[Targeted therapy in lung cancer: molecular testing using cytological specimens]

Important advances in lung cancer treatment have been made over the last decade. Several drugs designed to target molecular pathways involved in cancer-cell growth and survival have been shown to be effective in a selected fraction (<20%) of non-small cell lung cancer patients. Somatic mutations in several genes (i.e.: EGFR and KRAS) can predict patient's response to targeted therapies. Those mutations are commonly detected on histopathological samples (core-needle biopsy/ surgical resection). However, when tissue biopsies are not available, molecular testing has to be performed on cytological specimens. Issues raised by molecular testing on cytological specimen are discussed in this article.

[Fine needle aspiration of the thyroid: the value of on-site evaluation]

Thyroid nodules are very common in the general population and most of them are benign. Fine needle aspiration (FNA) of the thyroid is routinely used because it is a rapid, simple, accurate and cost-effective technique which allows the adequate selection of patients who should be managed surgically. However, the diagnostic yield of FNA is variable and depends of multiple factors including the one who performs FNA, the aspiration and cytological slide preparation techniques, and cytopathologist's experience. On-site evaluation of thyroid FNA material and close clinico-pathological collaboration offer many advantages and optimizes the yield of FNA.

Bronchoalveolar cytology for diagnosing pulmonary GVHD after bone marrow transplant in children

BACKGROUND

Cytological composition of bronchoalveolar lavage (BAL) fluid in pediatric bone marrow transplant (BMT) recipients with pulmonary complications has not been comprehensively described and BAL specific markers of pulmonary GVHD are lacking. The aim of this retrospective study was to assess the role of BAL in the diagnosis of pulmonary GVHD by comparing BAL cytological findings between pediatric allogenic BMT patients with pulmonary complications and oncology children receiving chemotherapy alone.

METHODS

Retrospective analysis of BAL specimens for cytology, total and differential cell counts and presence of infections.

RESULTS

Seventeen BMT and 13 chemotherapy BAL were analyzed. BAL total cell count was increased but similar between groups (96.9 x 10(4) vs. 98.2 x 10(4), P = NS). BAL cellular composition differed considerably between groups with a significantly higher number of lymphocytes (18% vs. 6.25%, P = 0.03) and a significantly lower number of neutrophils (25.9% vs. 58%, P = 0.02) in BMT BAL specimens. Atypical epithelial cells were significantly more frequent (75% vs. 30.8%, P = 0.027), and significantly more severe (P = 0.01) in BMT patients. The presence and severity of atypia was not associated with infection or pneumotoxic drug exposure (P = NS).

CONCLUSION

BAL cytology differs significantly between BMT and chemotherapy patients. The presence BAL lymphocytosis and severe epithelial cell atypia concomitantly to respiratory symptoms and GVHD in other organs may suggest the diagnosis of pulmonary GHVD. Prospective studies assessing the reliability of this finding combined with markers such as epithelial cell apoptosis and increased cytokines are needed.

Primary intrapulmonary thymoma: A systematic review

AIM

This article reviews the literature on the clinical features, diagnosis and management of primary intrapulmonary thymoma.

METHODS

Medline, Embase and Cochrane Library searches were performed on all relevant Anglo-Saxon language articles. The search words included "primary pulmonary thymoma" and "intrapulmonary thymoma". Secondary references were obtained from key articles. Prognostic and treatment strategies were analyzed by the Kaplan-Meier method, comparisons between curves were made using log rank test.

RESULTS

The searches yielded 25 cases of primary intrapulmonary thymoma. Median follow-up was 9 months (1 day to 13 years). At follow-up, 14 patients were tumor free, one patient had a local recurrence 8 years after radiotherapy, one patient responded favorably to radiotherapy, six patients died and three patients were lost to follow-up. The presence of a paraneoplastic syndrome decreased survival (P=0.02), however, histological subgroup (P=0.216), clinical stage (P=0.63) and tumor size (P=0.288) did not affect survival. Survival in surgically managed patients was significantly better than in conservatively managed patients (P=0.039). Adjuvant radiotherapy did not provide any benefit (P=0.4).

