The APUD system is a recently defined series of cells which
have endocrine functions in that they secrete one of a variety
of small amine or polypeptide hormones. The stored forms of
these hormones located in the cytoplasm are small, dense-core
membrane-bound granules visible by electron microscopy. Some
of these cells appear to be derived from neural crest cells
which migrate into a variety of organs.
| Tissue |
Benign
Tumors |
Malignant
Tumors |
| Pituitary |
Basophilic
adenoma
Eosinophilic adenoma
Chromophobe adenoma |
--------
--------
-------- |
| Parathyroid |
Parathyroid
adenoma |
Parathyroid
carcinoma |
| Thyroid
(C cells) |
C
cell hyperplasia |
Medullary
carcinoma of thyroid |
Bronchial
lining
(Kultschitzky cells) |
-------- |
Bronchial
carcinooid; oat cell carcinoma |
Adrenalmedulla
Pheochromocytoma |
Pheochromocytoma |
Malignant
Pheochromocytoma |
| Pancreas |
Islet
celladenoma;
Insulinoma; gastrinoma |
Islet
cell carcinoma |
| Stomach
and intestines |
Carcinoid |
Malignant
carcinoid |
| Carotid
body and chemo-receptor system |
Chemodectoma;
paraganglioma |
Malignantcarcinoid
Malignant paraganglioma |
