Myeloproliferative neoplasms in adolescents and young adults.

Myeloproliferative neoplasms (MPNs) are clonal stem cell disorders commonly diagnosed in the seventh decade of life. With increasing access to blood surveillance, the number of adolescent and young adults (AYAs) diagnosed with MPNs is increasing. AYAs represent a unique cohort of MPN patients with differing challenges and psychosocial needs. The majority of AYA patients are females diagnosed with essential thrombocythaemia and most are asymptomatic at diagnosis. There is a striking predisposition to venous thrombotic events with a significant number experiencing splanchnic venous thrombosis (up to 70% of venous events). When compared to older patients, AYAs appear to have an indolent disease course. Interferon is the preferred cytoreductive agent in this population; indications for commencing treatment mirror those of older adults and are determined by the presence of high-risk features for thromboembolic events.