Stereotactic core needle biopsy in non-palpable breast lesions. What number is needed?

PURPOSE: To investigate whether three stereotactic core needle biopsies (S-CNB) in non-palpable breast lesion are enough for accurate preoperative diagnosis. MATERIAL AND METHODS: Between September 1994 and December 2000, 523 patients with mammographically detected breast lesions and who proceeded to surgery were preoperatively stereotactically biopsied with an automated 14-gauge biopsy device. Three samples were taken from each lesion irrespective of whether the lesion presented as "microcalcifications only", "microcalcifications and a mass", or a "mass, architectural distorsion, or stellate lesion without microcalcifications". The histopathology was divided into three subgroups: diagnostic, atypia (ranging from atypical cells to probably cancer), and non-diagnostic material. RESULTS: Post-surgical histopathology diagnosed 454 (87%) malignant tumors and 69 (13%) benign lesions. Three S-CNB correctly diagnosed the malignant tumors in 84% in the subgroup "microcalcifications only". In the category "microcalcifications and a mass", the diagnostic accuracy was 97% and in the subgroup "mass, architectural distorsion, or stellate lesion without microcalcifications" 3 S-CNB resulted in 93% correct diagnostic material. In 19 of the 454 patients (4%) 1, 2 or all 3 preoperative S-CNB showed atypia. In 20 patients (4%), all 3 S-CNB were non-diagnostic. Thirteen of these 20 patients had "microcalcifications only" and 7 had a mass without microcalcifications. CONCLUSION: Three S-CNB were enough for correct diagnosis in "masses, architectural distorsions, or stellate lesions without microcalcifications" and in "microcalcifications and a mass", but were not sufficient in "microcalcifications only".

Comparison of preoperative simultaneous stereotactic fine needle aspiration biopsy and stereotactic core needle biopsy in ductal carcinoma in situ of the breast.

PURPOSE: To compare the preoperative results of stereotactic fine needle aspiration biopsy (S-FNAB) with stereotactic core needle biopsy (S-CNB) performed simultaneously in breast lesions with the postoperative histopathological diagnosis of ductal carcinoma in situ (DCIS) of all histological grades. MATERIAL AND METHODS: 733 consecutive stereotactic biopsies were performed between May 1993 and June 1999. In 72 patients with mammographic findings suspicious of malignancy who were subjected to breast surgery, postoperative histopathology showed DCIS. Preoperatively, S-FNAB and S-CNB had been done simultaneously in all patients, S-FNAB with spinal needle 0.7 or 0.9 mm and S-CNB was performed with an automated 2.1-mm biopsy gun. An average of 3 S-FNABs and 3 S-CNBs were performed in each patient. RESULTS: In 56 (78%) of the 72 patients S-CNB showed DCIS. In 3 patients (4%) the S-CNB revealed "probable carcinoma", in 7 patients (10%) "atypia" and in 6, the lesions were benign. In 34 (47%) of the 72 women S-FNABs showed carcinoma, not otherwise specified. In 6 cases (8%) the S-FNABs showed "probable carcinoma" and in 12 patients (17%) "atypia"; 8 lesions were benign and 12 not diagnostic. CONCLUSION: S-CNB was superior to S-FNAB in diagnosing DCIS. Only 6 patients (8%) received a benign or non-diagnostic preoperative diagnosis with S-CNB compared to 20 patients (28%) with S-FNAB. S-CNB was superior to S-FNAB for preoperative diagnosis of DCIS, but S-FNAB could further increase the sensitivity of the biopsy since it diagnosed cancer in 4 cases where S-CNB showed benign material.

Pre-operative simultaneous stereotactic core biopsy and fine-needle aspiration biopsy in the diagnosis of invasive lobular breast carcinoma.