CONCLUSION

Complete resection of primary intrapulmonary thymomas appears sufficient in non-malignant tumors. Because of the risk of late local recurrence, long-term regular clinical follow-up is warranted.

Development of a quantitative TaqMan RT-PCR for respiratory syncytial virus

Respiratory syncytial virus (RSV) is a ubiquitous RNA virus of the family Paramyxoviridae that may interfere with graft tolerance and with other interstitial lung diseases. The low viral titre observed in the immunodeficient transplanted patients requires a highly sensitive detection method. Although different tests already exist for the detection of RSV, reverse transcription-polymerase chain reaction (RT-PCR) has been shown to have the best sensitivity. In this study, a SYBR Green assay was established for the detection of RSV A and RSV B in a common screening test, and two quantitative TaqMan RT-PCRs were developed to quantify both RSV subgroups separately. Standard dilutions obtained from RSV cell infections were included in each test, and the assay was normalised using a housekeeping gene. RSV was found in 16% of the transplanted patients tested. The quantitative TaqMan assay is fast, reproducible, specific and very sensitive, and could facilitate considerably the detection of RSV virus. This would in-turn facilitate studies on the role of RSV in graft rejection.

Carcinoma arising in congenital lung cysts

We report on a patient presenting with a bronchioloalveolar carcinoma fortuitously detected in the wall of a bronchogenic cyst. Evidence suggests that unstable epithelial cells contained within the cyst wall may lead to premalignant proliferation and neoplasia. In the current case, we demonstrated an increased proliferative activity in some areas of the cyst consistent with atypical adenomatous hyperplasia. Hence, we stress the importance of close follow-up of all suspected congenital lung cysts because of their potential malignant degeneration.

Short- and long-term results of total vs subtotal thyroidectomies in the surgical treatment of Graves' disease

OBJECTIVE

Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease.

METHODS

From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue--mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery.

RESULTS

There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT--with follow-ups averaging two years (0.5-8)--are receiving thyroxin substitution.

CONCLUSIONS

There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

Role of the distal balloon protection technique in the prevention of cerebral embolic events during carotid stent placement

BACKGROUND AND PURPOSE

We sought to quantitatively and qualitatively evaluate the release of atheromatous plaque debris induced by carotid stenting procedures.

METHODS

Eight patients with severe carotid atheromatous stenoses were treated by stent implantation under distal balloon protection. Blood samplings were obtained after stent deployment in the blood pooled below the inflated protection balloon. The samples were centrifuged and evaluated for plaque debris with the use of light microscopy. The debris release was quantitatively estimated by dividing the total volume of debris obtained by the mean debris size. Five patients without endovascular procedure were used as a control group.

RESULTS

The 2 main debris types found were nonrefringent cholesterol crystals (4 to 389 microm; 115 to 8697 in number) and lipoid masses (7 to 600 microm; 341 to 34 000 in number). There was a statistically significant difference compared with the samples obtained in the control group (P:=0.017).

CONCLUSIONS

Blood samples collected during stent implantation procedures contain a large quantity of atheromatous plaque debris. This emphasizes the role of distal protection techniques in avoiding migration of this plaque material into the cerebral circulation.

Fungal infections in transplant recipients

Fungi are ubiquitous and the respiratory tract is exposed to aerosolized spores of both fungi that are "pathogenic" even in the normal host, such as Cryptococus neoformans, and those that are "opportunistic", such as Candida and Aspergillus species, among others. Although these latter species may occasionally form fungal balls or induce allergic phenomena in the normal host, they produce more invasive diseases in immunosuppressed patients. Among these diseases, pseudomembranous aspergillosis has recently been described. The diagnostic approach to these entities, and, in particular, the thin dividing line between colonization and infection are addressed, along with the diagnostic value of the various procedures. New prophylactic regimens are reviewed such as the possibility of using amphotericin aerosols in combination with systemic azole administration. The authors would emphasize the importance of restoring lung defences by not only decreasing immunosuppressive regimens but also considering the use of newly available recombinant cytokines such as growth factors, to reduce neutropenia, for instance, in addition to antifungal drugs when infection is diagnosed. However, immunomodulation procedures are far from being well established.

