Lorvotuzumab Mertansine in Treating Younger Patients With Relapsed or Refractory Wilms Tumor, Rhabdomyosarcoma, Neuroblastoma, Pleuropulmonary Blastoma, Malignant Peripheral Nerve Sheath Tumor, or Synovial Sarcoma

Inclusion Criteria: * Patients must have had histologic verification of one of the malignancies listed below at original diagnosis or at relapse * Primary strata * Wilms tumor * Rhabdomyosarcoma * Neuroblastoma * Secondary strata: miscellaneous CD56-expressing tumors: * Pleuropulmonary blastoma * Malignant peripheral nerve sheath tumor (MPNST) * Synovial sarcoma * Patients must have radiographically measurable disease (with the exception of those with neuroblastoma) * Measurable disease is defined as the presence of at least one lesion on magnetic resonance imaging (MRI) or computed tomography (CT) scan that can be accurately measured with the longest diameter a minimum of 10 mm in at least one dimension (CT scan slice thickness no greater than 5 mm) * Note: the following do not qualify as measurable disease: * Malignant fluid collections (e.g., ascites, pleural effusions) * Bone marrow infiltration except that detected by metaiodobenzylguanidine (MIBG) scan for neuroblastoma * Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography \[PET\] scans) except as noted in patients with neuroblastoma who do not have measurable disease but have MIBG-avid evaluable disease * Elevated tumor markers in plasma or cerebrospinal fluid (CSF) * Previously radiated lesions that have not demonstrated clear progression post radiation * Leptomeningeal lesions that do not meet the measurem…