SESSION TITLE: Disorders of the Pleura Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Sarcomatoid mesothelioma ( SM) is the least common of the mesothelioma cell types and the most resistant to cancer therapies. Diagnosis is challenging because the cells can resemble other cancers. We present a case of 53 year old man who had entrapped lung which was initially misdiagnosed as Fibrinous pleurisy but subsequently developed metastatic lesions and was diagnosed with SM.
CASE PRESENTATION: A 53-year old man presents with recurrent right sided pleural effusion and collapse of the right lung. He was a former smoker with 16 pack years of smoking history and chronic marijuana abuse. He served in marine core, worked as electronic technician his entire life. Pleural fluid studies confirmed exudative effusion based on pleural LDH levels per Lights criteria, culture including AFB and also Adenosine deaminase level was negative. Bronchoscopy and Transbronchial biopsy was inconclusive. Pleural fluid and bronchial brushing cytology was negative for malignant cells. ANA panel was negative. Patient underwent video assisted thoracoscopic surgery with meticulous decortication of the fibrothorax of the right lung. Pleural biopsy showed pleural fibrosis with foci of mesothelial hyperplasia. Due to persistent shortness of breath, repeat CT Chest was done after 12 months of initial presentation which showed a new left sided pleural effusion, multiple pulmonary nodules, pleural metastatic disease, osteolytic lesion in T 10 vertebral body and right 9th rib. Pleural fluid cytology at this time showed atypical cells which warranted biopsy of pleura, osteolytic rib lesion and also subcutaneous nodule. Biopsy showed malignant spindle cells proliferation which on immunohistochemical staining proved to be sarcomatoid mesothelioma.
DISCUSSION: SM is an aggressive and the least common histopathologic type of mesothelioma which is resistant to cancer therapy. Common misdiagnoses for SM include Fibrosarcoma, Fibrous pleurisy, Malignant fibrous histiocytoma, Metastasized renal cell carcinoma, Localized fibrous tumors, Pleural liposarcoma. Work up includes imaging studies and pleural biopsy. Pathological examination shows spindle-shaped cells arranged in a haphazard pattern with plump, elongated nuclei. Sarcomatoid cells stain positive for antibodies including CAM5.2, WT1, podoplanin and D2-40 on immunohistochemistry. The median survival for patients with Sarcomatoid tumors is typically less than six months which makes it even more important to diagnose this disease early.
CONCLUSIONS: A single negative pleural biopsy is not enough to rule out SM. It is important to consider SM as a possible differential of entrapped lung even in patients who do not have asbestosis exposure.
Reference #1: Hammer, Samuel P. "Macroscopic, Histologic, Histochemical, Immunohistochemical, and Ultrastructural Features of Mesothelioma." Society of Ultrastructural Pathology Companion Meeting, 27 February 2005,
DISCLOSURE: The following authors have nothing to disclose: Avantika Chenna, Pradyumna Agasthi, Srinadh Annangi, Eric Flenaugh, Punita Kaveti
No Product/Research Disclosure Information