Role of Cytology in the Current Guidelines for Malignant Mesothelioma: Largest Study from India

Abstract

<b><i>Introduction:</i></b> Cytology provides crucial window for early diagnosis of malignant mesothelioma (MM) since it is often the first and easily available material for evaluation, resulting in early treatment. Still, its role is overlooked in the current treatment guidelines. The aim of this study is to determine the sensitivity of cytomorphology and role of subsequent ancillary techniques in diagnosing MM. <b><i>Methods:</i></b> This is a 5-year retrospective analysis of MM in the tertiary oncology center to determine sensitivity of cytomorphology and subsequent role of immunohistochemistry (IHC) in final diagnosis of MM according to the guidelines for cytopathologic diagnosis of epithelioid and mixed-type malignant mesothelioma (GCDMM) laid by International Mesothelioma Interest Group. Cytomorphology and immunocytochemistry from effusions and fine needle aspirations were analyzed. <b><i>Results:</i></b> Sixty-two of 128 cases of MM had cytology and cytomorphological criteria described in GCDMM were fulfilled in 61.3% cases. Architectural atypia was useful in identifying cases with low cytological atypia. Overall sensitivity of cytomorphology was 73.01%. Sensitivity of effusion cytology was 77.8%. Subsequent IHC on cell blocks revealed the sensitivity as 100% for mesothelin, calretinin, and cytokeratin 5/6; 87.5% for thrombomodulin; and 50% for WT1, while CEA and TTF1 showed 100% specificity. Treatment was given based on final diagnosis of MM given after IHC on cytology material in only 25.8% cases. However, it was possible in additional 35.5% cases. Mean survival was 10 months when diagnosed by cytology, compared to 7 months by histology. <b><i>Conclusions:</i></b> Rather than ignoring the role of cytology in the diagnosis and treatment guidelines for MM, it is important to understand its strengths and limitations. Standardized guidelines in future can play an important role in more streamlined communication between cytopathologist and clinician.

Evaluation of DNA/RNA quality from cell block of malignant mesothelioma and lung adenocarcinoma

“…ICC has been shown to have superior staining results in cell blocks compared to conventional smears and LBC specimens. 9,[13][14][15] In this study, we prepared cell blocks from cells pretreated with an LBC fixative solution and cell blocks from LBC residual specimens. Our preliminary experiments showed that the immunostaining of cells treated with LBC fixative was lower than that of cells fixed with 10% NBF.…”

“…Therefore, morphological approaches are limited, and ICC, FISH, and nucleic acid sequence analyses using DNA and RNA extraction are useful. ICC has been shown to have superior staining results in cell blocks compared to conventional smears and LBC specimens 9,13–15 . In this study, we prepared cell blocks from cells pretreated with an LBC fixative solution and cell blocks from LBC residual specimens.…”

The Status of Indian Cancer Record Keeping and Study of Mesothelioma Cases to Ascertain Asbestos Exposure in India

“…This reporting may be due to the smaller numbers, as compared to other cancers, but this rarity cannot be considered as absence of mesothelioma in India. On the other hand, in another study, which is stated by its authors to be the ‘largest study from India’ on malignant mesothelioma, the proven cases from 2015 to 2019 in the archives of the Department of Onco-pathology at Gujarat Cancer Research Institute were 128 10 .…”