Matrix metalloproteinases correlate with alveolar-capillary permeability alteration in lung ischemia-reperfusion injury

BACKGROUND

Matrix metalloproteinases (MMPs) are able to degrade the endothelial basal lamina and increase vascular permeability.

METHODS

In a porcine model of isolated-reperfused lung, we studied the alveolar-capillary permeability and the zymographic expression of MMP-9 and MMP-2 in the bronchoalveolar lavage fluid of lungs submitted ex vivo to ischemia in three preservation solutions [modified Euro-Collins (EC), low-potassium-dextran, modified-blood]. Twenty-two pigs were randomly divided into three groups according to the preservation solution used. One lung of each pig was rapidly reperfused and analyzed (control lung) although the other lung was reperfused and analyzed after 8 hr of ischemia (ischemic lung).

RESULTS

Alveolar-capillary permeability, evaluated by the transferrin leak index, was increased after 8 hr of ischemia compared with controls in the three groups, but was significantly higher in the modified EC group. In the EC group, after 8 hr of ischemia, both proMMP-9 and MMP-9 increased significantly (8.8- and 22-fold, respectively) compared with controls and this increase correlated with the transferrin leak index. Neither proMMP-9 nor MMP-9 increased with the other two preservation solutions. The MMP-2 increase after ischemia was smaller and was also restricted to the EC group.

CONCLUSION

MMP expression is enhanced during lung ischemia-reperfusion, especially in the presence of EC and this phenomenon correlates with the alteration of alveolar-capillary permeability.

Systemic pulmonary artery shunt using a bovine mesenteric venous graft in newborns

A new bovine mesenteric venous graft 3 or 4 mm in diameter was used for performing systemic pulmonary artery shunts in six cyanotic newborns (aged 2 to 30 days) from March 1997 onward. Clinical and echocardiographic studies proved that all shunts were patent and functioning well after an average of 8.8 months despite no postoperative anticoagulation or antiplatelet regimen. Histological examination of two grafts explanted at the time of bidirectional cavopulmonary anastomosis showed no dense fibrotic mural infiltration, calcification, or anastomotic hyperplasia. Bovine mesenteric venous grafts can be used for the construction of systemic pulmonary artery shunts with advantages similar to that of human vein allografts, such as the facility of implantation, good short- and mid-term patency, easy takedown, and avoidance of complications presumably specific to polytetrafluoroethylene.

Lung recruitment and lung volume maintenance: a strategy for improving oxygenation and preventing lung injury during both conventional mechanical ventilation and high-frequency oscillation

OBJECTIVE

To determine whether using a small tidal volume (5 ml/kg) ventilation following sustained inflation with positive endexpiratory pressure (PEEP) set above the critical closing pressure (CCP) allows oxygenation equally well and induces as little lung damage as high-frequency oscillation following sustained inflation with a continuous distending pressure (CDP) slightly above the CCP of the lung.

MATERIAL AND METHODS

Twelve surfactant-depleted adult New Zealand rabbits were ventilated for 4 h after being randomly assigned to one of two groups: group 1, conventional mechanical ventilation, tidal volume 5 ml/kg, sustained inflation followed by PEEP > CCP; group 2, high-frequency oscillation, sustained inflation followed by CDP > CCP.

