The demonstration of a subset of carcinoid tumours of the appendix by in situ hybridization using synthetic probes to proglucagon mRNA.
Previous studies using immunohistochemistry have shown variable hormone production by carcinoid tumours of the appendix. In order to confirm the existence of a specific subset of these tumours, in situ hybridization using synthetic oligonucleotide probes to detect pre-proglucagon and pre-proinsulin mRNA was performed in formalin-fixed, paraffin-embedded material from eight tubular carcinoids, 12 insulin carcinoids, and two mucinous carcinoids. The results were correlated with standard silver and mucin stains. All tubular carcinoids but none of the insular or mucinous carcinoids contained proglucagon mRNA. Proinsulin mRNA was not detected in any of the tumours. Tubular carcinoids of the appendix constitute a definable subset of appendiceal carcinoids which have a similar distribution and prognosis to typical insular carcinoids and can be diagnosed on haematoxylin and eosin-stained sections confirmed by routine special stains. The main need for recognition is to avoid confusion with mucinous carcinoids, which have a worse prognosis and may require more aggressive treatment.
Shaw
P A
PA
Department of Histopathology, Leicester Royal Infirmary, U.K.
Pringle
J H
JH
D001063:Appendiceal Neoplasms / Q000737:chemistry / Q000473:pathology*; D002276:Carcinoid Tumor / Q000737:chemistry / Q000473:pathology*; D005934:Glucagon / Q000032:analysis; D006801:Humans; D009693:Nucleic Acid Hybridization; D052336:Proglucagon; D011384:Proinsulin / Q000032:analysis; D011498:Protein Precursors / Q000032:analysis; D015347:RNA Probes; D012333:RNA, Messenger
D011498:Protein Precursors; D015347:RNA Probes; D012333:RNA, Messenger; D052336:Proglucagon; D005934:Glucagon; D011384:Proinsulin