Scoring system for differential diagnosis of malignant mesothelioma and reactive mesothelial cells on cytology specimens

Abstract

Cytology is the only useful tool in the detection of malignant mesothelioma (MM) at an early stage. No other methods, such as immunocytochemistry or electron microscopy, are available to distinguish MM from reactive mesothelial cells (RMC). Some objective analysis of cytology specimens is necessary. On the basis of our case review and cytological features described in previous articles, we developed a scoring system for malignant mesothelioma (SSMM) of effusion cytology to distinguish MM cells from RMC. Mesothelioma cells in effusions from 22 patients (20 pleural and 2 peritoneal mesotheliomas) were compared with RMC from 20 patients without obvious tumor cells and 50 effusions containing metastatic carcinoma cells. The SSMM is based on characteristic features of mesothelial and malignant cells. The total achievable score is 10 points: one point each is given for variety of cell size, cyanophilic cytoplasm with villosity/windows/bleb, sheet-like arrangement, mirror-ball-like cell clusters, nuclear atypia, and cannibalism, respectively. Further two points each are ascribed for acidophilic large nucleoli and multinucleated cells with more than eight nuclei. The total score for each of the 22 mesotheliomas was more than 5 points. On the other hand, all RMC and the 50 metastatic carcinoma cases scored less than 3 points, aside from two cases that were treated with OK432. No single characteristic feature was observed to be consistent within the 22 mesotheliomas analyzed. Ancillary use of immunocytochemistry, such as podoplanin (D2-40) and calretinin, supported the diagnostic accuracy of the SSMM. SSMM is useful for the differential diagnosis of MM.

Immunocytochemistry of CD146 is useful to discriminate between malignant pleural mesothelioma and reactive mesothelium

“…26 However, to achieve the differential diagnosis successfully, numerous cytomorphological parameters are required. A variety of markers, such as EMA, desmin, GLUT-1, and p53, have been reported to be useful in the discrimination of malignant mesothelioma and reactive mesothelium, but the results are not consistent.…”

Pathological and molecular biological approaches to early mesothelioma

“…However, it has been considered that MPM should not be diagnosed by pleural effusion cytology, since the reliable cytological criteria for the diagnosis of MPM has not been established so far and invasion cannot be assessed with specimens used in effusion fluid cytology [6,[10][11][12]. Recently, characteristic cells of MPM of epithelial type in pleural effusion have been collected and analyzed [13,14]. In addition, several molecular markers, which may assist diagnosis of early-stage MPM of epithelial type in pleural effusion cytology and histology, have been developed [15][16][17][18][19].…”

Binucleated HeLa cells are formed by cytokinesis failure in starvation and keep the potential of proliferation

“…In normal tissues, such as liver parenchyma, a relationship between binucleated cells and cell survival was reported (Morizur et al 2010). Many cytological studies have found elevated numbers of binucleated cells in various tumors (Bollmann et al 2005;Kimura et al 2009;Minimo et al 2002;Morin et al 2000;Stelow et al 2006;Stoll et al 2011). However, binucleated cells are observed in not only malignant tumors but also normal tissues (Mizoguchi and Ishikawa 1994;Morizur et al 2010).…”

“…Many cytological studies have reported that the numbers of binucleated cells were elevated in various tumors, including malignant mesothelioma, pancreatic endocrine tumor, cervical squamous lesion, angiosarcoma, and acute myeloid leukemia (Bollmann et al 2005;Kimura et al 2009;Minimo et al 2002;Morin et al 2000;Stelow et al 2006;Stoll et al 2011). However, binucleated cells are observed in not only malignant tumors but also normal tissues such as those of the heart, muscle cells, platelet progenitor-megakaryocytes, liver parenchyma, and bladder (Mizoguchi and Ishikawa 1994;Morizur et al 2010).…”