Pseudomesotheliomatous Carcinoma Research Articles

The over diagnosis of diffuse mesothelioma: An analysis of 311 cases with recommendations for the avoidance of pitfalls

BackgroundThe diagnosis of mesothelioma may be challenging. We investigated a large database of cases in order to determine the frequency with which a diagnosis of mesothelioma was made incorrectly and the most frequent causes of error. DesignA database including more than 4000 consultation cases of histologically confirmed mesothelioma was examined to identify cases in which mesothelioma was diagnosed by at least one pathologist when the available information pointed towards a different diagnosis. ResultsThere were 311 cases misdiagnosed as mesothelioma. The most common category was metastatic carcinoma to the pleura or peritoneum (129 cases: 73 lung carcinomas, 15 renal cell carcinomas). The next most common category was primary lung cancer (111 cases: 55 sarcomatoid carcinoma, 56 pseudomesotheliomatous carcinoma). The third most common category was primary malignancies arising from or near the serosal membranes (33 cases). The fourth most common category was fibrous pleurisy (38 cases). The most common errors were failure to consider important radiographic information regarding the gross distribution of tumor, lack of awareness or consideration of another malignancy, overreliance on certain immunohistochemical results, and failure to perform certain diagnostic histochemical, immunohistochemical, or ultrastructural studies. ConclusionsThere are a number of diagnostic pitfalls that can lead to the over diagnosis of mesothelioma. Careful attention to clinical and radiographic information as well as performance of appropriate ancillary tests can help to prevent such misdiagnoses. Detailed examples will be presented to assist in the avoidance of these pitfalls with emphasis on the most commonly observed errors.

Pseudocarcinomatous Mesothelioma: A Hitherto Unreported Presentation closely simulating primary lung cancer.

Malignant mesothelioma (MM) has a wide range of clinical, radiologic, and pathologic presentations, mimicking lung cancer or interstitial lung diseases when predominantly involving the lung parenchyma. The case herein refers to a 79-year-old man, active smoker without asbestos exposure, incidentally discovered to have a pulmonary nodule in the right upper lobe (1.5 cm). The lesion was misinterpreted as primary lung adenocarcinoma at the frozen section in light of the predominant lepidic growth pattern. Definitive examination confirmed neoplastic proliferation along alveolar structures. However, the unusual globous shape of tumor cells along the alveoli abruptly merging with normal pneumocytes prompted us to perform some immunostains that surprisingly revealed a mesothelial differentiation (positive staining with calretinin, cytokeratins (CK5/6), D2-40, and negativity with BRCA-associated protein 1 (BAP1), Thyroid Transcription Factor 1 [TTF-1], claudin-4, carcinoembryonic antigen [CEA], and napsin). MM represents the pathologic counterpart of so-called pseudomesotheliomatous carcinoma, since it appears as a localized pulmonary neoplastic nodule displaying a predominant lepidic growth pattern (pseudocarcinomatous mesothelioma). The challenging diagnostic features of this unique case and a review of similar cases in the literature are discussed.

P01 An Unusual Case of Pseudomesotheliomatous Carcinoma of the Lung

Pseudomesotheliomatous carcinoma of the lung is a rare entity. It has been known to mimic malignant pleural mesothelioma, clinically and pathologically. This often poses a challenge to clinicians and pathologists. We present a case of pseudomesotheliomatous carcinoma consisting of three different distinct components: namely adenocarcinoma, small cell carcinoma and sarcomatoid carcinoma components.

Lung Pseudomesothelioma in Patient with Asbestos Exposure: A Case Report

Background: Pseudomesotheliomatous carcinoma is a rare case of lung cancer with marked pleural extension resembling malignant pleural mesothelioma on diagnostic imaging. One of tool to diagnose lung pseudomesothelioma is by performing thorocoscopy pleural biopsy. Diagnostic thoracoscopy also has a higher sensitivity than pleural fluid cytology and needle biopsy.Case: We report a rare case of pseudomesotheliomatous carcinoma of the lung in a 50-year-old man with asbestos exposure. The patient had complained of dyspnea and chest roentgenogram showed left pleural effusion. Computed tomography (CT) of the chest revealed diffuse irregular left pleural thickening and without a clear initial primary lesion found in both of lung parenchyma, which mimicked pleural mesothelioma. Pleural tissue sampling was performed to obtain definitive diagnosis by video-assisted thoracoscopic surgery. At the operation, the tumor was found to have spread along the pleural surface and primary lesion was not detected in the right lung parenchyma. Immunohistochemically, the tumor was positive for Thyroid Transcription Factor- 1 (TTF-1), but negative for calretinin, P63, and Neuron Specific Enolase (NSE). Final diagnosis was adenocarcinoma of the lung and patient had good clinical response to Gefitinib.Conclusion: Based on the results of clinical studies (images and clinical observations), although pseudomesotheliomatous in patient with asbestos exposure is difficult to distinguish from pleural mesothelioma, we have a case of pseudomesotheliomatous lung diagnosed by a thoracoscopic pleura biopsy. For such cases, thoracoscopic pleural biopsy should be performed at an early stage.