PURPOSE: To determine the diagnostic value of stereotactic core needle biopsy (SCNB) in comparison to stereotactic fine-needle aspiration biopsy (SFNAB) in patients with invasive lobular carcinoma (ILC). MATERIAL AND METHODS: Twenty-two patients with clinical or mammographic findings suspicious of malignancy underwent surgery where postoperative histopathology showed ILC. Pre-operative attempts of diagnosis were made using SFNAB and SCNB. SFNAB was done with a spinal needle 0.7- or 0.9-mm and SCNB was simultaneously performed with an automated 2.1-mm biopsy gun in all patients. RESULTS: SFNAB was diagnostic of carcinoma in 9 women, showed "probable carcinoma" in 5 and "atypia" in 3. In the remaining 5 women, SFNAB showed no atypia. SCNB diagnosed ILC in 20 patients and showed ILC as well as invasive ductal carcinoma (IDC) in 1. Ductal carcinoma in situ was suggested in the remaining patient. CONCLUSION: SCNB was superior to SFNAB in diagnosing ILC and did not miss any carcinoma, whereas SFNAB was non-diagnostic in 8 cases. SCNB is thus recommended in patients with suspicion of ILC of the breast.

Radiological review of incidence breast cancers.

OBJECTIVES: To examine the rate of incidence cancers detectable on review of previous screening mammograms using two reviewing methods. To compare the results with a previous study of interval cancers using the same reviewing methods. SETTING: Almost 50000 women are regularly invited for service screening at Stockholm Söder Hospital. From 1989 to 1993, 119 women were identified with breast cancer detected at screening and the previous round attendance (incidence cancer). METHODS: Screening mammograms, obtained before detection of the incidence cancers, were reviewed first mixed with other screening images (ratio 1:8) and then non-mixed. Reviewers from the screening unit responsible for the mammograms as well as reviewers from other units interpreted all images by both single and double reading. RESULTS: The proportion detected on retrospective review varied between 5% and 50% depending on the review method used and the number of reviewers included to classify a case as truly identified. Generally more cancers were detected when non-mixed samples of mammograms were reviewed than when mixed samples were reviewed (mean increase 23%) and when interpreted by double reading compared with single reading (mean increase 14%). CONCLUSIONS: In an experimental retrospective set up, fewer incidence cancers were identified in mixed than in non-mixed review. Generally more incidence cancers were identified on review (22%) than previously reported for interval cancers (14%), probably reflecting differences in tumour biology and growth. How many women with potentially visible incidence cancers would have benefited from earlier tumour detection still needs to be evaluated.

Two models for radiological reviewing of interval cancers.

OBJECTIVES: To compare two different review methods of examining how many of our interval cancers could be regarded as missed cases (overlooked and misinterpreted owing to observer's error). SETTING: A mass screening programme in Stockholm 1989-91, performed at five independent screening units. 107,846 women attended for screening (70.6% of those invited), and 207 women with interval breast cancers were identified. Interval cancers from two of the units, 104 cases, are reviewed in this study. METHODS: Screening examinations preceding the interval cancer diagnoses were reviewed both mixed with other screening images in a ratio 1:8 and non-mixed. Both internal reviewers (from the two units responsible for the screening mammograms) and external reviewers (from the other units) took part in the study. RESULTS: The proportion regarded as missed cases varied between 7% and 34%, depending on what review method was used, and on the number of reviewers included to identify a case as missed. Mixed reviewing reduced the number identified as missed cases by 50% compared with non-mixed reviewing. Whether the reviewer was internal or external made no difference to the results. CONCLUSIONS: Comparing the rate of missed cases from different studies may be misleading unless the same review method is used. No difference in detection rate could be shown whether the radiologist reviewed images from his/her own screening unit or not. Most of our interval cancers were not regarded as missed cases by either of the two methods.

Occurrence of Gasterophilus intestinalis and some parasitic nematodes of horses in Sweden.

A survey was performed on the occurrence of some internal parasites in 461 horses (1-30 years old) slaughtered from October 1992 to September 1993 at the Linköping abattoir in central Sweden. Macroscopical examination was carried out specifically for parasites of the tear ducts and conjunctival sacs of the eyes, and of selected parts of the alimentary tract and cardio-vascular system. The following parasites were found in selected parts of the large intestine: encapsulated cyathostome larvae (in 35.6% of the horses), and mature strongyle worms (17.4%); in the stomach: Gasterophilus intestinalis (12.3% during October-June) and Habronema muscae (1.1%); and in the conjunctival sac: Thelazia lacrymalis (3.1%). Significantly more encapsulated cyathostome larvae were found during January to June than during other times of the year, and horses aged 1-5 years harboured significantly more larvae than older horses. Severe damage to the cranial mesenteric artery and its main branches was noticed in 16 (6.1%) out of 263 horses specifically examined. However, the 4th stage larva of Strongylus vulgaris was only recovered in 6 (2.3%) of the horses. Quantitative and qualitative faecal egg counts were done on 412 and 384 of the horses, respectively. Eggs of strongyles, Parascaris equorum and Strongyloides westeri were found in 78.1%, 1.9% and 0.2% of the faecal samples, respectively. Highest prevalence of strongyle eggs was found during July to September. Third stage larvae of the following nematodes were recovered from faecal cultures: subfamily Cyathostomum sensu lato (78.1%) Triodontophorus spp. (6.5%), Strongylus vulgaris (3.6%), Trichostrongylus axei (1.3%), while Gyalocephalus sp., Oesophagodontus sp., Poteriostomum sp. and Strongylus edentatus each comprised less than 0.5%.

