesthesia for fine-needle aspiration biopsy of palpable breast masses: the effectiveness of a jet injection system

To determine the effectiveness of the Biojector 2000 needle-free lidocaine injection system in achieving satisfactory local anesthesia for fine-needle aspiration (FNA) of palpable breast lesions, we studied 29 female patients. Each patient served as her own control and had two FNA biopsies performed on the lesion. The first FNA biopsy was preceded by either no anesthesia, ethyl chloride cold spray, or traditional needle lidocaine injection. The second FNA was preceded by the Biojector 2000. Twenty-four patients (83%) reported that they preferred the Biojector 2000 over either no anesthesia, ethyl chloride spray, or needle and syringe lidocaine injection. The Biojector 2000 needle-free injection system is an effective and useful method of local anesthesia for FNA of palpable breast masses.

Detection of hyperdiploid malignant cells in body cavity effusions by fluoresence in situ hybridization on ThinPrep slides

BACKGROUND

Benign body cavity effusions sometimes cannot be distinguished from malignant ones by conventional cytology. The authors performed fluorescence in situ hybridization (FISH) on ThinPrep slides using chromosome specific probes to see if hyperdiploid malignant cells could be detected in 20 body cavity effusions. The results were then compared with those of conventional cytology.

METHODS

A total of 20 body cavity effusions from 19 patients were studied using conventional cytology and FISH. Probes specific for chromosomes 3, 8, 10, and 12 were used to detect hyperdiploidy on ThinPrep slides (Cytyc Corporation, Boxborough, MA).

RESULTS

A total of 13 patients had malignant conditions (either prior history of malignancy or the presence of malignancy anywhere in the body). Conventional cytology and FISH were both positive in 5 of these patients (6 samples) and negative in 2 patients. The results for one sample were inconclusive by both methods. There were 5 discrepant cytology-FISH results in patients with malignant conditions. One sample was positive by FISH and negative by cytology, one was positive by FISH and "atypical" by cytology, and three were inconclusive by FISH and negative by cytology. FISH results were either negative (in 4 samples) or inconclusive (in 2 samples) in the 6 patients with benign conditions.

CONCLUSIONS

FISH can detect hyperdiploid malignant cells in body cavity effusions and is especially useful when the major cell population consists of malignant cells that cannot be differentiated from mesothelial or "atypical" cells. It is less useful in detecting a small population of malignant cells hidden in an inflammatory or reactive cell background. More studies are needed to establish diagnostic criteria further and to assess the clinical usefulness of this procedure.

Stereotactic radiosurgery of arteriovenous malformations: pathologic changes in resected tissue

Both stereotactic radiosurgery and microsurgery are treatment modalities for arteriovenous malformations (AVM), and more recently, multimodality treatment using these approaches has been utilized. We surgically resected AVMs from 33 patients (ages 7-64 years old, mean age 30.4) 1-11 years after radiosurgery. AVM volumes were 0.8-117 cm3 (mean 21.6 cm3), and doses ranged from 4.6-45 GyE (mean 21.2 GyE). AVMs resected were submitted for pathologic review. Each AVM was evaluated for the following radiation changes, and the number of AVMs demonstrating these changes were noted: endothelial proliferation (27), hyaline (18) and calcium (10) in AVM vessel walls, partial (9) or complete (24) thrombosis of some AVM vessels, and necrosis of vessels (15) and adjacent brain tissue (11). A semiquantitative scale (mild, moderate, severe) incorporating the aforementioned changes present in each case classified the extent of radiation-induced change. There was a significant correlation (r = 0.624, p < 0.01) between extent of radiation change and dose of radiation received. There was no absolute radiation dose threshold below which radiation-induced changes were absent. However, all but one patient receiving greater than 20 GyE developed moderate to severe radiation vascular changes and the 3 patients treated with greater than 30 GyE all had severe radiation-induced changes. Radiation changes in AVMs following stereotactic radiosurgery appear to be dose-related. The correlation of dose to extent of radiation change may allow the determination of the optimal dose of radiation to treat AVMs.

Core needle biopsy. A useful adjunct to fine-needle aspiration in select patients with palpable breast lesions

BACKGROUND

Fine-needle aspiration (FNA) biopsy is an established, highly accurate method for diagnosing palpable breast lesions. However, in some cases a definitive diagnosis cannot be made by FNA alone, either due to the inherent limitations of cytology itself or the ability to obtain adequate material for diagnosis. This study evaluated the usefulness of a supplemental core needle biopsy performed by a cytopathologist in conjunction with an FNA biopsy in select patients.

