Malignant mesothelioma eight years after a diagnosis of atypical mesothelial hyperplasia

Clinicopathological features of radiological early malignant pleural mesothelioma with no apparent tumor or pleural thickening

BACKGROUND

We occasionally encounter malignant pleural mesothelioma (MPM) of no apparent tumor or pleural thickening that is radiological early MPM. This study aimed to examine the clinicopathological outcomes of radiological early MPM.

METHODS

Patients with MPM treated with neoadjuvant chemotherapy and planned surgery at the time of diagnosis between July 2004 and December 2019 were retrospectively examined. Pretreatment maximal pleural thickness of all patients was measured on chest computed tomography. We extracted and investigated the patients who exhibited a lack of pleural thickening or visible tumor, which was defined as radiological early MPM. Survival was analyzed by the Kaplan-Meier method.

RESULTS

Of 296treated patients, 16 (5.4%) exhibited radiological early MPM. Fourteen (87.5%) of these patients underwent pleurectomy/decortication and 2 (12.5%) underwent extrapleural pneumonectomy. Pathological stage T1 disease was diagnosed in 14 (87.5%) patients; 2 (12.5%) exhibited pulmonary parenchymal invasion (pathological stage T2). Lymphatic invasion was detected in only 1 patient. Lymph node metastases and vascular invasion were not detected. Median follow-up was 42 months. Median progression-free survival and median overall survival were 40.7 and 56.1 months, respectively. The 3-year progression-free survival and overall survival rates were 84.8% and 83.6%, respectively.

CONCLUSIONS

Radiological early MPM occurs in approximately 1 of every 20 patients treated with neoadjuvant chemotherapy and surgery planned at the time of diagnosis in an experienced center. Radiological early MPM was associated with early pathological stage and long-term survival.

p53 Expression in a Malignant Mesothelioma Patient during Seven-Year Follow-up

Malignant mesothelioma (MM) is the aggressive tumor of serosal surfaces. There are crude pathogenetic results regarding the biology of MM. Coordinated upregulations of p53 gene expression are shown in malignancies. We believed that there are changes in the p53 expression with transformation from reactive hyperplasia to MM. A 65-year-old male was admitted the hospital because of left pleuritic chest pains in 2004. Chest computed tomography (CT) results showed left pleural effusions with loculation and pleural thickening. Pathologic findings revealed reactive mesothelial hyperplasia. In 2008, the patient again felt left pleuritic chest pains. Chest CT showed progressive thickening of the left pleura. Pathologic diagnosis was atypical mesothelial hyperplasia. In 2011, chest CT showed progressive thickening of his left pleura. He was diagnosed with well-differentiated papillary mesothelioma. Serial change was analyzed by immunohistochemical staining for p53 of pleural tissues. There were no remarkable changes in p53 expressions during the transformation to MM.

A rare cause of heart failure with preserved ejection fraction: primary pericardial mesothelioma masquerading as pericardial constriction

We present a case of a 30-year-old woman with a history of HIV and hepatitis C who sought medical attention because of severe oedema of the lower limbs and abdomen. CT of the chest showed a thickened pericardium, and cardiac catheterisation demonstrated constrictive physiology. She underwent pericardiectomy, but the procedure was unsuccessful because the pericardium was densely adherent to the myocardium. After consultation with several pathologists, she was diagnosed with primary pericardial mesothelioma (PPM), an exceedingly rare cardiac tumour with a fatal prognosis. She died within 3 months of presentation. The details of the case as well as pertinent literature are reviewed.

CD147 immunohistochemistry discriminates between reactive mesothelial cells and malignant mesothelioma

Malignant mesothelioma (MM) is a rare form of cancer. Its histopathological diagnosis is very difficult, as it exhibits a number of different appearances that can be misinterpreted as metastatic invasion or atypical hyperplasia. Thus, there is an urgent need to identify adequate markers to distinguish between benign and malignant cells, allowing the implementation of appropriate therapies and, possibly, specific directed therapies. MM, like other tumors, show an increase in glucose uptake, due to high rates of glycolysis, inducing an intracellular overload of acids. In this context, monocarboxylate transporters (MCTs) emerge as important players, by mediating the transmembranar co-transport of lactate with a proton, thereby, regulating pH and allowing continuous glycolysis. Importantly, proper MCT expression and activity depend on its co-expression with a chaperone, CD147, which is associated with poor prognosis in cancer. Twenty-two samples including reactive mesothelial cells, MM, and atypical mesothelial hyperplasias were evaluated for immunoexpression of MCT1, MCT4, and CD147. Expression of these proteins was compared with GLUT1 as a new promising marker for MM. Although MCT isoforms were not differentially expressed in the two types of cytological specimens, CD147, as GLUT1, was almost exclusively expressed in MM. Both MCT1 and MCT4 are not able to discriminate between mesothelial reactive cells and mesothelial malignant cells, while CD147 was able to distinguish these two proliferations. If confirmed, besides being a good marker for identification of MM, CD147 may also be a target for therapeutical strategies in this rare type of tumor.

