Here we present a case of metastatic PNET which arose from an immature teratoma that was refractory to standard Ewing sarcoma chemotherapy. This PNET was determined to have elevated levels of ALK protein via IHC. The patient was treated with crizotinib on a palliative basis with a sustained response.

Proteus syndrome (PS) is a complex disorder characterized by variable clinical findings of overgrowth and tumor susceptibility. This report presents the first known association between PS and an ovarian germ cell tumor in an adolescent with immature teratoma. A review of the diagnosis of PS and associated tumors is included.

Pleuropulmonary blastoma (PPB) is the most common primary lung tumor of childhood and is associated with somatic or germline DICER1 variants. Recurrent PPB, especially with brain metastases, are difficult to treat and survival is poor. Comprehensive genomic analyses of PPB have been limited in number and depth. The cases presented here identified additional oncogenic drivers from tumor sequencing that could be modulating tumor progression and response to therapy outside of known DICER1 mutations highlighting the need for upfront genomic analysis on all patients with PPB.