METHODS

Twelve patients with palpable breast lesions underwent the combined FNA/core needle biopsy procedure during the study period from March 1995 through March 1996. All 12 patients first had an FNA aspiration that was preliminarily evaluated by the FNA cytopathologist while the patient was at the clinic. If the cytopathologist was unable to render a definitive diagnosis of the lesion type or if a repeat FNA was requested by the clinician because of a previous non-definitive FNA result, a core needle biopsy was then performed.

RESULTS

When the FNA and the core needle biopsies were reviewed together, a correct definitive diagnosis was made in 10 of the 12 cases. In contrast, review of the FNA material alone yielded a correct definitive diagnosis in only five cases.

CONCLUSIONS

The supplemental core needle biopsy was found to be especially useful in: 1) providing a definitive diagnosis of infiltrating carcinoma in those cases in which the FNA diagnosis was reported as "suspicious;" 2) providing ample tissue for ancillary studies; and 3) differentiating a phyllodes tumor from a fibroadenoma. It is the authors' opinion that the FNA cytopathologist is the physician best qualified to perform the combined FNA/core needle biopsy procedure should he/she deem it necessary.

Surgical resection of large incompletely treated intracranial arteriovenous malformations following stereotactic radiosurgery

Although radiosurgery is effective in obliterating small arteriovenous malformations (AVMs), it has a lower success rate for thrombosing larger AVMs. The authors surgically resected AVMs from 33 patients ranging in age from 7 to 64 years (mean 30.4 years) 1 to 11 years after radiosurgery. Initial AVM volumes were 0.8 to 117 cm3 (mean 21.6 cm3), and doses ranged from 4.6 to 45 GyE (mean 21.2 GyE). Of 27 AVMs in eloquent or critical areas, 10 were located in language, motor, sensory, or visual cortex, 11 in the basal ganglia/thalamus, one each in the brainstem, hypothalamus, and cerebellum, and three in the corpus callosum. Venous drainage was deep in 13, superficial in 12, or both in eight lesions. Spetzler-Martin grades were II in one, III in 12, IV in 16, and V in four patients. Eight patients experienced rebleeding after radiosurgery but prior to surgery. Three patients developed radiation necrosis and 25 underwent endovascular embolization prior to surgery. At surgery the AVMs were found to be markedly less vascular, partially thrombosed, and more easily resected, compared to those seen in patients who had not undergone radiosurgery. Pathological investigation showed endothelial proliferation with hyaline and calcium in vessel walls. There was partial or complete thrombosis of some AVM vessels and evidence of vessel and brain necrosis in many cases. Complete resection was achieved in 28 patients and partial resection in five. Clinical outcome was excellent or good in 31 cases, and two patients died of rebleeding from residual AVM. Four patients' conditions worsened following microsurgical resection. Final clinical outcome was largely related to the pretreatment grade. Radiosurgery several years prior to open microsurgery may prove to be a useful adjunct in treating unusually large and complex AVMs.

The fragmentation of 510 MeV/nucleon iron-56 in polyethylene. I. Fragment fluence spectra

The fragmentation of 510 MeV/nucleon iron ions in several thicknesses of polyethylene has been measured. Non-interacting primary beam particles and fragments have been identified and their LETs calculated by measuring ionization energy loss in a stack of silicon detectors. Fluences, normalized to the incident beam intensity and corrected for detector effects, are presented for each fragment charge and target. Histograms of fluence as a function of LET are also presented. Some implications of these data for measurements of the biological effects of heavy ions are discussed.

The incidence of high grade prostatic intraepithelial neoplasia in needle biopsies

PURPOSE

High grade prostatic intraepithelial neoplasia is the most likely precursor of invasive prostate cancer. The identification of prostatic intraepithelial neoplasia in needle biopsy specimens warrants repeat biopsy because of its high predictive value for cancer. The incidence of prostatic intraepithelial neoplasia in contemporary needle biopsies is unknown.