V/Q distribution and correlation to atelectasis in anesthetized paralyzed humans.

Regional ventilation and perfusion were studied in 10 anesthetized paralyzed supine patients by single-photon emission computerized tomography. Atelectasis was estimated from two transaxial computerized tomography scans. The ventilation-perfusion (V/Q) distribution was also evaluated by multiple inert gas elimination. While the patients were awake, inert gas V/Q ration was normal, and shunt did not exceed 1% in any patient. Computerized tomography showed no atelectasis. During anesthesia, shunt ranged from 0.4 to 12.2. Nine patients displayed atelectasis (0.6-7.2% of the intrathoracic area), and shunt correlated with the atelectasis (r = 0.91, P < 0.001). Shunt was located in dependent lung regions corresponding to the atelectatic area. There was considerable V/Q mismatch, with ventilation mainly of ventral lung regions and perfusion of dorsal regions. Little perfusion was seen in the most ventral parts (zone 1) of caudal (diaphragmatic) lung regions. In summary, shunt during anesthesia is due to atelectasis in dependent lung regions. The V/Q distributions differ from those shown earlier in awake subjects.

CT-assessment of dependent lung densities in man during general anaesthesia.

PURPOSE: We aimed to describe the frequency of atelectasis occurring during anaesthesia, to describe the size and pattern of the atelectasis, and to standardise the method of identifying the atelectasis and calculate its area. MATERIAL AND METHODS: Patients (n = 109) scheduled for elective abdominal surgery were examined with CT of the thorax during anaesthesia. RESULTS: In 95 patients (87%) dependent pulmonary densities were seen, interpreted as atelectasis. Two different types of atelectasis were found-homogeneous (78%) and non-homogeneous (9%). Attenuation values in histograms of the lung and atelectasis were studied using 2 methods of calculating the atelectatic area. CONCLUSION: On the basis of the present findings, we defined atelectasis as pulmonary dependent densities with attenuation values of -100 to +100 HU.

Anoplocephala perfoliata in horses in Sweden: prevalence, infection levels and intestinal lesions.

Distal ileum, caecum and proximal colon of 470 horses were examined for helminths during 1 year at an abattoir in central Sweden. The infection levels of the horse tapeworm Anoplocephala perfoliata, their stage of development, site of attachment and gross pathological lesions caused by the worm were recorded. Faecal samples from 395 of the horses were examined specifically for tapeworm segments and eggs in order to correlate these findings with the numbers in the alimentary canal. In total 65% of the horses were infected with A. perfoliata and the mean intensity of infection was 79 worms per infected horse with a maximum of 912. The level of infection was significantly higher in (1) 3rd and 4th than in 1st and 2nd quarter of the year; (2) older horses than in yearlings; (3) females than in males and geldings; (4) thoroughbred and cold-blooded horses than in Swedish standard breeds and ponies. The level of infection was unaffected by the usage of anthelminthics against nematodes. Of the horses examined 51% had 1-100 worms whereas 14% were infected with more than 100 worms. Of the tapeworm positive horses 72% had mixed infections with both adult and juvenile worms, 20% solely juveniles, and 8% solely adults. The severity of intestinal lesions exacerbated by increasing numbers of A. perfoliata. About 11% of the intestines examined had severe lesions, but there was no history of acute abdominal distress in any of the horses included in this study. Although the number of detectable eggs was significantly higher for horses heavily infected with A. perfoliata, the egg recovery among infected horses was only 35%. An additional field survey comprising 218 horses on 88 premises in central and southern parts of Sweden showed that the prevalence of A. perfoliata egg positive horses was the same as found on faecal examination during the abattoir survey.

