An unusual primary malignant tumor of the stomach: fetal gutlike gastric adenocarcinoma with "blastoma"-like component.
An unusual case of a polypoid, malignant gastric tumor in a 62-year-old man is presented. Endoscopy and subsequent polypectomy revealed an 8.5 × 6.5 × 4.5-cm lesion in the body of the stomach. Microscopy showed surface dysplasia with an invasive adenocarcinoma displaying prominent tubulopapillary areas composed of large vacuolated cells, pleomorphic nuclei, and occasional cytoplasmic hyaline globules. This component then blended with tubular structures lined by more primitive-appearing vacuolated cells embedded within a stroma made up of cellular primitive, high-grade blastemalike areas and less cellular, more pleomorphic foci with spindle and several bizarre, large cells. Immunohistochemistry showed the adenocarcinoma and primitive tubules to be strongly SALL4 and epithelial marker positive but with only focal expression of α-fetoprotein and glypican-3. The stromal component made up of blastemalike areas displayed strong immunoreactivity for glypican-3. The pleomorphic stromal areas were negative for all markers, including epithelial and muscle markers. The overall morphology and expression of primitive oncofetal proteins, especially SALL4 and glypican-3, are in keeping with this being a primitive adenocarcinoma showing fetal gutlike differentiation with an accompanying blastomalike component, a combination not previously described in a primary gastric cancer.
Department of Pathology, Health Sciences Centre, Eastern Health and Memorial University Newfoundland, St John's, Newfoundland and Labrador A1B 3V6, Canada.
Altaf
A
Taher
Department of Pathology, Health Sciences Centre, Eastern Health and Memorial University Newfoundland, St John's, Newfoundland and Labrador A1B 3V6, Canada.
Nebojsa
N
Denic
Department of Pathology, Laboratory Medicine Programme, University Health Network and University of Toronto, Toronto, Ontario M5G 2C4, Canada.
Sangeetha N
SN
Kalimuthu
Department of Pathology, Laboratory Medicine Programme, University Health Network and University of Toronto, Toronto, Ontario M5G 2C4, Canada. Electronic address: runjan.chetty@gmail.com.
Runjan
R
Chetty
D000230:Adenocarcinoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D002454:Cell Differentiation; D018240:Endodermal Sinus Tumor / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D053673:Glypicans / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018193:Neoplasms, Complex and Mixed / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D013274:Stomach Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014157:Transcription Factors / Q000032:analysis; D000509:alpha-Fetoproteins / Q000032:analysis
C097353:AFP protein, human; D014408:Biomarkers, Tumor; C105937:GPC3 protein, human; D053673:Glypicans; C472575:SALL4 protein, human; D014157:Transcription Factors; D000509:alpha-Fetoproteins
Blastemalike; Gastric cancer; Glypican-3; Primitive tubules; SALL4; Stem cells