MATERIALS AND METHODS

To determine the incidence of patients requiring repeat needle biopsy because of abnormal findings in needle aspirations (high grade prostatic intraepithelial neoplasia and microscopic foci suspicious for but not diagnostic of malignancy), we compared the pathological findings in 400 prostatic needle biopsies, including 200 consecutive cases from an academic medical center (Mayo Clinic) and an equal number from a private practice laboratory (Glendale Memorial Hospital and Health Center).

RESULTS

The biopsies revealed similar findings from the 2 medical centers: benign prostatic tissue in 41.5 to 50% of the cases, prostatic intraepithelial neoplasia in 16.5 to 9.5%, foci suspicious for but not diagnostic of malignancy in 1.5 to 2.5% and cancer in 40.5 to 38% (Mayo Clinic versus Glendale Memorial, respectively). Clinical information was available from the 200 Mayo Clinic patients who underwent biopsy, and there was no difference in the distribution of findings by digital rectal examination or transrectal ultrasound, although the median serum prostate specific antigen concentration was higher in patients with prostatic intraepithelial neoplasia and cancer than in those with benign biopsies.

CONCLUSIONS

High grade prostatic intraepithelial neoplasia is a frequent finding in needle biopsies and is present in up to 16.5% of the cases. There was no apparent difference in the incidence of prostatic intraepithelial neoplasia and cancer between 2 geographically diverse medical centers. Up to 18% of patients are candidates for another biopsy based on needle biopsy findings of prostatic intraepithelial neoplasia or foci suspicious for but not diagnostic of malignancy.

The fragmentation of 670A MeV neon-20 as a function of depth in water. III. Analytical multigeneration transport theory

This is the final report of a detailed study of the interaction of 670A MeV neon ions with water, used as a presumed tissue-equivalent target. A first comparison of the data with theoretical fluence spectra predicted by the one-generation heavy-ion transport code HZESEC was reported previously. In the present article, subsequent nuclear interactions of the fragment are taken into account, using the LBLBEAM multigeneration heavy-ion transport code, which incorporated new features and modifications intended to address some of the approximations made in the previous calculation. The LBLBEAM code uses the method of characteristics and an iterative procedure to solve a one-dimensional Boltzmann transport equation for the first through third successive generations of nuclear reaction products; it includes a recent version of the semiempirical model used to derive nuclear interaction cross sections. The stopping power used for the theory was calculated in the same way that experimental time-of-flight and energy-loss data are converted to obtain a comparison independent of stopping power; accordingly, good agreement was found between calculated and measured neon fluence spectra in the Bragg peak region. Multiple scattering effects were considered separately for each isotope in the present work. Acceptance factors were calculated as previously, assuming that all projectile fragments originate from the first nuclear interaction. The results show that lower-mass isotopes can account for the high-LET portions of the spectrum in measured fluence spectra. Third-generation products become increasingly important as a source of lighter fragments for depths comparable with the primary particle mean free path, accounting for between one-third and one-half of carbon and lighter particles near the Bragg peak; higher-order interactions were negligible for the detector geometry and material thicknesses examined. Agreement between measured and calculated fluence spectra is 30% (20% for integral fluences). Inclusion of hydrogen, helium, and lithium fragments improves agreement between calculated and measured RBE values for spermatogonial cell survival, but tertiary particle acceptance and track structure effects need to be understood in greater detail to predict RBE accurately.

Measurements of n-p correlations in the reaction of relativistic neon with uranium

We report a preliminary measurement of coincident neutron-proton pairs emitted at 45 degrees in the interaction of 400, 530, and 650 MeV/A neon beams incident on uranium. Charged particles were identified by time of flight and momentum, as determined in a magnetic spectrometer. Neutral particles were detected using a thick plastic scintillator, and their time of flight was measured between an entrance scintillator, triggered by a charged particle, and the neutron detector. The scatter plots and contour plots of neutron momentum vs. proton momentum appear to show a slight correlation ridge above an uncorrelated background. The projections of this plane on the n-p momentum difference axis are essentially flat, showing a one standard deviation enhancement for each of the three beams energies. At each beam energy, the calculated momentum correlation function for the neutron-proton pairs is enhanced near zero neutron-proton momentum difference by approximately one standard deviation over the expected value for no correlation. This enhancement is expected to occur as a consequence of the attractive final state interaction between the neutron and proton (i.e., virtual or "singlet" deuterons). The implications of these measurements are discussed.