Aliya N Husain1, M Kamran Mirza2, Allen Gibbs3, Kenzo Hiroshima4, Yiqing Chi2, Redouane Boumendjel2, Nolwenn Stang5, Thomas Krausz2, Francoise Galateau-Salle5. 1. The University of Chicago Medical Center, 5841 South Maryland Avenue, Chicago, IL 60637, USA. Electronic address: Aliya.husain@uchospitals.edu. 2. The University of Chicago Medical Center, 5841 South Maryland Avenue, Chicago, IL 60637, USA. 3. Llandough Hospital, Penlan Road, Llandough, Penarth, South Glamorgan, UK. 4. Tokyo Women's Medical University Yachiyo Medical Center, 477-96 Owada-Shinden, Yachiyo 276-8524, Japan. 5. Laboratoire d'Anatomie Pathalogique, Caen, France.
Abstract
OBJECTIVE: Mesothelial hyperplasia (MH) and fibrosing pleuritis (FP) can be difficult to distinguish from epithelioid (MM-E) and sarcomatoid (MM-S) malignant pleural mesotheliomas. GLUT-1 has shown variable results regarding its sensitivity and specificity when used to evaluate mesothelial proliferations. We evaluated the utility of GLUT-1 immunostaining in differentiating MH and FP from MM-E and MM-S. MATERIALS AND METHODS: In this retrospective study, diagnostically well-characterized cases (MH=31, FP=29, MM-E=41, MM-S=29) were collected and manually stained for GLUT-1. All slides were visually scored by 2 pathologists; using the following system: 0%, 1+ 1-25%, 2+ 26-50% and 3+ >51% cells staining. RESULTS: All benign cases (n=60) were negative for GLUT-1 while 45 of 78 (58%) MM [21 of 41 (50%) MM-E, 21 of 29 (72%) MM-S and 3 of 3 biphasic mesothelioma (100%)] had 1+ to 3+ staining. Of the MM-E, 10 had 1+, and 11 had 2+ staining; of the MM-S 3 had 1+, 15 had 2+ and 3 had 3+ staining. Both sarcomatoid and epithelioid components of the 3 biphasic mesotheliomas revealed 1+ staining. All 5 desmoplastic MM were negative. CONCLUSIONS: Positive staining with GLUT-1 is helpful since it is present in half of MM-E and three-quarter of MM-S. Although all reactive mesothelial lesions were negative, the absence of immunoreactivity does not exclude the diagnosis of MM. As with all IHC stains used for diagnostic purposes, GLUT-1 has to be a part of a panel, and the results interpreted in the context of clinical, radiological and histological findings.
OBJECTIVE: Mesothelial hyperplasia (MH) and fibrosing pleuritis (FP) can be difficult to distinguish from epithelioid (MM-E) and sarcomatoid (MM-S) malignant pleural mesotheliomas. GLUT-1 has shown variable results regarding its sensitivity and specificity when used to evaluate mesothelial proliferations. We evaluated the utility of GLUT-1 immunostaining in differentiating MH and FP from MM-E and MM-S. MATERIALS AND METHODS: In this retrospective study, diagnostically well-characterized cases (MH=31, FP=29, MM-E=41, MM-S=29) were collected and manually stained for GLUT-1. All slides were visually scored by 2 pathologists; using the following system: 0%, 1+ 1-25%, 2+ 26-50% and 3+ >51% cells staining. RESULTS: All benign cases (n=60) were negative for GLUT-1 while 45 of 78 (58%) MM [21 of 41 (50%) MM-E, 21 of 29 (72%) MM-S and 3 of 3 biphasic mesothelioma (100%)] had 1+ to 3+ staining. Of the MM-E, 10 had 1+, and 11 had 2+ staining; of the MM-S 3 had 1+, 15 had 2+ and 3 had 3+ staining. Both sarcomatoid and epithelioid components of the 3 biphasic mesotheliomas revealed 1+ staining. All 5 desmoplastic MM were negative. CONCLUSIONS: Positive staining with GLUT-1 is helpful since it is present in half of MM-E and three-quarter of MM-S. Although all reactive mesothelial lesions were negative, the absence of immunoreactivity does not exclude the diagnosis of MM. As with all IHC stains used for diagnostic purposes, GLUT-1 has to be a part of a panel, and the results interpreted in the context of clinical, radiological and histological findings.