A Rare Tumor of Pleura in a Gentleman From Afghanistan

Abstract

INTRODUCTION: Pulmonary Sarcomatoid carcinomas (PSC) are rare, poorly-differentiated variants of Non-small cell lung cancers (NSCLC) that comprise 0.3-3% of all primary lung neoplasms. Diagnosis of PSC mainly relies on light microscopy while Immunohistochemical (IHC) panel lacks definitive role for diagnostic confirmation CASE PRESENTATION: A 60-year-old Afghan male, construction worker, presented through ED with 4 years history of intermittent chest pain, shortness of breath, cough and low-grade fever. He was a never smoker. He denied family history of TB and lung cancers. On physical exam, his respiratory rate was 28 bpm with oxygen saturation 87% on room air and decreased breath sounds on right side of the chest. His Chest X-ray (Fig 1 ) showed right sided diffuse infiltrates and opacification. CT chest (Fig 2A , 2B) showed circumferential nodular soft tissue encasement of right lung, likely pleural based with volume loss. CT-guided biopsy was performed. Microscopic examination (Fig3A, 3B, 3C, 3D) showed a biphasic neoplastic lesion composed predominantly of epithelioid to spindle shaped, moderately pleomorphic, hyperchromatic to vesicular nuclei, prominent nucleoli and eosinophilic to clear cytoplasm and a minor component exhibiting glandular architecture. An IHC panel was performed that showed diffuse positive expression of Cytokeratin (CK) AE1/AE3, CAM 5.2 and TLE-1 in both neoplastic components. Cytokeratin 7 and 19 positivity was seen only in glandular component. Negative markers included BerEp4, TTF-1, Napsin-A, Synaptophysin, Desmin, Inhibin, CDX-2, Hep-Par1 and Calretinin. Cytogenetic for translocation t (X; 18) was negative for synovial sarcoma. He was diagnosed as Sarcomatoid carcinoma. He preferentially wanted to be treated in his country so his outcome remains unknown DISCUSSION: SC of lung are defined as de-differentiated NSCLC with both sarcoma, and sarcoma-like differentiation. World Health Organization has divided SC into 5 subtypes including Spindle cell carcinoma, Giant cell carcinoma, Pleomorphic carcinoma, Carcinosarcoma and Biphasic pulmonary blastoma. Majority of patients are elderly, smokers, presenting with nonspecific symptoms and a peripheral mass with well-defined margins. Prognosis is dismal. Lucas et al. study concluded the limited utility of IHC after carrying out a panel that included pan-cytokeratin, CK5/6, calretinin, WT1, Thrombomodulin and Smooth muscle actin. Baldovini et al. highlighted that CK-7 is a sensible marker for spindle/giant cell component and TTF-1 carries higher sensitivity than Napsin-A for sarcomatoid carcinomas. Chromosomal translocation t (X; 18) has been seen in >90% synovial sarcomas. CONCLUSIONS:In our opinion, the combination of relevant clinical history, radiologic imaging, appropriate immunohistochemical markers and cytogenetics are key in differentiating closely related sarcomatoid carcinomas, true sarcomas and sarcomatoid mesotheliomas