EGFR and PDGFR differentially promote growth in malignant epithelioid mesothelioma of short and long term survivors.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an asbestos related tumour difficult to detect early and treat effectively. Asbestos causes genetic modifications and cell signalling events that favour the resistance of MPM to apoptosis and chemotherapy. Only a small number of patients, approximately 10%, survive more than 3 years. The aim of our study was to assess possible differences within signalling pathways between short term survivors (survival <3 years; STS) and long term survivors (survival >3 years; LTS) of MPM. METHODS: 37 antibodies detecting proteins engaged in cell signalling pathways, enforcing proliferation, antiapoptosis, angiogenesis and other cellular activities were investigated by tissue microarray (TMA) technology. RESULTS: Epidermal growth factor receptor (EGFR) was expressed stronger in LTS whereas platelet derived growth factor receptor (PDGFR) signalling was more abundant in STS. Expression of TIE2/Tek, a receptor for tyrosine kinases involved in angiogenesis, was differentially regulated via PDGFR and thus is more important in STS. Antiapoptosis was upregulated in STS by signal transducer and activator of transcription 1 (STAT1)-survivin and related molecules, but not in LTS. Our study provides novel insights into the regulatory mechanisms of signalling pathways in MPM, which differentially promote tumour growth in LTS and STS. CONCLUSION: We have demonstrated that small scale proteomics can be carried out by powerful linkage of TMA, immunohistochemistry and statistical methods to identify proteins which might be relevant targets for therapeutic intervention.

Adenocarcinoma classification: patterns and prognosis.

Lung cancer is the most frequent human malignancy and the principal cause of cancer-related death worldwide. Adenocarcinoma is now the main histologic type, accounting for almost half of all the cases. The 2015 World Health Organization has adopted the classification recently developed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification has incorporated up-to-date advances in radiological, molecular and oncological knowledge, providing univocal diagnostic criteria and terminology. For resection specimens, new entities have been defined such as adenocarcinoma in situ and minimally invasive adenocarcinoma to designate adenocarcinomas, mostly nonmucinous and ≤ 3 cm in size, with either pure lepidic growth or predominant lepidic growth with ≤ 5 mm invasion, respectively. For invasive adenocarcinoma, the new classification has introduced histological subtyping according to the predominant pattern of growth of the neoplastic cells: lepidic (formerly non mucinous brochioloalveolar adenocarcinoma), acinar, papillary, micropapillary, and solid. Of note, micropapillary pattern is a brand new histologic subtype. In addition, four variants of invasive adenocarcinoma are recognized, namely invasive mucinous (formerly mucinous brochioloalveolar adenocarcinoma), colloid, fetal, and enteric. Importantly, three variants that were considered in the previous classification have been eliminated, specifically mucinous cystadenocarcinoma, signet ring cell, and clear cell adenocarcinoma. This review presents the changes introduced by the current histological classification of lung adenocarcinoma and its prognostic implications.

Primary resistance to osimertinib due to SCLC transformation: Issue of T790M determination on liquid re-biopsy.

OBJECTIVES: EGFR T790M mutation is the most common mechanism of resistance to first-/second-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) and could be overcome by third-generation EGFR-TKIs, such as osimertinib. Liquid biopsy, a non-invasive technique used to test the presence of the resistant mutation, may help avoiding tissue re-biopsy. However, analysing only circulating-free DNA, information about other less frequent and coexisting resistance mechanisms may remain unrevealed. MATERIALS AND METHODS: All patients reported in this series participated in the ASTRIS trial, a real world treatment study testing the efficacy of osimertinib (80mg os die) in advanced T790M-positive NSCLC progressed to prior EGFR-TKI. Patients were considered eligible to osimertinib if T790M positive on tissue or plasma samples. In our patients, EGFR molecular testing on blood sample was conducted with digital droplet PCR (ddPCR). RESULTS: We report our experience of five patients treated with osimertinib after T790M detection on liquid biopsy that presented a disease progression at first tumor assessment mediated by SCLC transformation, as evidenced at tissue re-biopsies. All patients showed low ratio T790M/activating mutation in the blood before osimertinib (lower than 0.03). For three patients, EGFR mutational analysis was T790M-negative when re-assessed by using a less sensitive method (therascreen®) on the same liquid biopsy sample analysed by ddPCR before osimertinib therapy. CONCLUSION: Although liquid biopsy is a relevant tool to diagnose T790M presence in NSCLC patients resistant to EGFR-TKI, in case of a low ratio T790M/activating mutation, tissue biopsy should be considered to exclude the presence of SCLC transformation and/or other concomitant resistance mechanisms.