Phrenic nerve stimulation during halothane anesthesia. Effects of atelectasis.

BACKGROUND: Atelectasis formation during anesthesia may be due to loss of respiratory muscle tone, in particular that of the diaphragm. This was tested by tensing the diaphragm by phrenic nerve stimulation (PNS) and observing the effect on atelectasis. METHODS: Twelve patients (mean age 48 yr) without preexisting lung disease were studied during halothane anesthesia. PNS was executed with an external electrode on the right side of the neck. Chest dimensions and area of atelectasis were studied by computed tomography of the chest. RESULTS: Right-sided PNS against an occluded airway at functional residual capacity reduced the atelectatic area in the right lung from 5.1 to 3.8 cm2. The atelectasis was reduced to 1.1 cm2 after application of positive end-expiratory pressure (PEEP) of 10 cmH2O and large tidal volumes but increased to 2.5 cm2 within 1 min after discontinuation of PEEP. Commencement of PNS immediately after PEEP prevented the atelectasis from increasing, the mean area being 0.9 cm2. In seven patients, in whom the trachea was intubated with a double-lumen endobronchial catheter the atelectatic area was smaller during PNS with an open airway than during positive pressure inflation of the lung with the same volume as inspired during PNS (3.5 and 5.2 cm2, respectively. CONCLUSIONS: The findings indicate that contracting the diaphragm in the anesthetized subject reduces the size of atelectasis.

Analysis of lung density by computed tomography before and during general anaesthesia.

Pulmonary structure was analysed by means of computed tomography (CT) in 20 lung-healthy patients, relating tissue density to the attenuation value (AV) of a picture element. Regional density of pulmonary tissue (rlung) was determined using mean lung density in five regions of interest (ROI1-5) (sector method). Vertical and horizontal distributions of x-ray attenuation were analysed by density profiles, relating AV values to evenly distributed and normalised length scales. In group I (n = 12), CT-densitometry was obtained in awake, supine patients and after induction of general anaesthesia. In group II (n = 8), the effect of mechanical ventilation with positive end-expiratory pressure (PEEP, 1.0 kPa [10 cmH2O]) was studied. In the awake state, a vertical tissue density difference between the top and bottom of the lung was found in all patients, accounting for a mean of 0.235 g.cm-3 (right lung) and 0.199 g.cm-3 (left lung). Only minor changes were seen in the horizontal lung density profiles. After induction of anaesthesia, x-ray attenuation of ROI1-4 showed no significant differences when compared with the awake state. The basal lung areas (ROI5) revealed a significantly increased tissue density (P < or = 0.01), reaching mean values of 0.94 g.cm-3 (right lung) and 0.814 g.cm-3 (left lung). Similarly, vertical density profiles showed a markedly enhanced rlung of the bottom of the lung in all patients, interpreted as atelectasis. The amount of atelectasis accounted for 4.8 +/- 2.6% (right lung) and 4.7 +/- 2.1% (left lung) of the intrapulmonary area.(ABSTRACT TRUNCATED AT 250 WORDS)

Atelectasis and lung function in the postoperative period.

Thirteen patients with healthy hearts and lungs, and with a mean age of 68 years, who were scheduled for lower abdominal surgery during isoflurane anaesthesia with muscular paralysis, were investigated with arterial blood gases, spirometry, pulmonary x-ray and computed tomography (CT) of the chest before and during anaesthesia, as well as during the first 4 postoperative days. Before anaesthesia, lung function and gas exchange were normal in all patients. Pulmonary x-ray and CT scans of the lungs were also normal. During anaesthesia, 6 of 13 patients developed atelectasis (mean 1.0% of intrathoracic transverse area in all patients). Two hours postoperatively, 11 of 13 patients had atelectasis and the mean atelectatic area was 1.8%. Pao2 was significantly reduced by 2.1 kPa to 9.8 kPa. On the first postoperative day, the mean atelectasis was unaltered (1.8%). None of the atelectasis found on CT scanning could be detected on standard pulmonary x-ray. Forced vital capacity (FVC) and forced expired volume in 1 s (FEV1) were significantly decreased to 2/3 of preoperative level. Pao2 was significantly reduced to less than 80% of the preoperative level (mean 9.4 kPa). There were significant correlations between the atelectatic area and the impairment in FVC, FEV1, and Pao2. Spirometry and blood gases improved during the succeeding postoperative days, and atelectasis decreased. No patient suffered from pulmonary complications, as judged from clinical criteria and pulmonary x-ray, in contrast to the findings of atelectasis in 85% of the patients by computed tomography.

