SESSION TITLE: Cancer Student/Resident Case Report Posters I
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare disease with a remarkable variety of morphological features, limited therapeutic options and a poor prognosis. A cornerstone of the pathological diagnosis is the demonstration of tissue invasion. Therefore, the general acceptance of a cytological diagnosis of malignant mesothelioma is low. However, even independently from the amount of available tissue the diagnosis can be a challenge.
CASE PRESENTATION: A 70-year-old female presented with spontaneous pneumothorax. Repeated video assisted thoracoscopy (VATS) with pleurectomy and talc pleurodesis was necessary. Eight months later pleural effusion occured on the same side and a seropneumothorax contralaterally. Several pleura specimens showed benign mesothelial proliferations. Cytology diagnosis of the effusion was malignant mesothelioma, and hyaluronic acid (HA) concentration was elevated (456 mg/l). The chest CT-scans revealed pleural thickening on both sides with suspicion for malignant mesothelioma. Again, histological analysis was difficult and did not suggest malignancy. In contrast, cytology of the left side effusion confirmed malignant mesothelioma and chemotherapy was initiated. The German Mesothelioma Register later confirmed the diagnosis after re-evaluation of the histology specimens. The patient died two weeks after the confirmation of the histological diagnosis and the initiation of chemotherapy.
DISCUSSION: The differential diagnosis of mesothelioma was raised early in the presented case, but in spite of multiple pleural resections on both sides the histological changes were classified as benign proliferations. The absence of radiological signs or a history of asbestos exposition added to the diagnostic dilemma. There was tissue available, but it was very difficult to distinguish benign changes due to prior manipulations, talc instillation and inflammation from the required criteria of tissue invasion. While the sensitivity of cytological MPM diagnosis is fairly limited, the specifity is comparable to histological diagnosis.Therefore, consideration of cytologic results complemented by HA measurements could have led to a 6 months earlier diagnosis avoiding unnecessary invasive procedures. We suggest that in cases with characteristic clinical features, progressive disease and compromised clinical state a MPM diagnosis confirmed by cytology combined with results of HA analysis should be accepted.
CONCLUSIONS: Cytological MPM diagnosis should be sufficient in patients with characteristic clinical features, elevated HA concentration, progressive disease and limited functional status, when biopsy samples are inconclusive or not available.
Reference #1: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart, WHO Classification of Tumours, 2004
Reference #2: Welker et al. Cytological diagnosis of malignant mesothelioma-improvement by additional analysis of hyaluronic acid in pleural effusions. Virchows Arch. 2007 Apr;450(4):455-61.
DISCLOSURE: The following authors have nothing to disclose: Antony Kanappilly, Klaus Friedrich Rabe, David Felix Heigener, Florian Stellmacher, Lutz Welker
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