Paraneoplastic Galactorrhea in Childhood T-ALL: An Evaluation of Tumor-derived Prolactin.

T-cell acute lymphoblastic leukemia (T-ALL) comprises 15% of childhood leukemia. Although multiagent pulse chemotherapy has improved event-free survival in recent decades, the lack of reliable prognosticators and high rate of relapse remain a challenge. Described is a novel discovery of tumor-derived hyperprolactinemia in childhood T-ALL through a case associated with paraneoplastic galactorrhea. Prolactin production by tumor cells, although a rare phenomenon, is previously demonstrated in several adult cancers and 2 pediatric malignancies with unknown implications. This is the first report demonstrating tumor-derived prolactin in pediatric T-ALL and offers potential as a disease marker and therapeutic drug target.