DO DOCTORS GET SICK? A CASE OF PSEUDOMESOTHELIOMATOUS CARCINOMA IN A 47-YEAR-OLD MALE NONSMOKER DOCTOR

SESSION TITLE: Global Case Report Posters SESSION TYPE: Global Case Reports PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Pseudomesotheliomatous carcinoma is a rare type of lung adenocarcinoma (AD) that is characterized by growth in the pleural tissue of the chest cavity with clinical, radiological and even histological features similar to malignant mesothelioma. CASE PRESENTATION: A 47yo, never smoker, male doctor presented to our hospital with a 4-month history of left sided pleural pain. The past 15 years he lives and works in UK. On Christmas holidays, he visited his family and decided to undergo a plain CXR to see what this pleural pain was. CXR revealed a left pleural effusion. Thorax CT-scan demonstrated pleural fluid accumulation, pleural thickening areas and pleural nodules in the left hemithorax, as well as enlarged left hilar lymph nodes. A thoracentesis revealed an exudative. Analysis of two fluid samples reported benign characteristics and inflammation. A CT -guided FNB then was performed and a thoracic tube was placed to drain the hemithorax. A cytologic diagnosis of malignant cells was established based on new sambles of pleural fluid, possibly AD and IHC studies showed BerEP4(+), TTF1(+), CD56(-). Based on the results of the FNB, a histopathological diagnosis of pulmonary AD was made. Bronchoscopy and brain CT-scan were negative. The PET-CT scan demonstrated 18-FDG uptake by the pleural fluid, multiple nodules along the left pleura with possible infiltration of the diaphragm, peritoneal nodules and micronodules, nodular findings in the minor pelvis as well as by the left lobe of the thyroid gland. The CT-guided FNA of the thyroid gland was negative for malignancy. A new CT-guided FNB of the left pleura was performed and its histopathological analysis showed a well/moderately differentiated AD of the lung. Further IHC analysis revealed, TTF-1(+), CK7(+), CD15(+), EMA(+), BerEP4(+), Napsin-A(+), Calretinin(-), Thyroglobulin(-), Calcitonin(-), PAX-8(-), Chromogranin(-) and the fraction of Ki-67-positive tumor cells was 25%. Based on the clinical and laboratory findings the diagnosis of pseudomesotheliomatous type AD of the lung was made. To search for therapeutic strategies, additional gene detection was performed on the tissue sample, which showed no EGFR gene mutation (EGFRwt) but ALK rearrangement. The patient remains in excellent condition at the time of writing, under targeted therapy with alectinib. DISCUSSION: Pseudomesotheliomatous carcinomas most often are primary lung tumors but they can also be metastases from other sites. Adenocarcinoma of the lung is the most frequent type of malignancy that pseudomesotheliomatous carcinomas derive from as it also happened with our case. CONCLUSIONS: The treatment method for pseudomesotheliomatous tumors depends on the type and the origin of the given tumors with no specific guidelines published up to now and a poor prognosis is reported in most reviews in the literature. Our pt was ALK positive and it remains to see his clinical course with alectinib. Reference #1: Pseudomesotheliomatous’ carcinomas of the pleura: a 10-year analysis of cases from the Environmental Lung Disease Research Group, Cardiff R L Attanoos, A R Gibbs https://doi.org/10.1046/j.1365-2559.2003.01674.x Reference #2: Pseudomesotheliomatous carcinoma involving pleura and peritoneum: A clinicopathologic and immunohistochemical study of three cases. Shah IA1, Salvatore JR, Kummet T, Gani OS, Wheeler LA. Ann Diagn Pathol. 1999 Jun;3(3):148-59. Reference #3: Pseudomesotheliomatous lung carcinoma: a pathological assessment of selected cases including the work history and presence of biomarkers suggesting it is a cancer caused by asbestos. Samuel P. Hammar and Ronald F. Dodson. http://www.hoajonline.com/pathology/2052-7896/3/6 DISCLOSURES: No relevant relationships by Athanasios Andrianopoulos, source=Web Response No relevant relationships by Athanasia Athanasopoulou, source=Web Response No relevant relationships by Aikaterini Kavvada, source=Web Response No relevant relationships by Ilias Lyroudis, source=Web Response No relevant relationships by Asimina Nikolakopoulou, source=Web Response no disclosure on file for Georgios Noutsos; No relevant relationships by Emily Tsaroucha, source=Web Response No relevant relationships by Albanis Zannis, source=Web Response

