Goblet Cell Carcinoid Is a Morphologic Variant of Appendiceal Mucinous Neoplasms: Lesson From Concurrent Dissemination in Pseudomyxoma Peritonei

Le résumé fourni par la source

The nature and histogenesis of goblet cell carcinoid (GCC) is still inconclusive. Coexistence of appendiceal GCC and mucinous cystadenoma is reported in rare cases. In our experience, a concurrent dissemination of GCC and various appendiceal mucinous neoplasms (AMNs) is sometimes seen in the development of pseudomyxoma peritonei (PP), suggesting a link between these entities. This case series describes the association of these different morphologies. Nine cases of PP (4 men, 5 women;, 32-73 years old) treated with surgical cytoreduction were assessed for morphologic components characteristic of GCC, low-grade mucinous neoplasm (LMN), mucinous adenocarcinoma (MCA), and nonmucinous conventional adenomcarcinoma (NMCA) as defined by the WHO classification. The number of different specimens involved by each component was counted in each case. The extent of each component was semiquantitated (0, none; 1, seen in <1 HPF; 2, seen in >1 HPF to 1 LPF; 3, seen in 1-3 LPFs; 4, seen in >3 LPFs). In 6 cases, a primary appendiceal tumor was identified (2 GCC, 1 GCC + MCA, 2 GCC + MCA + NMCA, 1 NMCA). In the remaining 3 cases, the appendix was missing, and no histologic data of previous appendectomy were available. GCC and/or other components were coexistent at different sites in variable combinations. Overall, GCC was the predominant morphology. GCC is coexistent with various mucinous neoplasms (low-and high-grade) or conventional adenocarcinoma in the evolution of PP secondary to AMN. The histologic grade of the primary appendiceal tumor and that of its metastasis are often discordant. Any AMN can present with a wide morphologic spectrum in a single case. Tumor stem cells of any AMN have potential to switch tumor differentiation into different and multiple lineages without site or stage specificity, and GCC can be considered a morphologic variant of malignant AMN.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.