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A4070 - Large Cell Lung Carcinoma with Rhabdoid Phenotype with a Targetable Mutation
Author Block: Y. Simons, A. I. Velazquez; Icahn School of Medicine at Mount Sinai Beth Israel, New York, NY, United States.
Introduction: The following is a presentation of an exceedingly rare non-small cell lung cancer, large cell lung carcinoma with rhabdoid phenotype, that displayed a targetable mutation uncommon in this malignancy. Case: A 53 year old East-Asian female with a past medical history of asthma presented with four days of progressively worsening shortness of breath with an associated dry cough. She denied tobacco use, hemoptysis, night sweats, or weight loss. No family history of malignancy or blood disorders. On presentation, the patient was afebrile, tachycardic, tachypneic and hypoxic. On exam, she had decreased breath sounds on the right side with dullness to percussion. Initial chest x-ray showed a large right sided pleural effusion with mediastinal shift and emergent thoracentesis was performed with removal of two liters of exudative fluid. A CT chest then showed an abnormal right pleural thickening and several pleural-based nodules concerning for malignancy. Due to repeat fluid accumulation requiring multiple thoracenteses, the patient underwent VATs with decortication and a pleural biopsy. Pathology confirmed a poorly differentiated large cell lung carcinoma with rhabdoid features. Molecular testing revealed that the patient did not harbor an EGFR mutation; however, 62% of cells harbored an ALK rearrangement. Discussion: Large cell lung carcinoma with rhaboid features is a rare and aggressive histologic entity, accounting for 0.1-1% of all lung tumors. It is characterized by the presence of more than 10% cells with rhabdoid morphology-large cells with abundant cytoplasm, eccentric nuclei, prominent nucleoli and eosinophilic cytoplasmic inclusions. This diagnosis portends a poor prognosis due to its rapid progression. Given its rarity, data surrounding the presence of targetable mutations which are common in other non-small cell lung cancers, particularly adenocarcinoma, is limited. A case series analyzing 6 cases of large cell lung carcinoma with rhaboid features identified the presence of a KRAS mutation in 50% of the cases (n=3). Our case displays the importance of genetic analysis in this rare tumor entity for the identification of targetable mutations and subsequent targeted therapy. Conclusion: Given the aggressive nature of this disease, testing for targetable oncogenic alterations should be considered to facilitate an early individualized treatment plan.