Gender differences in non-small cell lung cancer: a population-based study.

BACKGROUND: A retrospective study including all patients with non-small cell lung cancer carcinoma in a population-based registry was performed to characterize gender differences in lung cancer and to analyze the factors influencing prognosis in women. METHODS: We retrieved through the Tuscan Cancer Registry (RTT) archive 2,523 lung tumor cases diagnosed during the period 1996-1998 in the provinces of Florence and Prato, central Italy. We compared the prognosis within 464 non-small lung cancer women and 1,798 men in a population-based case series. The influence of the following variables on postoperative survival were analyzed: age, cell type, pathologic T and N status, site of tumor and type of surgical resection. RESULTS: The age at diagnosis was similar in women and in men. Women were significantly more likely to have adenocarcinoma but less likely to have squamous cell carcinoma compared with men. Fewer pneumonectomies were performed in women than in men. Nevertheless, prognosis was similar in both sexes and type of surgical resection was significant prognostic factor. CONCLUSIONS: Lung cancer was more frequent in men than in women, but overall survival is similar. Differences in lung cancer histology and rate of pneumonectomies were found between men and women.

Calretinin, thrombomodulin, CEA, and CD15: a useful combination of immunohistochemical markers for differentiating pleural epithelial mesothelioma from peripheral pulmonary adenocarcinoma.

The distinction between pleural epithelial mesothelioma and peripheral lung adenocarcinoma involving the pleura is still an important diagnostic problem for surgical pathologists. The aim of our study was to identify the most specific and sensitive markers for the positive identification of mesothelioma to select a limited, appropriate panel of antibodies to differentiate between mesothelioma and adenocarcinoma. Forty-two cases of epithelial mesotheliomas and 23 cases of pulmonary adenocarcinomas were stained with the following antibodies: anticalretinin, antithrombomodulin, anti-CD44H, and monoclonal antibody HBME-1. We also studied the value of other markers in current use: cytokeratins AE1/AE3 and CAM5.2, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Ber-EP4, B72.3, and CD15. Of the mesotheliomas, 42 stained for calretinin, 39 (92.8%) for thrombomodulin, 42 stained for CD44H, and 41 (97.6%) stained for HBME-1. Among negative markers, 4 (9.5%) mesothelioma cases stained for CEA, 5 (11.9%) stained for Ber-EP4, 6 (14.2%) stained for B72.3, and 2 (4.7%) stained for CD15. Of the lung adenocarcinomas, 2 (8.7%) cases showed reactivity for calretinin, 5 (21.7%) for thrombomodulin, 13 (56.5%) for CD44H, all for HBME-1, 22 (95.6%) for CEA, 22 (95.6%) for Ber-EP4, 8 (34.7%) for B72.3, and all for CD15. In conclusion, calretinin and thrombomodulin were the most specific positive mesothelial markers, whereas CD44H and HBME-1 showed high sensitivity but very low specificity. Among negative markers, we advocate the use of CEA and CD15 which were the most specific in differentiating mesotheliomas from adenocarcinomas.

Microvessel density and clinicopathological characteristics in hepatitis C virus and hepatitis B virus related hepatocellular carcinoma.

AIMS: To compare intratumorous microvessel density (MVD) and clinicopathological features in two different groups of hepatocellular carcinoma (HCC), namely: hepatitis B virus (HBV) related HCC (B-HCC) and HCV related HCC (C-HCC). METHODS: Fifty consecutive cases each of B-HCC and of C-HCC were studied. Microvessel numbers were assessed by staining for the antigen CD34; in each case, three areas with the highest numbers of microvessels were counted in both the intratumorous and the surrounding non-tumorous tissue; the mean value represented the final MVD. RESULTS: Patients with B-HCC were significantly younger than those with C-HCC (mean age, 60.1 (SD, 4.1) v 66.4 (4.3) years); no significant differences were seen for sex or Child's class distribution. The tumour diameter was larger in B-HCCs than in C-HCCs (mean, 5.6 (SD, 1.8) v 3.8 (1.8) cm). Tumour microsatellite formation was significantly higher in C-HCCs (12 v 4 cases). No differences were found for histological subtype, degree of differentiation, tumour encapsulation, and vascular invasion. The mean MVD value was significantly higher in tumorous (mean, 54 (SD, 13.8) v 38 (8.9)) and in the surrounding non-tumorous liver tissue (mean, 15 (SD, 4.3) v 7 (3.1)) of C-HCCs. CONCLUSIONS: C-HCCs present as smaller tumours in older patients, with a higher incidence of tumour microsatellite formation and higher MVD values both in the tumorous and the non-tumorous areas, suggesting a link between HCV infection, angiogenesis, and hepatocarcinogenesis.