Well-differentiated papillary mesothelioma occurring in the tunica vaginalis of the testis with contralateral atypical mesothelial hyperplasia

Well-differentiated papillary mesothelioma (WDPM) occurs rarely in the paratesticular region, with only a handful of published case reports. Often presenting with recurrent hydrocele, WDPM is a multifocal mesothelial proliferation with a predominantly indolent clinical course. Accordingly, pathologic distinction of this lesion from true malignant mesothelioma is crucial, although it may be difficult because of the variability of associated histologic features. In addition, rare cases of WDPM have progressed to malignant mesothelioma, leading to its classification as a tumor of low malignant potential. Here, we report a case of multifocal WDPM occurring in the tunica vaginalis and tunica albuginea, with contralateral atypical mesothelial hyperplasia, a potentially premalignant lesion.

Miscellaneous conditions of the appendix

A variety of miscellaneous conditions affect the appendix, both as incidental findings and as causes of clinical signs and symptoms that often mimic appendicitis. Congenital abnormalities of the appendix are rare; the two most commonly reported are congenital absence and appendiceal duplication. Diverticular disease may be an incidental finding, but when inflamed, can be clinically confused with appendicitis. Endometriosis of the appendix, which usually occurs in the setting of generalized gastrointestinal endometriosis, often presents as acute appendicitis, but may present as intussusception, lower intestinal bleeding, and, particularly during pregnancy, perforation. Peritoneal endosalpingiosis often involves the appendiceal serosa and occasionally the wall but has no clinical manifestations in contrast to endometriosis. Vasculitis may be either isolated to the appendix or part of a systemic vasculitis, most often polyarteritis nodosa. Neural proliferations of the appendix include lesions associated with von Recklinghausen's disease, as well as mucosal and axial neuromas that are theorized to progress to fibrous obliteration of the appendix. Mesenchymal tumors of the appendix are most often of smooth muscle type, usually leiomyoma but rarely leiomyosarcoma; nonmyogenic neoplasms such as gastrointestinal stromal tumor, granular cell tumor, Kaposi's sarcoma, and miscellaneous other curiosities occur rarely. Lymphoma affects the appendix exceptionally; in children, Burkitt lymphoma is most common whereas in adults, large cell lymphomas and low grade B-cell lymphomas predominate. Secondary involvement of the appendix by leukemia has been reported. Secondary involvement of the appendix by carcinomas of the female genital tract, particularly ovary, and diverse other sites are in aggregate common but only rarely a clinical or pathological difficulty. Occasionally, however, appendiceal neoplasia that is secondary from another site may dominate the clinical picture and lead to potential pathologic misdiagnosis as primary appendiceal disease.

Genetics of malignant pleural mesothelioma: molecular markers and biologic targets

MPM is a poorly understood lethal malignancy. Although the pathobiology of MPM is not completely elucidated, new genomic technology is likely to help shed light on the mechanisms of carcinogenesis through genome-wide screening of tumor-specific gene expression. Related efforts to identify the molecular markers of mesothelioma are pursued with the aim of refining current diagnostic capabilities, predicting prognosis, and designing appropriate trimodality programs. These new genomic tools also will assist efforts to tailor current adjuvant and neoadjuvant therapies, optimizing their effect and furthering research that may lead to new therapeutic options.

The usefulness of a panel of immunostains in the diagnosis and differentiation of metastatic malignancies in pericardial effusions

Pericardial effusions are not uncommon in patients with an advanced malignancy Rarely malignancies may present initially with a pericardial effusion. Cytological examination of pericardial fluid may be valuable in differentiation of these cases. However, a metastatic tumour in serous effusion may not always show the functional differentiation of the primary tumour. In such a situation, although a wide range of special studies have been suggested for the diagnosis of malignancy we have found the use of a panel of a few common immunostains to be useful in confirming or suggesting the site of a primary tumour. The material for this study consisted of 76 pericardial fluids obtained between January 1991 and October 1998 from 46 males (mean age 59 years) and 30 females (mean age 52 years). Metastatic malignancy was diagnosed in 22 of the 76 patients and in 7/22 cases pericardial effusions were the initial presentation. The subsequent follow-up in the seven cases revealed adenocarcinoma of lung (n = 2), small cell anaplastic carcinoma of lung (n = 1), squamous cell carcinoma lung (n = 1), melanoma leg (n = 1), non-Hodgkin's lymphoma retroperitoneal lymph nodes (n = 1) and carcinoma of the breast (n = 1). Of the remaining 15 cases with a known history of malignancy, eight had cancers (three adeno; two small cell; one poorly differentiated, and two squamous cell types) of the lung; breast (n = 3); colon (n = 1); melanoma (n = 2) and non Hodgkin's lymphoma (n = 1). Immunostains which were useful in the diagnosis were EMA, CEA, cytokeratin, B72.3, HMB45, vimentin, S100, LCA, L26 and kappa and lambda light chains.