RESULTS

In both groups oxygenation improved substantially after sustained inflation (P < 0.05) and remained stable over 4 h of ventilation without any differences between the groups. Histologically, both groups showed only little airway injury to bronchioles, alveolar ducts, and alveolar airspace, with no difference between the two groups. Myeloperoxidase content in homogenized lung tissue, as a marker of leukocyte infiltration, was equivalent in the two groups.

CONCLUSIONS

We conclude that a volume recruitment strategy during small tidal volume ventilation and maintaining lung volumes above lung closing is as protective as that of high-frequency oscillation at similar lung volumes in this model of lung injury

Keratinocyte growth factor protects alveolar epithelium and endothelium from oxygen-induced injury in mice

Keratinocyte growth factor (KGF) has been used successfully to prevent alveolar damage induced by oxygen exposure in rodents. However, this treatment was used intratracheally and before oxygen exposure, which limited its clinical application. In the present study, mice were treated with the recombinant human KGF intravenously before (days -2 and -1) or during (days 0 and +1) oxygen exposure. In both cases, lung damage was attenuated. KGF increased the number of cells incorporating bromodeoxyuridine (BrdU) in the septa and in bronchial epithelium of air-breathing mice but not of oxygen-exposed mice, indicating that the protective effect of KGF is not necessarily associated with proliferation. Oxygen-induced damage of alveolar epithelium and, unexpectedly, of endothelium was prevented by KGF treatment as seen by electron microscopy. We investigated the effect of KGF on different mechanisms known to be involved in oxygen toxicity. The induction of p53, Bax, and Bcl-x mRNAs during hyperoxia was to a large extent prevented by KGF. Surfactant proteins A and B mRNAs were not markedly modified by KGF. The anti-fibrinolytic activity observed in the alveoli during hyperoxia was to a large extent prevented by KGF, most probably by suppressing the expression of plasminogen activator inhibitor-1 (PAI-1) mRNA and protein. As PAI-1 -/- mice are more resistant to hyperoxia, KGF might act, at least in part, by decreasing the expression of this protease inhibitor and by restoring the fibrinolytic activity into the lungs.

Physiological changes in respiratory function associated with ageing

Physiological ageing of the lung is associated with dilatation of alveoli, enlargement of airspaces, decrease in exchange surface area and loss of supporting tissue for peripheral airways ("senile emphysema"), changes resulting in decreased static elastic recoil of the lung and increased residual volume and functional residual capacity. Compliance of the chest wall diminishes, thereby increasing work of breathing when compared with younger subjects. Respiratory muscle strength also decreases with ageing, and is strongly correlated with nutritional status and cardiac index. Expiratory flow rates decrease with a characteristic alteration in the flow-volume curve suggesting small airway disease. The ventilation-perfusion ratio (V'A/Q') heterogeneity increases, with low V'A/Q' zones appearing as a result of premature closing of dependent airways. Carbon monoxide transfer decreases with age, reflecting mainly a loss of surface area. In spite of these changes, the respiratory system remains capable of maintaining adequate gas exchange at rest and during exertion during the entire lifespan, with only a slight decrease in arterial oxygen tension, and no significant change in arterial carbon dioxide tension. Ageing tends to diminish the reserve of the respiratory system in cases of acute disease. Decreased sensitivity of respiratory centres to hypoxia or hypercapnia results in a diminished ventilatory response in cases of heart failure, infection or aggravated airway obstruction. Furthermore, decreased perception bronchoconstriction and diminished physical activity may result in lesser awareness of the disease and delayed diagnosis.

Myofibroblasts in diffuse alveolar damage of the lung

The myofibroblast is an ultrastructurally and metabolically distinctive connective tissue cell identified as a key participant in tissue remodeling in human granulation tissue, organ fibrosis, and the fibroblastic host response to malignant neoplasms. In this study of myofibroblasts in human lung diffuse alveolar damage (DAD), we identified 36 autopsy cases in which DAD could be histologically documented. DAD is known to progress from initial injury through an exudative, proliferative, and terminal fibrotic phase. In the exudative phase (16 cases), myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA) are found in the septa and less frequently in hyaline membranes. In the proliferative phase (18 cases), many myofibroblasts in septa, hyaline membranes, and intra-alveolar fibroplasia express alpha-SMA. The alpha-SMA phenotype should be used in additional studies of myofibroblast differentiation, replication, and apoptosis. A better understanding of the biology of this cell type should offer new therapy for patients with DAD.

