Juvenile dermatomyositis as a paraneoplastic phenomenon: an update.

Approximately 33% of adult patients with dermatomyositis develop malignancy with up to 42% presenting after the diagnosis has been made; careful evaluation for malignancy is often undertaken at the time of dermatomyositis diagnosis. This phenomenon has rarely been noted in pediatric patients and extensive workup for malignancy is not indicated in pediatric patients. In 1993, 6 cases were reported in which juvenile dermatomyositis/polymyositis (JDM/PM) appeared to be part of a paraneoplastic phenomenon. Our objective was to update the literature for reported cases of malignancy associated with JDM/PM; we reviewed the literature over the last 15 years and located 6 additional cases. In 9 of 12 reported patients an unusual physical finding such as splenomegaly or lymphadenopathy was noted at the time of diagnosis, and in the entire group, the malignancy occurred within a mean of 12 months. It is less likely that JDM/PM in pediatric patients is a paraneoplastic phenomenon as it is in adult patients. However, if the physical examination at the time of diagnosis of JDM/PM is atypical the presence of malignancy must be considered and a more in-depth evaluation to rule out malignancy should be performed prior to the initiation of treatment.