Primary pleural neoplasia: entities other than diffuse malignant mesothelioma

Liposarcoma of the pleural cavity

Liposarcoma rarely occurs in the pleura or thoracic cavity, and few reports appear in the literature. We hypothesized that combining clinicopathologic, immunohistochemical, and fluorescence in situ hybridization methods would allow definite diagnoses. Using formalin-fixed, paraffin-embedded blocks, we examined 6 atypical lipomatous tumor/well-differentiated types (ALT/WDLPS), 5 dedifferentiated types (DDLPS), 2 pleomorphic types, and 1 myxoid type (MLSP). We used the Kaplan-Meier method and the Wilcoxon test for survival analysis for prognostic factor evaluation. Histologically, ALT/WDLPS was composed of a relatively mature adipocytic proliferation, accompanied by some lipoblasts. DDLPS exhibited round-to-oval tumor cells with a high nucleus-to-cytoplasm ratio that had proliferated in nests, accompanied in case 10 by some giant cells but no fatty cells. The pleomorphic type contained a varying proportion of pleomorphic lipoblasts. MLSP displayed uniform round to oval-shaped cells and small signet-ring lipoblasts in a myxoid stroma. Immunohistochemically, 11 (79%), 11 (79%), and 10 (71%) of 14 cases were positive for S-100, p16, and CDK4, respectively. Six (43%) of the 14 cases were positive for MDM2, and adipophilin. One case of ALT/WDLPS and 3 cases of DDLPS exhibited MDM2 amplification by fluorescence in situ hybridization (Vysis LSI MDM2 SpectrumGreen Probe plus Vysis CEP 12 SpectrumOrange probe). ALN/WDLPS was the most favorable type for survival, while adipophilin tended to be a negative prognostic factor for pleural liposarcoma. For a firm diagnosis of liposarcoma in the pleura, immunohistochemistry for CDK4, MDM2, and adipophilin together with MDM2 gene amplification by fluorescence in situ hybridization may be an important diagnostic tool.

Radical extrapleural pneumonectomy with bronchial fistula by pulmonary function test evaluation technique

Introduction

and importance: Pulmonary Function Tests (PFTS) is an important tool in the assessment of pulmonary pathologies and preoperative evaluation. Case presentation: A 54-year-old man with history of massive pleurisy in the left thorax, treated by placing chest tube and drainage of bloody effusion, was readmitted for epithelioid mesothelioma. He was then presented with pneumothorax due by a refractory bronchial fistula while having a plural catheter. Based on the consultation, the whole-body bone scan was conducted, and findings demonstrated epithelioid mesothelioma (stage 1) with the refractory fistula for which the patient was candidate for thoracic surgery. Decreased lung capacity was seen by Pulmonary Function Testing - PFTS.

Clinical discussion

The novel PFTS Evaluation Technique was designed to measure the true pulmonary capacities in order to evaluate the pulmonary post-operative tolerance. In this technique the chest tube was placed for 4 weeks until the patient reaches mediastinal fixation then the measurements by PFTS were carried out in two steps. First, using an open chest tube and second, using a clamped chest tube. In both steps, the pulmonary capacities were measured and provided to the pulmonologist for consultation.

Conclusion

In this case, after acquiring the approval of the specialist depended on PFTS after PFTS Evaluation Technique, the radical extra pleural pneumonectomy surgery was conducted, and the patient was discharged with a good general appearance and treated fistula.

Position Paper on Asbestos of the Italian Society of Occupational Medicine

The Position Paper (PP) on asbestos of the Italian Society of Occupational Medicine (SIML) aims at providing a tool to the occupational physician to address current diagnostic criteria and results of epidemiological studies, and their consequences in terms of preventive and evaluation actions for insurance, compensation and litigation. The PP was based on an extensive review of the scientific literature and was compiled by a Working Group comprising researchers who have contributed to the international literature on asbestos-related diseases, as well as occupational physicians with extensive experience in the evaluation of risks and the medical surveillance of workers currently and formerly exposed to asbestos. The PP was drafted and reviewed between 2017 and 2018; its final version was prepared according to the guidelines of AGREE Reporting Checklist. All the members of the Working Group subscribed to the document, which was eventually approved by SIML's Executive Committee. The first section addresses industrial hygiene issues, such as methods for environmental monitoring, advantages and limitations of different microscopy techniques, the potential role of microfibers and approaches for retrospective assessment of exposure, in particular in epidemiological studies. The second section reviews the biological effects of asbestos with particular attention to the diagnostic aspects of asbestosis, pleural changes, mesothelioma and lung cancer. In the following section the criteria of causal attribution are discussed, together with different hypotheses on the form of the risk functions, with a comparison of the opinions prevalent in the literature. In particular, the models of the risk function for mesothelioma were examined, in the light of the hypothesis of an acceleration or anticipation of the events in relation to the dose. The last section discusses topics of immediate relevance for the occupational physician, such as health surveillance of former exposed and of workers currently exposed in remediation activities.

The Diagnosis of Pleural Tumors Other Than Mesothelioma

CONTEXT

- Pleural pathology has been dominated by discussions relating to the diagnosis, prognosis, etiology, and management of malignant mesothelioma. However, there exists a diverse group of other neoplasms that involve the pleura; the most common by far is metastatic carcinoma, usually of pulmonary origin. Other metastatic tumors of varied histogenesis do occur but are less common. Primary pleural neoplasms other than diffuse malignant mesothelioma are either uncommon or rare and have received less attention.