Oxyphil cell adenoma (oncocytoma) of the lacrimal caruncle: a case report.

The onset of oncocytic neoplasms in the ocular area is exceptional. A rare case of oxyphil cell adenoma of the lacrimal caruncle in an 81-year-old woman is presented. The anatomo-clinical profile of this benign small tumor is drawn up: a slowly growing tumor, generally occurring in the caruncle of elderly women, which is characterized by a uniform population of epithelial cells with eosinophilic finely-granular cytoplasm containing large numbers of mitochondria. The histogenetic problem of this tumor is briefly discussed.

Oncocytoma of the nasal cavity: report of a case and review of the literature.

The authors present a case of oncocytoma of the nasal cavity in a 60-year-old woman. The tumour shows the same histological and ultrastructural characteristics of oncocytomas arising in minor salivary glands of other sites and major salivary glands. The authors stress that the biological behaviour of oncocytomas of the nasal cavity seems related to their local growth rather than to the cytological characteristics of the tumour. The extreme rarity of this tumour in the nasal cavity is particularly emphasized. The few cases reported previously in literature are briefly reviewed.

[Isosporiasis and sarcocystosis. The current findings]. / Isosporiasi e sarcocistosi. Acquisizioni attuali.

A review on infections by Isospora belli and Sarcocystis spp. both in healthy and in AIDS patients is done on the basis of literature and personal data. In this view a special focus is made on isospora belli infection in AIDS because of its high recurrence after successful attack therapy. Consequently the most recent protocols for maintenance and attack therapy in these patients are reported. At the end, concerning ultrastructural pathology, the features of some Isospora belli developing stages are described by means of electron microscopy on duodenal biopsy specimens from a patient.

Mesothelioma as a risk indicator of asbestos exposure: the role of the pathologist.

Malignant mesothelioma is an uncommon tumour, which has become an important epidemiological marker for exposure to asbestos. This tumour is characterised by a wide range of microscopic features which may be classified in three histologic patterns: epithelial, mesenchimal and mixed or biphasic. Histochemical staining is often necessary to distinguish mesothelioma from carcinoma. As regards immunohistochemistry, only the use of a combination of antibodies significantly decreases the risk of false-negative results. Analytic electron microscopy techniques may also be useful, permitting the evaluation of the cumulative fiber burden in the target organ.

The use of placental S100 (S100P), GATA3 and napsin A in the differential diagnosis of primary adenocarcinoma of the bladder and bladder metastasis from adenocarcinoma of the lung.

Primary bladder adenocarcinoma accounts for 0.5-2% of all malignant bladder tumours. Literature data indicate the bladder as the second most common site of metastatic genitourinary tumours, with the kidney as the most frequent location. Secondary tumours of the bladder account for about 2.3% of all bladder malignancies encountered in surgical specimens. Herein, we describe an adenocarcinoma deeply infiltrating the bladder wall, with no morphologic features of transitional cell carcinoma, in a patient with a previous diagnosis of primary lung adenocarcinoma, mixed subtype. In this case, the use of a limited immunohistochemical panel including napsin A, a recently described highly sensitive marker for lung adenocarcinoma, GATA3 and S100P, two novel markers of urothelial differentiation, was of crucial importance in differentiating between lung adenocarcinoma metastatic to the bladder and primary bladder adenocarcinoma.

Heterogeneous expression of cyclooxygenase-2 and inducible nitric oxide synthase within colorectal tumors: correlation with tumor angiogenesis.

BACKGROUND: Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human cancers. AIMS: To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis. METHODS: Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE2 and NO at the same sites. RESULTS: COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF. CONCLUSION: Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.

EU-USA pathology panel for uniform diagnosis in randomised controlled trials for HRCT screening in lung cancer.