Chronic obstructive pulmonary disease and anaesthesia: formation of atelectasis and gas exchange impairment.

Gas exchange impairment and the development of atelectasis during enflurane anaesthesia were studied in 10 patients (mean age 70 yrs) with chronic obstructive pulmonary disease (COPD). Awake, no patient displayed atelectasis as assessed by computed X-ray tomography. The ventilation/perfusion distribution (VA/Q), studied by the multiple inert gas elimination technique, displayed an increased dispersion of VA/Q ratios (the logarithmic standard deviation of the perfusion distribution, mean log Q SD 0.99; upper 95% confidence limit of normal subject: 0.60), and increased perfusion of regions with low VA/Q ratios (0.005 less than VA/Q less than 0.1: 5.4% of cardiac output). Shunt was negligible (mean 0.6%). Computed chest tomography showed significantly larger cross-sectional thoracic areas than previously seen in subjects with healthy lungs (p less than 0.01). No atelectasis was seen in any patient. During anaesthesia there was a further worsening of the VA/Q mismatch with significantly increased log Q SD (1.29, p less than 0.05) but no increase in shunt (mean 1%). Minor atelectatic areas were noted in three patients, the others displayed no atelectasis at all. Chest dimensions were reduced by no more than 3% during anaesthesia, suggesting an unchanged or only minimally affected functional residual capacity. These findings contrast with those seen in patients with healthy lungs in whom atelectasis and shunt regularly develop during anaesthesia.

Atelectasis causes gas exchange impairment in the anaesthetised horse.

The anatomical basis of gas exchange impairment in the anaesthetised horse was studied by computerised tomography (CT; three shetland ponies) and morphological analysis (one pony and three horses). By means of CT, densities were seen in dependent lung regions early during anaesthesia, both with spontaneous breathing and with mechanical ventilation. The densities remained for some time where they had initially been created when the animal was turned from dorsal to sternal recumbency. Deep insufflation of the lungs reduced the dense area. Gas exchange was impaired roughly in proportion to the dense area. On histological analysis, the densities were atelectatic and congested with blood. Gravimetry showed no more extravascular water per unit lung tissue in the atelectatic than in the 'normal' regions, and the blood content was increased only slightly. It is concluded that the horse develops atelectasis in dependent lung regions early during anaesthesia in dorsal recumbency, and that atelectasis is the most likely explanation for the large shunt and impaired arterial oxygenation regularly seen during anaesthesia.

The influence of body position and differential ventilation on lung dimensions and atelectasis formation in anaesthetized man.

The effects of body position and anaesthesia with mechanical ventilation on thoracic dimensions and atelectasis formation were studied by means of computerized tomography in 14 patients. Induction of anaesthesia in the supine position reduced the cross-sectional area for both lungs and caused atelectasis formation in dependent lung regions in 4/5 patients. Conventional ventilation with positive end-expiratory pressure (PEEP) increased thoracic dimensions and reduced, but did not eliminate, the atelectatic areas. The vertical diameters of both lungs were smaller in the lateral position as compared to the supine position (16.7 vs 10.4 cm in the left lung and 17.3 vs 12.8 cm in the right lung). The lateral positioning also caused a large reduction of the atelectatic area in the non-dependent lung. Differential ventilation with selective PEEP to the dependent lung eliminated (3/8 patients) or reduced (5/8 patients) dependent lung atelectasis. It can be concluded that lung geometry is altered in the lateral position: the shape of the lung makes the vertical diameter of each lung less in the lateral position, compared to the supine position. The atelectatic areas are mainly located in the dependent lung in the lateral position, and these atelectatic areas could be further reduced by selective PEEP to this lung.

Atelectasis and gas exchange impairment during enflurane/nitrous oxide anaesthesia.