A Case of Pseudomesotheliomatous Carcinoma of the Lung Definitively Diagnosed Based on the Results of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

A Case of Pseudomesotheliomatous Carcinoma of the Lung Definitively Diagnosed Based on the Results of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

局所麻酔下胸腔鏡を用いて診断しえた偽中皮腫性肺癌の1例

局所麻酔下胸腔鏡を用いて診断しえた偽中皮腫性肺癌の1例

A Case of Diffuse Pleural Invasion of Pseudomesotheliomatous Carcinoma with EGFR Mutation Diagnosed by Thoracoscopic Biopsy

A Case of Diffuse Pleural Invasion of Pseudomesotheliomatous Carcinoma with EGFR Mutation Diagnosed by Thoracoscopic Biopsy

Pseudomesotheliomatous lung carcinoma: a pathological assessment of selected cases including the work history and presence of biomarkers suggesting it is a cancer caused by asbestos

Abstract Background: We report a series of 196 cases of pseudomesotheliomatous neoplasms identified in one of our laboratories between 1983 and 2015. We also performed an extensive review of the literature. Most

Pseudomesotheliomatous carcinoma due to pleural metastasis from renal pelvic cancer.

A 78-year-old man was referred to our department with a one-week history of dyspnea and coughing. A chest X-ray showed massive left pleural effusion. Computed tomography revealed diffuse irregular thickening of the left pleura similar to malignant mesothelioma and multiple nodules in both lungs. The patient died of respiratory failure nine days after hospitalization. An autopsy revealed metastasis to the pleura and lungs from urothelial carcinoma of the left kidney.

Fatal Hemothorax Caused by Pseudomesotheliomatous Carcinoma of the Lung

We present a case of a poorly differentiated pseudomesotheliomatous carcinoma originating in the lung, which was manifested with the distinctly rare complication of massive true hemothorax and persistent blood loss that proved rapidly fatal in spite of surgery. Pseudomesotheliomatous carcinoma of the lung and neoplasia-associated hemothorax are reviewed and discussed.

631 Mislocalization of the apoptosome protein Apaf-1 is a strong marker of drug resistance in B cell lymphomas

We report 4 cases of pseudomesotheliomatous carcinoma of the lung, which has clinical and microscopic features similar to malignant mesothelioma, but with ultrastructural, immunohistochemical, and molecular characteristics suggestive of a histogenesis from type II pneumocytes. Neoplasm grows as a diffuse or solid pattern of large polygonal cells with sharply defined borders. Hale's colloidal iron is positive in the cytoplasm of small groups of cells and, focally, in some intercellular spaces. Ultrastructure showed short microvilli in the surface. Immunohistochemically, tumor cells were positive for thyroid transcription factor–1, podoplanin, mesothelin, pan-cytokeratin, CK-7, CK-19, Ber-EP4, epithelial membrane antigen, apoprotein surfactant A, epidermal growth factor receptor, Leu-M1, carcinoembryonic antigen, E-cadherin, and CD-44 and negative for mesothelioma markers thrombomodulin and calretinin. In some areas, there were small cysts which contained a concentric fibrilar basophilic material apoprotein surfactant A positive. Chromosomal imbalances with comparative genomic hybridization technique were identified with a median of 15 abnormalities per case (range, 1-26): 51 gains, 6 losses, and 1 high-level amplification. The most frequent aberrations among the cases were gains on chromosomes regions 1q, 3q, 5p, 8q, 16p, and 18q and losses in 17p11-13 and 17q 22-q25. High-level amplifications were detected on 7p13-p21. In all cases, there was a characteristic association between the gains on 16p and those on 18q. The 4 cases resulted in death in less than 14 months, in spite of complete surgery and chemotherapy in 2 cases. Our aim is to complement the current understanding of this pseudomesotheliomatous “pneumocytic” carcinoma and alert pathologists to this rare entity to avoid misdiagnosis.