Randomised controlled trials for lung cancer screening using high-resolution computed tomography are now underway. In order to allow effective future comparison of the different trials, as well as strengthening conclusions based upon the analysis of larger data sets, uniformity and consistency of pathology diagnosis are essential. The aim of the present study was to determine the effectiveness of the learning process in this difficult area of diagnostic pathology. Eight pathologists received two CD-ROMs, each with digital images of 30 cases. After diagnosing the first series, selected background reading was provided. Kappa (kappa) scores were calculated for each pathologist and category, and were compared to the consensus score. The readings of the first series showed a moderate agreement kappa score: mean+/-sd for category numbers 8 (all eight categories) and 2 were 0.53+/-0.05 and 0.65+/-0.04, respectively. The kappa 2 score distinguished between categories denoting benign and malignant lesions. The second series resulted in a good agreement kappa score: 0.65+/-0.06 for category number 8 and 0.81+/-0.02 for category number 2. In conclusion, this study demonstrates that screen-detected cases pose particular problems for pathologists and that a trained pathology panel serving randomised controlled trials is likely to lead to more consistent and accurate tissue diagnosis.

Submicroscopic profile of Isospora belli enteritis in a patient with acquired immune deficiency syndrome.

Small bowel mucosal fragments from a human immunodeficiency virus-positive female patient with chronic diarrhea were investigated by transmission electron microscopy, and Isospora belli enteritis was documented. The submicroscopic profile was characterized by a moderate abnormality of mucosal architecture with reduction in height of villi and hypertrophy of crypts. Stages of both asexual (trophozoite, schizont and merozoite) and sexual (macrogametocyte) phases of the life cycle of the parasite were identified in the epithelium, always enclosed within a parasitophorous vacuole. Moreover, the presence of occasional extracellular merozoites in the intestinal lumen and in the lamina propria near or within lymphatic vessels was documented. These findings expand the current knowledge of this parasite regarding its capacity to survive in an extracellular environment and document a possible mechanism by which extraintestinal infection can take place.

[A variety of mediastinal bronchogenic cyst: the broncho-alveolar cyst]. / Varietà di cisti broncogena del mediastino: cisti bronco-alveolare.

Congenital bronchogenic cysts are usually located in the mediastinum or develop as intrapulmonary cysts. Gross examination of excised bronchogenic cysts shows them to be unilocular; histologically, these lesions are characterized by the presence of respiratory-type pseudostratified epithelium as well as small islands of cartilage and seromucinous glands. We report a case of a mediastinal bronchogenic cyst having pulmonary parenchyma within the cyst wall. The rarity of our case, the pathological and clinical features and the embryological development of bronchogenic cysts are briefly discussed.

Submicroscopic and immunohistochemical profile of surface osteosarcomas.

While the analysis of the clinical, radiologic, and histopathologic features of surface osteosarcomas has been the subject of several papers, identification of the phenotypic features of these tumors has so far received little attention. The aim of the present study was to characterize the neoplastic cells of surface osteosarcomas using an ultrastructural and immunohistochemical approach. Glutaraldehyde-fixed, epoxy resin-embedded archival pieces of tissue from 8 surface osteosarcomas (4 parosteal low-grade osteosarcomas, 3 dedifferentiated parosteal osteosarcomas, 1 periosteal osteosarcoma) were investigated using transmission electron microscopy. Sections of formalin-fixed, paraffin-embedded tumor specimens were employed for the immunohistochemical analysis of osteonectin and osteocalcin, two markers of cells of osteoblastic lineage, and sigma-smooth muscle actin and muscle specific actin. By electron microscopy, the tumors were composed of a mixture of neoplastic cells with varied differentiation, i.e., osteoblast-like, fibroblast-like, myofibroblast-like, and chondroblast-like. The latter were particularly abundant in the periosteal osteosarcoma. Osteocalcin expression was detected in the cytoplasm of neoplastic cells in 6 cases (66.6%), while osteonectin was expressed at least focally in all cases. The expression of the noncollagenous bone proteins was higher in low-grade osteosarcomas than in dedifferentiated osteosarcomas. sigma-Smooth muscle actin and muscle-specific actin expression were detected in 4 (44.4%) and 5 (55.5%) cases respectively, and the distribution was similar in both low-grade and dedifferentiated lesions. The results do not confirm previous observations regarding the prevalence of a specific cellular phenotype in surface osteosarcomas. Further, the myofibroblast-like cells that are present in variable numbers in these tumors are probably modified osteoblasts, since they co-express actin, osteonectin, and osteocalcin.

Electron Microscopy What Izzits revisited: an Ultrapath X quiz.

The authors present 18 cases of various nature, representing a wide spectrum of neoplastic and nonneoplastic diseases shown at Ultrapath X in quiz format for identification or diagnosis.