owing to the frequent use of electron microscopy examination to differentiate small cell undifferentiated ( oat cell ) carcinomas and , occasionally , other neuroendocrine neoplasms from lymphomas , the finding of these neurosecretory-like structures in lymphomas creates significant difficulty in the differential diagnosis and separation of these neoplasms by ultrastructural analysis .
C0206754
neuroendocrine neoplasms
C0027651
neoplasms