title: Lipid-rich variant of appendiceal well-differentiated endocrine tumor (carcinoid).
abstract: Well-differentiated endocrine tumors (WDETs) of the appendix show characteristic morphologic features, including proliferation of cells with finely granulated eosinophilic cytoplasm. However, clear cell WDETs, which can present a diagnostic challenge, have been occasionally described, but it is unknown whether they represent a morphologic variant with distinct clinicopathologic features. Moreover, the clear cell appearance of the cytoplasm has never been explained. We studied 13 appendiceal WDETs composed of clear cells, which showed an immunophenotype identical to that of conventional appendiceal WDETs. Ultrastructural examination demonstrated abundant lipid accumulation. Patient survival was excellent and equal to that of conventional appendiceal WDETs. These neoplasms, which represent a lipid-rich variant of appendiceal WDETs, do not have different relevant clinical implications compared with conventional WDETs, but it is important to know of their existence for the differential diagnosis with more aggressive neoplasms, including goblet cell carcinoids and appendiceal metastases from clear cell carcinomas.
authors.affiliation: Servizio di Anatomia Patologica, Ospedale di Circolo, Viale Borri 57, 21100 Varese, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: La Rosa
authors.forename: Giovanna
authors.initials: G
authors.lastname: Finzi
authors.forename: Giacomo
authors.initials: G
authors.lastname: Puppa
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
mesh_terms: D000293:Adolescent; D000328:Adult; D001063:Appendiceal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis; D002276:Carcinoid Tumor / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D049109:Cell Proliferation; D002648:Child; D003593:Cytoplasm / Q000737:chemistry / Q000648:ultrastructure; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008055:Lipids / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D008055:Lipids