289 3D culture systems for cancer drug evaluation

We report 4 cases of pseudomesotheliomatous carcinoma of the lung, which has clinical and microscopic features similar to malignant mesothelioma, but with ultrastructural, immunohistochemical, and molecular characteristics suggestive of a histogenesis from type II pneumocytes. Neoplasm grows as a diffuse or solid pattern of large polygonal cells with sharply defined borders. Hale's colloidal iron is positive in the cytoplasm of small groups of cells and, focally, in some intercellular spaces. Ultrastructure showed short microvilli in the surface. Immunohistochemically, tumor cells were positive for thyroid transcription factor–1, podoplanin, mesothelin, pan-cytokeratin, CK-7, CK-19, Ber-EP4, epithelial membrane antigen, apoprotein surfactant A, epidermal growth factor receptor, Leu-M1, carcinoembryonic antigen, E-cadherin, and CD-44 and negative for mesothelioma markers thrombomodulin and calretinin. In some areas, there were small cysts which contained a concentric fibrilar basophilic material apoprotein surfactant A positive. Chromosomal imbalances with comparative genomic hybridization technique were identified with a median of 15 abnormalities per case (range, 1-26): 51 gains, 6 losses, and 1 high-level amplification. The most frequent aberrations among the cases were gains on chromosomes regions 1q, 3q, 5p, 8q, 16p, and 18q and losses in 17p11-13 and 17q 22-q25. High-level amplifications were detected on 7p13-p21. In all cases, there was a characteristic association between the gains on 16p and those on 18q. The 4 cases resulted in death in less than 14 months, in spite of complete surgery and chemotherapy in 2 cases. Our aim is to complement the current understanding of this pseudomesotheliomatous “pneumocytic” carcinoma and alert pathologists to this rare entity to avoid misdiagnosis.

P.303 A review of FNA/core biopsies in head and neck lumps

We report 4 cases of pseudomesotheliomatous carcinoma of the lung, which has clinical and microscopic features similar to malignant mesothelioma, but with ultrastructural, immunohistochemical, and molecular characteristics suggestive of a histogenesis from type II pneumocytes. Neoplasm grows as a diffuse or solid pattern of large polygonal cells with sharply defined borders. Hale's colloidal iron is positive in the cytoplasm of small groups of cells and, focally, in some intercellular spaces. Ultrastructure showed short microvilli in the surface. Immunohistochemically, tumor cells were positive for thyroid transcription factor–1, podoplanin, mesothelin, pan-cytokeratin, CK-7, CK-19, Ber-EP4, epithelial membrane antigen, apoprotein surfactant A, epidermal growth factor receptor, Leu-M1, carcinoembryonic antigen, E-cadherin, and CD-44 and negative for mesothelioma markers thrombomodulin and calretinin. In some areas, there were small cysts which contained a concentric fibrilar basophilic material apoprotein surfactant A positive. Chromosomal imbalances with comparative genomic hybridization technique were identified with a median of 15 abnormalities per case (range, 1-26): 51 gains, 6 losses, and 1 high-level amplification. The most frequent aberrations among the cases were gains on chromosomes regions 1q, 3q, 5p, 8q, 16p, and 18q and losses in 17p11-13 and 17q 22-q25. High-level amplifications were detected on 7p13-p21. In all cases, there was a characteristic association between the gains on 16p and those on 18q. The 4 cases resulted in death in less than 14 months, in spite of complete surgery and chemotherapy in 2 cases. Our aim is to complement the current understanding of this pseudomesotheliomatous “pneumocytic” carcinoma and alert pathologists to this rare entity to avoid misdiagnosis.

Pseudomesotheliomatous carcinoma of the lung with a distinct morphology, immunohistochemistry, and comparative genomic hybridization profile

We report 4 cases of pseudomesotheliomatous carcinoma of the lung, which has clinical and microscopic features similar to malignant mesothelioma, but with ultrastructural, immunohistochemical, and molecular characteristics suggestive of a histogenesis from type II pneumocytes. Neoplasm grows as a diffuse or solid pattern of large polygonal cells with sharply defined borders. Hale's colloidal iron is positive in the cytoplasm of small groups of cells and, focally, in some intercellular spaces. Ultrastructure showed short microvilli in the surface. Immunohistochemically, tumor cells were positive for thyroid transcription factor-1, podoplanin, mesothelin, pan-cytokeratin, CK-7, CK-19, Ber-EP4, epithelial membrane antigen, apoprotein surfactant A, epidermal growth factor receptor, Leu-M1, carcinoembryonic antigen, E-cadherin, and CD-44 and negative for mesothelioma markers thrombomodulin and calretinin. In some areas, there were small cysts which contained a concentric fibrilar basophilic material apoprotein surfactant A positive. Chromosomal imbalances with comparative genomic hybridization technique were identified with a median of 15 abnormalities per case (range, 1-26): 51 gains, 6 losses, and 1 high-level amplification. The most frequent aberrations among the cases were gains on chromosomes regions 1q, 3q, 5p, 8q, 16p, and 18q and losses in 17p11-13 and 17q 22-q25. High-level amplifications were detected on 7p13-p21. In all cases, there was a characteristic association between the gains on 16p and those on 18q. The 4 cases resulted in death in less than 14 months, in spite of complete surgery and chemotherapy in 2 cases. Our aim is to complement the current understanding of this pseudomesotheliomatous "pneumocytic" carcinoma and alert pathologists to this rare entity to avoid misdiagnosis.

