Case Presentation: A 94-year-old woman with a history of atrial fibrillation (not on anticoagulation), coronary artery disease, and metastatic lung adenocarcinoma (on Osimertinib) presented following a syncopal episode, which was complicated by a left thigh hematoma. On admission, she was hemodynamically stable, although her bloodwork was concerning for disseminated intravascular coagulation (DIC) including a hemoglobin of 5.9 g/dL (baseline of 9.5), platelets 39 (K/L), D-dimer >60,000 and fibrinogen <50 (mg/dL). She was thought to have DIC due to the thigh hematoma from her fall; she received a total of 5 units of packed red blood cells, 2 units of platelets, and 2 units of cryoprecipitate over the course of her four-day admission. Her labs remained stable and she was discharged home. Osimertinib was held due to concerns that it contributed to her anemia and thrombocytopenia. One week later, the patient returned to the emergency department with syncope. On admission, she was hypotensive with systolic blood pressures in the 80s. Her labs suggested recurrent DIC with a Hb of 5.9 (which was 9.3 on the day of her recent discharge), fibrinogen 68, D-dimer >60,000. Her DIC was thought to be less likely from the prior hematoma and her work-up was not consistent with an infection. Ultimately, this DIC was thought to be a complication of lung adenocarcinoma. After further transfusions, Osimertinib was restarted and she was discharged with plans for close CBC and DIC panel monitoring with her outpatient oncologist.
Discussion: DIC involves the widespread activation of coagulation pathways, which can result in thrombosis as well as hemorrhage. Acute, decompensated DIC involves the consumption of pro-coagulant factors and often involves systemic manifestations such as bleeding and multi-organ dysfunction. Chronic DIC, such as with this patient, may be more insidious and is often associated with malignancy. While this patient was initially thought to have DIC secondary to trauma, continued episodes of DIC raised the question of malignancy as the underlying etiology.
Conclusions: While malignancy is a known risk factor, non-small cell lung cancer is a less commonly associated, but important potential cause of DIC. Other case studies have also started exploring this topic, by identifying patients with coagulopathies such as ischemic stroke, myocardial infarction, or DIC who were later found to have lung cancer. Being able identify DIC as a complication of lung cancer is especially important, as patients with lung cancer who also develop DIC tend to have worse prognoses. Treatment for DIC involves identifying underlying causes; this case highlights the importance of recognizing DIC as an uncommon but serious potential complication of lung cancer, which if identified early on can help redirect care accordingly.