[Immunohistochemistry in the differential diagnosis of mesothelioma and adenocarcinoma. Evaluation of 5 new antibodies and 6 traditional antibodies]. / L'immunohistochimie dans le diagnostic différentiel entre mésothéliome et adénocarcinome. Evaluation de 5 nouveaux anticorps et réévaluation de 6 anticorps traditionnels.

The aim of this study was to evaluate three recently marketed putative mesothelioma-binding antibodies, calretinin, HBME-1 and thrombomodulin, and two putative adenocarcinoma-binding antibodies, AUA1 and MOC31, on paraffin sections from 28 mesotheliomas and 30 adenocarcinomas. Moreover, the expression of ACE, BerEP4, CA125, CA19.9, LeuM1 and vimentin was assessed. Calretinin, HBME-1 and thrombomodulin, which showed a 100%, 89% and 43% sensitivity, and a 50%, 70% and 87% specificity for mesothelioma respectively, were less efficient than vimentin (100% specificity and 67% sensitivity) for the positive identification of mesothelioma. AUA1, BerEP4 and MOC31 were 100% sensitive to adenocarcinoma, with BerEP4 and MOC31 having the highest specificity (86% each). The immunophenotype "vimentin-positive, ACE-negative, CA19.9-negative" yielded 100% sensitivity and 97% specificity for diagnosis of mesothelioma. We advocate the use of the four-marker panel of ACE, CA19.9, MOC31 (or BerEP4) and vimentin for differentiating mesothelioma from adenocarcinoma.

[Uninodular bronchiolo-alveolar cancer. Apropos of 5 cases with a prolonged course]. / Les cancers bronchiolo-alvéolaires uninodulaires. A propos de 5 cas d'évolution prolongée.

Five cases of uninodular bronchioloalveolar cell (BAC) carcinoma are reported. These 5 cases were characterized by the protracted course of the disease: 14.5 and 11.5 years respectively in the 2 patients who died; 7.5, 12 and 12.5 years respectively in the 3 patients who are still alive. Prior to being diagnosed at excision, the tumours had been followed up for an unusual 2 to 10 years period, with phases of radiological stability and phases of very slow growth. This very slow course is exceptional in lung cancer. It differs not only from the course of diffuse BAC carcinoma, but also from the habitual course of uninodular BAC carcinoma and from that of peripheral adenocarcinoma. Similar cases could be found in the literature, and a comparative study has been conducted between these slow-course carcinomas and normal-course carcinomas. Whatever their outcome, slow-course carcinomas are asymptomatic tumours which present at radiography of the chest as a peripheral round or oval opacity devoid of pathognomonic features. The post-operative prognosis of slow-course tumours seems to be more favourable than that of the other lung cancers. At histology, carcinomas with a protracted course usually show a pattern similar to that of lesions called by some authors "benign adenomatosis"; however, some of these tumours exhibit fairly distinct signs of malignancy, and electron microscopic images also are far from being uniform.