Soft-tissue sarcomas are extremely rare, with an estimated 11 930 new cases in the United States in 2015, representing less than 1% of all new cancer cases.1 They are a heterogeneous group of diseases with more than 80 different histologic types and subtypes that have widely different clinical behaviors and outcomes.2 Leiomyosarcomas involving the inferior vena cava (IVC) are the rarest of the rare; even at tertiary referral centers, no more than approximately 1 case per year is seen.3 In this issue of JAMA Surgery, Roland et al4 describe one of the largest single-institution reviews of leiomyosarcomas arising from the IVC and other vessels, adding to our very limited understanding of these rare diseases.
Nakakura EK. Finding the Common Thread in Rare Diseases. JAMA Surg. 2016;151(4):355. doi:10.1001/jamasurg.2015.4215