Am J Med Sci. 2021 May 11:S0002-9629(21)00169-5. doi: 10.1016/j.amjms.2021.01.027. Online ahead of print.
Hematological paraneoplastic syndromes are fairly uncommon. While mild leukocytosis in solid tumors is well reported, white blood cell (WBC) count over 50,000 u/L, described as paraneoplastic leukemoid reaction (PLR), is not. Indeed, when found, it is usually associated with a higher burden of disease, tumor activity and worse clinical outcomes. We report the case of a challenging and burdensome diagnosis of a presumptive hematological paraneoplastic syndrome in a patient with a locally advanced lung cancer admitted in the Internal Medicine ward. After the end of chemotherapy, clinical and laboratory benefit was observed; however, the aggressive course of the disease became clear, with progression and downhill course that was unresponsive to treatment.