in addition , certain other neuroendocrine tumors ( neuroblastoma , bronchial and midgut carcinoid tumors ) lacked beta 2m expression , whereas some ( pheochromocytoma , medullary thyroid carcinoma , and peripheral neuroectodermal tumors ) usually stained positively .
C0027819
neuroblastoma
C0684337
peripheral neuroectodermal