Increased epidermal growth factor-receptor protein in a human mesothelial cell line in response to long asbestos fibers

Epidermal growth factor (EGF) is a potent mitogen for human mesothelial cells, and autophosphorylation of the EGF receptor (EGF-R) occurs in these cell types after exposure to asbestos, a carcinogen associated with the development of mesothelioma. Here, the intensity and distribution of EGF-R protein was documented by immunocytochemistry in a human mesothelial cell line (MET5A) exposed to various concentrations of crocidolite asbestos and man-made vitreous fibers (MMVF-10). Whereas cells in contact with or phagocytizing shorter asbestos fibers (<60 microm length) or MMVF-10 at a range of concentrations showed no increase in EGF-R protein as determined by immunofluorescence, elongated cells phagocytizing and surrounding longer fibers (> or =60 microm) showed intense staining for EGF-R. In contrast, human A549 lung carcinoma cells showed neither elongation nor increased accumulation of EGF-R protein in response to long fibers. Patterns of aggregation and increases in EGF-R protein in mesothelial cells phagocytizing long asbestos fibers were distinct from diffuse staining of phosphotyrosine residues observed in asbestos-exposed cultures. These studies indicate that aggregation of EGF-R by long fibers may initiate cell signaling cascades important in asbestos-induced mitogenesis and carcinogenesis.

Cytoskeletal protein modulation in pulmonary alveolar myofibroblasts during idiopathic pulmonary fibrosis. Possible role of transforming growth factor beta and tumor necrosis factor alpha

Pulmonary biopsy specimens from ten cases of idiopathic pulmonary fibrosis (IPF) were examined using routine histological stains, including toluidine blue, and immunohistochemistry by means of specific antibodies against alpha-smooth muscle (alpha-SM) actin, desmin, keratin, TGF beta 1, and TNF alpha. The sections were compared with two cases of normal lung. As shown previously, normal alveolar interstitium did not contain alpha-SM actin positive myofibroblasts nor did the alveolar lining contain any significant number of TGF beta 1 or TNF alpha laden epithelial cells. In IPF, during the inflammatory stage, the alveolar myofibroblasts expressed alpha-SM actin and the regenerating type II alveolar epithelium staining strongly with TGF beta 1 and TNF alpha antibodies. The former cytokine was also detected in the interstitial matrix and fibroblastic cells as well as in the wall of vessels. At this stage, a manifest mast cell infiltration was noted. In very fibrotic and cystic alveolar tissue, i.e., at end stage fibrosis, the number of alpha-SM actin positive myofibroblasts as well as that of TNF alpha laden type II epithelial cells diminished, while TGF beta 1 positive cells persisted. Our findings demonstrate that during IPF alveolar type II epithelium constitutes, if not the site of synthesis, at least the main reservoir for TGF beta 1 and TNF alpha. These cytokines, besides their involvement in fibrogenesis, play probably an important role in the expression of alpha-SM actin by alveolar myofibroblasts. Our study suggests the possibility of an interaction between interstitial cells and alveolar epithelium, during IPF.

Undifferentiated carcinoma of the gallbladder. Report of a case with immunohistochemical findings

One case of undifferentiated carcinoma of the gallbladder was studied using an extensive immunohistochemical panel of antibodies. The biphasic differentiation of the tumor was highlighted by different immunoreactivity to antibodies against cytokeratins, vimentin, epithelial membrane antigen, and carcinoembryonic antigen of the adenocarcinomatous and mesenchymallike components, although the latter showed a faint positivity for CAM5.2 antibody, probably indicating an epithelial origin. Furthermore, the higher levels of expression of p53 protein and the faster growth rate in the pseudosarcomatous component suggest its more malignant phenotype. The relationship with "true" carcinosarcomas of the gallbladder and the histogenetic theories concerning these tumors are also discussed.

