title: Clear cell carcinoid of the appendix: Report of two cases with literature review.
abstract: The clear cell/lipid-rich change has been described in neuroendocine tumors in several organs, but rarely observed in the appendix. In this study, we describe the morphologic, immunohistochemical features of incidentally discovered appendiceal carcinoids entirely represented by clear cells in a 22-year-old man and a 52-year-old woman. Ultrastructual examination demonstrated abundant lipid droplets and dense core granules. The mechanism leading to lipid accumulation in the cytoplasm has not been discovered, but degenerative processes following recurrent inflammatory change might be considered. This uncommon variant of appendiceal classic carcinoid tumors may bear a superficial resemblance to goblet carcinoid and/or appendiceal metastases from clear cell carcinoma. Awareness of clear cell carcinoid of the appendix will prevent incorrect diagnosis and unnecessary aggressive management.
authors: Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
authors: Gu Hyum
authors: GH
authors: Kang
authors: Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
authors: Byung Seok
authors: BS
authors: Lee
authors: Department of Pathology, Chungnam National University College of Medicine, Daejeon, Korea.
authors: Dae Young
authors: DY
authors: Kang
mesh_terms: D001063:Appendiceal Neoplasms / Q000378:metabolism / Q000473:pathology*; D001065:Appendix / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002276:Carcinoid Tumor / Q000378:metabolism / Q000473:pathology*; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor
keywords: appendix; carcinoid; clear cell; neuroendocrine tumor