Paraneoplastic leukemoid reaction in a patient with metastatic adenocarcinoma of the lung

Case Report: Hematologic Recovery Following Stereotactic Ablative Radiotherapy in a Patient With Early-Stage Non-Small Cell Lung Cancer and Paraneoplastic Myelofibrosis

Herein, we report the first case presentation of paraneoplastic myelofibrosis associated with cancer. Paraneoplastic syndromes occur in some patients with thoracic malignancies; however, myelofibrosis is not commonly seen in non-small cell lung cancer (NSCLC). We report a case of myelofibrosis in a patient with a new diagnosis of NSCLC that resolved after stereotactic ablative radiotherapy (SABR). In conclusion, NSCLC may evoke unexpected systemic effects that resolve with treatment.

Metastatic BRAF V600E-Mutated Adenocarcinoma of the Lung Presenting as Extreme Neutrophilia and Eosinophilia

Hematologic paraneoplastic syndromes with extreme neutrophilia and eosinophilia are very rarely associated with adenocarcinoma of the lung. We describe a case of a 57-year-old female who presented with neutrophil- and eosinophil-predominant hyperleukocytosis and hypoxic respiratory insufficiency. Bone marrow biopsy confirmed metastatic adenocarcinoma, similar to the biopsy-proven adenocarcinoma of the lung. She was administered one dose of cytotoxic chemotherapy with carboplatin and pemetrexed and started on leukoreductive therapy with hydroxyurea. Molecular testing revealed a BRAF V600E mutation and she was started on dabrafenib and trametinib with significant clinical improvement. This is the first reported case of metastatic BRAF V600E mutated non-small cell lung cancer presenting with extreme neutrophilia and eosinophilia treated with a combination BRAF and mitogen-activated extracellular kinase (MEK) inhibitor.