A thymoma as a cause of true ectopic hyperparathyroidism

Ectopic tumoral secretion of authentic PTH is rare, as only four cases have been convincingly documented by demonstrating the presence of PTH messenger ribonucleic acid in tumor tissue. We report the case of a 25-yr-old male with biochemical alterations typical of primary hyperparathyroidism (elevated calcemia and renal tubular reabsorption of calcium, decreased phosphatemia and maximal tubular reabsorption of phosphate, and increased intact PTH serum levels). Extensive cervical exploration did not reveal any abnormally enlarged parathyroid tissue, but excision of a palpable superior retrosternal mass led to the correction of all abnormal biochemical values. Histological analysis showed a predominantly epithelial thymoma, without any detectable parathyroid gland on serial slices. Tumor extracts contained immunoreactive PTH material, with serial dilutions paralleling PTH standards in an immunoradiometric assay. By contrast, immunoreactive PTH-related protein was absent. Furthermore, on Northern blot analysis, there was a PTH messenger ribonucleic acid transcript with a size similar to that found in parathyroid adenoma or hyperplasia. The thymoma epithelial cells stained positively with antiserum against PTH-(1-34), but negatively with antichromogranin-A antiserum. These results support the ectopic production of authentic PTH by a thymoma and indicate a novel tumoral cause of primary hyperparathyroidism.

Vertical LM sectioning and parallel CT scanning designs for stereology: application to human lung

Practical, unbiased stereological methods are described to estimate lung volume and external surface area, and total volume and surface area of relatively large and anisotropic structures (bronchi and arteries) inside the lung. The volume of each of five lung strata was estimated first by fluid displacement and then by computed tomography (CT) using Cavalieri's method; the reliability of CT was assessed through a calibration procedure, and image thresholding criteria for an accurate volume estimation using CT were established. The parallel, perfectly registered CT section images were also used to estimate the external surface area of each stratum by the spatial grid method. Unbiased estimation of internal surface areas in lung is a long-standing problem: since the structures are large and essentially void, large sections are needed; to facilitate identification, thin sections have to be used for light microscopy, and since such structures are anisotropic, the sections should be vertical. A practical stereological design is demonstrated here on an infant lung, which fulfils all these requirements. This study illustrates the potential of using unbiased stereology to characterize infant pulmonary hypoplasia.

[Reliability of bronchial tumor typing base on fibroscopically obtained biopsies]

This study is based on the bronchial tumors biopsied and later examined between 1971 and 1986 at the Institute of Pathology, Lausanne. In each case the diagnosis based on the initial biopsy material is compared with the final surgical or autopsy diagnosis (Reference: Histological typing of lung tumours, second edition, WHO, 1981, 2). The series studied is constituted by 163 cases: 144 men (88.3%) and 19 women (11.7%). In 136 cases (83.4%), the biopsy diagnoses are identical to the diagnoses based upon surgical or autopsy material; in 27 cases (16.6%) these diagnoses differ. The positive predictive value of bronchial biopsy appears to be excellent (100%) for small cell and epidermoid carcinoma (CA). It is satisfactory for adenocarcinoma (85.7%) but insufficient for large cell CA (42.3%) and the tumors grouped under "others" (50%). The diagnosis of large cell CA, in situ CA, papillary tumor, undifferentiated CA, or carcinomatous lymphangitis should be considered with caution and in some cases it is advisable to repeat the biopsy. The discrepancies between the initial and final diagnoses can, in all cases, be attributed either to the biopsy specimen being too small and therefore nonrepresentative or, less frequently, to crushing and necrosis of the tissues.