OBJECTIVE

- To provide a review of those diverse tumors that can involve the pleura other than mesothelioma in order to facilitate their accurate diagnosis.

DATA SOURCES

- Review of relevant literature published via PubMed and other search engines.

CONCLUSIONS

- A wide variety of tumors can involve the pleura. In most cases, the approach of considering the morphologic features with appropriate immunohistochemistry, in the correct clinical context, allows for a confident diagnosis. For a number of those soft tissue tumors that are well recognized in the pleura, such as solitary fibrous tumor, desmoid-type fibromatosis, synovial sarcoma, and epithelioid hemangioendothelioma, novel markers now exist based on an understanding of the individual tumors' molecular characteristics. Primary pleural lymphomas are rare with poor prognosis. They represent localized specific diffuse large B-cell lymphomas, with either post-germinal center B-cell or plasma cell lineage, arising in the context of either immunodeficiency or immune sequestration and with viral infection.

Magnetic resonance features of meningeal solitary fibrous tumors

The aim of the present study was to investigate magnetic resonance (MR) features of meningeal solitary fibrous tumors (SFTs) in order to improve their recognition. The study retrospectively analyzed MR manifestations in 12 cases of meningeal SFTs confirmed by surgery. The lesions were analyzed in terms of the site of their growth, growth mode, morphology, size, changes in the MR signal and the edge of the focus. The tumors were malignant in 3 cases, benign in 7 cases and borderline in 2 cases. A total of 3 cases spanned the tentorium cerebelli, 3 spanned the falx and another case was close to the falx. Overall, 4 superficial tumors were accompanied by adjacent bony destruction. One case was located at the triangular area created by the right lateral ventricles. The tumors were all lobular, with a large diameter and more cystic areas in the center of the focus. The signals were often heterogeneous. The parenchyma in the tumors was significantly enhanced. For certain tumors, the signal was usually inhomogeneous and not uniform. The MR features of a SFT were often similar to other intracranial tumors and easily misdiagnosed. There were certain innate characteristics, for example, the tumor was often a solitary large soft-tissue mass with an irregular edge and a clear boundary, with a lobulated contour, and was widely involved with other tissues. The tumors often grew across either the falx or tentorium cerebelli. A significantly inhomogeneous signal was found and either a low or low-high mixed signal on T2-weighted images in particular. These features are useful for the differential diagnosis of SFTs and other tumors.

Diagnosis of desmoplastic small-round-cell tumor by cytogenetic analysis: a case report

We herein present atypical histologic and immunohistochemical features of DSRCT. The various differential diagnoses of DSRCT may occasionally generate confusion. Cytogenetic analysis may solve diagnostic dilemmas such as that in our case. Further studies are required to establish a standard treatment for DSRCT.

Medicolegal Aspects of Asbestos I — Malignant Mesothelioma and Lung Cancer

Inhalation of asbestos fibers can cause a variety of conditions, benign and malignant, of the lungs and pleura. Illnesses and deaths in which asbestos may have had a causal or contributory role are often the subject of litigation. Forensic pathologists (FP) can become involved in some of these cases in their capacity of a medical examiner or coroner, autopsy pathologist or as an expert retained by one or more parties involved in litigation. FP input may be sought to address issues such as diagnosis, assessment of exposure, and attribution. This review will discuss medicolegal issues that surround lung and mesothelial tumors that can be caused by the inhalation of asbestos fibers.

Pathohistological diagnosis and differential diagnosis

Malignant mesothelioma is a rare aggressive tumour arising from mesothelial cells of the pleural and peritoneal cavity including pericardium and tunica vaginalis testis. Malignant mesothelioma occurs predominantly in men (>90%). Asbestos exposure is the best known and evaluated risk factor with a long latency period between exposure and onset of malignant mesothelioma ranging from 15 to 60 years. Exposure to erionite leads to higher incidences of mesothelioma and play an important role in environmental exposure (Turkey). Other possible risk factors are radiation, recurrent pleuritis/peritonitis and simian virus 40 (SV 40).Malignant pleural mesothelioma is most common, whereas malignant peritoneal mesothelioma accounts only for 6-10%. Infrequent sites of origin are the pericardium and tunica vaginalis in 1-2%.Malignant mesothelioma shows either diffuse growth pattern or occurs as a localised tumour mass. Diffuse type represents an aggressive tumour with poor prognosis and is incurable in most cases.According to the WHO classification, three histological subtypes are distinguished: epithelioid, sarcomatoid and biphasic malignant mesothelioma.Rare variants are desmoplastic type, a subtype of sarcomatoid mesothelioma, undifferentiated type and deciduoid type. Epithelioid type is the most frequent one, but biphasic malignant mesothelioma occurs in 30%. Pure sarcomatoid or biphasic type is seen less frequently in malignant peritoneal mesothelioma than in its pleural counterpart.Well-differentiated papillary mesothelioma is a generally non-invasive mesothelioma with low malignant potential that arises mostly in females in the peritoneal cavity. Histological type is an important prognostic marker. Longest survival is seen in patients with epithelioid malignant mesothelioma. Sarcomatoid subtype has the worst prognosis.Malignant mesothelioma shows macroscopical and microscopical similarities to benign lesions and other malignancies. Therefore, reactive mesothelial proliferations on the one hand and secondary tumours resembling mesothelial cells as well as benign or rare mesothelial tumours on the other hand have to be distinguished. Additional immunohistochemistry is essential in histopathological assessment using a marker panel of antibodies.