Neuroendocrine differentiation in human gastric carcinoma.
BACKGROUND
Distinguishing between neuroendocrine carcinoma and adenocarcinoma may be difficult.


METHODS
In the current prospective study blood and tumor tissue from patients with gastric carcinoma were collected. The tissue was fixed in different ways to allow examination for neuroendocrine markers by multiple methods such as various histochemical and immunohistochemical methods and electron microscopy. Blood and tumor homogenates were examined by radioimmunoassay for specific hormones and general neuroendocrine markers.


RESULTS
Based on examination of general neuroendocrine markers such as chromogranin A (by immunohistochemistry, Northern blot analysis, and tissue concentration), neuron specific enolase (immunohistochemistry) as well as electron microscopy, it was possible to conclude that approximately 10% of the tumors were actually neuroendocrine malignant tumors. Among these tumors, the enterochromaffin-like (ECL) cell was the most preponderant cell of origin (Sevier-Munger positive and serotonin negative immunoreactive tumor cells with secretory granules resembling those observed in normal ECL-cells). As reported previously, tumors of the diffuse type (according to the classification of Laurén) most often were reclassified as neuroendocrine carcinomas.


CONCLUSIONS
The current study shows that neuroendocrine and particularly ECL cell-derived tumors are more common in the stomach than previously recognized.
Department of Medicine, University Hospital of Trondheim, Norway.
H L
HL
Waldum
S
S
Aase
I
I
Kvetnoi
E
E
Brenna
A K
AK
Sandvik
U
U
Syversen
G
G
Johnsen
L
L
Vatten
J M
JM
Polak
D000230:Adenocarcinoma / Q000145:classification; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis / Q000235:genetics; D004759:Enterochromaffin Cells / Q000648:ultrastructure; D005260:Female; D005755:Gastrins / Q000097:blood; D006632:Histamine / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000145:classification*; D010187:Pancreatic Hormones / Q000032:analysis; D011446:Prospective Studies; D012333:RNA, Messenger / Q000032:analysis; D013274:Stomach Neoplasms / Q000737:chemistry / Q000145:classification* / Q000648:ultrastructure
D053379:Chromogranin A; D002864:Chromogranins; D005755:Gastrins; D010187:Pancreatic Hormones; D012333:RNA, Messenger; C050836:pancreastatin; D006632:Histamine