The association of mediastinal mass in the formation of thrombi in pediatric patients with non‐lymphoblastic lymphomas

Background Children diagnosed with cancer are at a significantly higher risk of developing a thrombotic event (TE) compared with the general population. The rarity of these events makes it difficult to discern the specific risk factors; however, age, sex, presence of central venous lines, inherited thrombophilia, and mediastinal mass may play a role. The primary aim of this study is to identify prognostic characteristics of children diagnosed with non-lymphoblastic lymphomas associated with a greater risk of developing a TE early on in their disease, with an increased focus on mediastinal mass characteristics. Methods Retrospective chart review of pediatric patients diagnosed with non-lymphoblastic lymphoma between 2004 and 2014 at St. Jude Children's Research Hospital. Results TE occurred in 8.5% (n = 28/330) of individuals at a median of 21 days from the diagnosis of a non-lymphoblastic lymphoma, with 60% of TEs occurring within 30 days of diagnosis. Of the variables evaluated, only presence of a peripherally inserted central catheter (odds ratio [OR]: 3.14 [95% CI: 1.24-7.98; P = 0.02]) and degree of superior vena cava (SVC) compression of > 25% increased the odds of developing a TE (OR: 2.2 [95% CI: 1.01-4.93; P = 0.048]). Conclusion Pediatric patients with non-lymphoblastic lymphoma are at increased risk of developing TEs. In contrast to previous studies, the presence of a mediastinal mass alone was not associated with a higher risk of TE, but individuals with a mediastinal mass with 25% or greater degree of SVC compression were more likely to develop a TE. This finding highlights a high-risk group of children who may benefit from prophylactic anticoagulation.