Histological, immunohistochemical, ultrastructural and biochemical study of human gastric composite tumor: expression of the serotonin-2B receptor by the neuroendocrine component.
We report a case of a human gastric composite tumor occurring seven years after a partial gastrectomy for a low grade B cell MALT lymphoma. Histological examination of the tumor revealed two intimately intermingled components: 1. A moderately to poorly differentiated tubulo-acinar adenocarcinoma with signet-ring cells; and 2. Isolated or clustered small neuroendocrine cells without atypia expressing chromogranin A, somatostatin and/or glucagon, serotonin (5-HT) and, the 5-HT2B receptors. In addition to immunohistochemical detection, the presence of 5-HT2B receptors was shown pharmacologically through [125I]-DOI binding. Since 5-HT2B receptors have been demonstrated to have autocrine functions and, mitogenic and transforming properties, these results suggest a role of 5-HT in neuroendocrine malignant transformation. On the other hand, the expression of somatostatin and the detection by reverse transcriptase polymerase chain reaction (RT-PCR) of somatostatin receptor subtypes 2, 3, and 5, which have been shown to be involved in tumor regression, might account for the long evolution of this case (> 5 yr). This case illustrates the importance of local humoral modulation in tumor growth. Moreover, ultrastructural results favor a unique origin of the tumor cells from one amphicrine cell type.
Brouland
J P
JP
Service d'Anatomie et de Cytologie Pathologiques (J-PB, IB-S, MW, AL), Hôpital Lariboisière, AP-HP, 75475 Paris, France. jean-philippe.brouland@lrb.ap-hop-paris.fr
Manivet
P
P
Brocheriou-Spelle
I
I
Wassef
M
M
Le Bodic
M F
MF
Lavergne
A
A
Launay
J M
JM
D000230:Adenocarcinoma / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005260:Female; D005934:Glucagon / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D018358:Neuroendocrine Tumors / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D044403:Receptor, Serotonin, 5-HT2B; D011985:Receptors, Serotonin / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017481:Receptors, Somatostatin / Q000032:analysis / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000032:analysis / Q000378:metabolism; D013004:Somatostatin / Q000032:analysis / Q000145:classification / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology
D053379:Chromogranin A; D002864:Chromogranins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D044403:Receptor, Serotonin, 5-HT2B; D011985:Receptors, Serotonin; D017481:Receptors, Somatostatin; D012701:Serotonin; D013004:Somatostatin; D005934:Glucagon