The development of atelectasis and effects on gas exchange during enflurane anaesthesia in nitrogen/oxygen or nitrous oxide/oxygen (inspired oxygen fraction 0.4) were studied in 16 lung-healthy patients (mean age 49 years). Awake, no subject displayed atelectasis as assessed by computed x-ray tomography of the thorax. Pulmonary gas exchange, studied by multiple inert gas elimination technique, and blood gases were normal. After 10 min of enflurane anaesthesia in nitrogen/oxygen, 14 of 16 subjects had developed atelectasis. After 30 min of enflurane anaesthesia in nitrogen/oxygen or nitrous oxide/oxygen, all patients had developed atelectasis, and a further increase was observed after 90 min of anaesthesia to approximately 5% of the intrathoracic area. There was no difference between the two anaesthesia groups. In the nitrogen group, shunt rose to a maximum of 5.8% at 30 min of enflurane anaesthesia, with a significant reduction to the initial anaesthesia level after 90 min of anaesthesia (3.4%). Perfusion of poorly ventilated lung regions (low VA/Q) averaged 4-5% and did not vary significantly during the anaesthesia. In the nitrous oxide group, shunt increased to 6.3% after 90 min of anaesthesia, and there was a parallel decrease in perfusion of low VA/Q regions. The findings suggest that besides prompt collapse of lung tissue during induction of anaesthesia, absorption of gas from closed-off or poorly ventilated regions takes place and further increases the atelectatic area.

Pulmonary densities during anaesthesia. An experimental study on lung morphology and gas exchange.

The nature of dense areas in dependent lung regions regularly seen in anaesthetized humans was examined in a sheep model. During anaesthesia with muscle paralysis and mechanical ventilation dense areas in dependent lung regions could be seen by means of computerized tomography (CT). They had the same location and the same attenuation as in anaesthetized humans. Gas exchange impairment tended to increase in proportion to the size of the dense area on the CT scan. Microscopy showed that the densities in the sheep were atelectatic lung regions, with no or little interstitial oedema and only minor vascular congestion. The atelectatic lung tissue was sharply demarcated and the lung tissue in the immediate vicinity was well aerated, or even hyperinflated. Gravimetry showed the same amount of extravascular fluid and blood per unit lung weight in the atelectatic lung and in the aerated lung region. It is concluded that the densities appearing in dependent lung regions during anaesthesia are caused by atelectasis.

Barbiturate anaesthesia does not cause pulmonary densities in dogs: a study using computerized axial tomography.

The occurrence of roentgenological densities in dependent lung regions was studied in 28 mongrel dogs (mean weight 18.7 kg) during barbiturate anaesthesia and mechanical ventilation. The densities were analysed by means of computerized tomography, permitting transaxial projections of the thorax. Two dogs showed small densities in dependent lung regions, corresponding to 1% of the total intrathoracic area. In five dogs there were small areas of probably increased density, without sharp delineation, in dependent regions. The remaining 21 dogs (75%) exhibited no densities. The frequency of such densities was thus much lower than has been found in anaesthetized human subjects. Moreover, the densities were relatively smaller than those in man and qualitatively different. It is concluded that the development of dependent lung densities differs both quantitatively and qualitatively between dogs and human subjects.

Cardiac function and central haemodynamics in severe chronic obstructive lung disease. Acute and long-term effects of felodipine.

Eleven patients, with advanced chronic obstructive lung disease (COLD), received an infusion of the calcium antagonist felodipine at a rate of 0.9 mg/h. Pulmonary and systemic vascular resistances (PVR and SVR) at rest were reduced by 18% (p less than 0.05) and 33% (p less than 0.001), respectively. Cardiac output increased by 33%. The right ventricular and left ventricular ejection fractions (RVEF and LVEF), measured by equilibrium gated radionuclide ventriculography, increased by 32% (p less than 0.01) and 25% (p less than 0.01), respectively. During exercise both PVR and SVR fell by a mean of 30% (p less than 0.01). RVEF and LVEF both increased by about 14% (p less than 0.05 and p less than 0.01). After three months of oral felodipine treatment, a dose-related decrease in PVR was noted at rest (r = -0.83) compared with pretreatment values. There was an increase in RVEF which correlated to a reduction in PVR (r = -0.76). Three patients discontinued the trial due to side effects. It is concluded that the reduction of PVR induced by felodipine is accompanied by an improvement in right heart function as measured by ejection fraction measurements.