Clinicopathological analysis of lung cancer resembling malignant pleural mesothelioma

The aim of this study was to evaluate the clinicopathological features of lung cancer resembling malignant pleural mesothelioma. The seven patients studied had tumours showing an extensive pleural growth pattern, and were chosen from 1516 lung cancer patients diagnosed at two affiliated hospitals over a 17-year period. Histologically, five of these lung cancers were adenocarcinomas, one was a small cell carcinoma, and one a large cell carcinoma. Tumour markers such as carcinoembryonic antigen (CEA) were elevated in six patients at admission. However, a clinical diagnosis was difficult and these cancers could only be distinguished from malignant pleural mesothelioma by thoracentesis in two cases, pleural biopsy in two, thoracotomy in two, and in case 7 at autopsy. Treatment consisted of chemotherapy or radiation therapy in four patients, but with little clinical effect. The mean survival time was 6.7 months, which is much less than for true malignant pleural mesothelioma. Lung cancer resembling malignant pleural mesothelioma is most frequently observed in patients with adenocarcinoma, which is suspected to occur peripherally. To distinguish pseudomesotheliomatous carcinoma from malignant pleural mesothelioma in patients with diffuse pleural thickening and effusion, requires adequate tissue sampling by thoracotomy or video-assisted thoracoscopic surgery and a panel of immunohistochemical stains.

The utility and limitation of thyroid transcription factor-1 protein in primary and metastatic pulmonary neoplasms

Thyroid transcription factor-1 (TTF-1) is a tissue-specific transcription factor expressed in the thyroid and lung. The clinical utility and limitation of TTF-1 in primary or metastatic carcinomas of the lung have not been previously studied in detail. We examined TTF-1 expression in 510 primary lung and 107 metastatic neoplasms. TTF-1 was detectable in 4/99 (4%) squamous cell carcinomas, 169/176 (96%) solitary adenocarcinomas, 34/34 (100%) multifocal adenocarcinomas, 1/1 (100%) signet ring cell carcinoma, 16/20 (80%) mucinous adenocarcinomas, 23/23 (100%) nonmucinous bronchioloalveolar carcinomas, 19/36 (53%) small cell carcinomas, and 39/44 (89%) sclerosing hemangioma. TTF-1 was absent in all eight carcinoids, three atypical carcinoids, 23 pleomorphic carcinomas, 25 lymphoepithelioma-like carcinomas, the sarcomatous component of one pseudomesotheliomatous carcinoma, and one mesothelioma. In four combined small cell carcinomas and 12 adenosquamous carcinomas, TTF-1 expression was only demonstrated in the adenocarcinoma component. There were 78 TTF-1 non-immunoreactive metastatic cases from 22 livers, 20 colorectums, 10 breasts, six nasopharynx, four larynx, four ovaries, three salivary glands, three esophagus, two adrenal glands, two kidneys, one bile duct, and one endometrium. TTF-1 was also detected in all 10 cervical lymph nodes, seven brain, and 6/7 (86%) bony tissues of 24 patients with metastatic carcinomas of unknown primary site, but it was absent in 125 patients with metastatic carcinomas other than lung origin in cervical lymph nodes, brain, and bony tissues. These results indicate the clinical usefulness and limitation in certain primary and metastatic lung neoplasms.

Pseudomesotheliomatous carcinoma of the lung. An immunohistochemical and ultrastructural study of three cases

The authors report immunohistochemical and electron microscopic studies on three new cases of pseudomesotheliomatous carcinoma of the lung. Although the distinct clinical and histopathologic features of this peripheral lung cancer were described many years ago, its recognition as a distinct variety of lung carcinoma has not gained wide acceptance. Little is known of its incidence and only few cases have been reported until now. In the current study the authors demonstrate the epithelial nature of this tumor by its positive immunohistochemical reactions for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Leu-M1, B 72.3, and surfactant apoprotein. The ultrastructural features and staining of nuclear inclusions with surfactant apoprotein indicate differentiation into type II cells as found in other forms of peripheral lung adenocarcinoma. Despite these morphologic similarities, pseudomesotheliomatous carcinoma is characterized by extensive invasion of the pleura and rapidly fatal course. Because of this biologic behavior it deserves recognition as a distinct variant of peripheral lung carcinoma.