Le profil anatomoclinique du mésothéliome pleural malin : une étude rétrospective à propos de 30 cas

Abstract

The malignant pleural mesothelioma (MPM) is a rare tumour usually associated to asbestos exposure. The delay between the exposure and the occurrence of the cancer can reach 40years. This caused the pick of incidence described in many countries including Tunisia. The diagnosis is suspected based on clinical features but positive diagnosis is microscopic. Our aim was to describe the clinical and microscopic features of MPM through a single institution experience. We conducted a retrospective study about 30MPM diagnosed over a 20-year-period (1995-2015). We included only patients with complete records including clinical, radiologic and microscopic features. All the microscopic diagnoses were reviewed by 2pathologists. A mean of 12slides per case was reviewed. The diagnosis was based on the 2015WHO classification. The mean age of the patients was 61years, average 22to 80years. The sex ratio was 6,5. An asbetose exposition was reported in 21cases. The most frequent symptoms was chest pain reported in 25cases. Physical exam was normal in 9cases. It revealed pleural syndorm in most patients (60%). Imaging findings consisted mainly in diffuse pleural thickening in 17cases. Twelve tumours were classified as stage I, 3stage II, 14stage III et 1stage IV. Pleural biopsy was performed using needle in 18cases, through thoracoscopy in 16cases, thoracotomy in 3cases and allowed the diagnosis in respectively 7cases/18, 16cases/16and 3cases/3. A lymph node biopsy was performed through mediastinoscopy in one case and yelded the diagnosis. The diagnosis was performed on surgical specimen in 2patients: one bullectomy and one right upper lobectomy. The microscopic exam concluded to an EM in 17cases, sarcomatoid mesothelioma (SM) in 4cases and biphasic mesothelioma (BM) in 9cases. Pan-cytokeratin antibody was used in all cases in association with 2antibodies with positive diagnostic value and 2antibodies with negative diagnostic value. It was repeated in 15cases and the most used antibodies were the anti-calretinin and the TTF1. This was due to the lack of fixation in one case and in order to reach a quality criteria in the other cases. Surgical resection was possible in 2patients. 15patients were lost of view after a mean follow-up period of 3months. Thirteen patients died before or during the follow-up. This work was about a Tunisian experience in the diagnosis and management of MPM. The major limits faced were the incomplete databases, the small number of patients included. Microsocpic positive diagnosis necessitates a degree of expertise and every laboratory has to determine the most valuable antibodies through its experience in order to optimize the diagnosis and to reduce the delay of diagnosis.