Adenocarcinoid, a mucin-producing carcinoid tumor of the appendix. A study of 39 cases

Abstract

Adenocarcinoid is a form of appendiceal carcinoid possessing features of both carcinoid and adenocarcinoma. There are two histologic types. Thirty patients had the goblet cell type, characterized by nests of large mucin-distended cells. Nine patients had the tubular type, characterized by small glandular structures lined by uniform cells. Despite abundant mucin and a goblet cell or acinar-like arrangement, a closer relationship to carcinoid than to adenocarcinoma is suggested by a concentration of tumor elements below the crypts of Lieberkuhn, a lack of evidence of neoplastic transformation of the appendiceal mucosa, and the demonstration of argentaffin or argyrophil granules in 88% of the lesions. Six tumors, all of the goblet cell type, metastasized and resulted in the death of the patients. One of the tumours that metastasized had a prominent tubular component. Most adenocarcinoids can be adequately treated by appendectomy, but hemicolectomy is recommended for those tumors showing atypical foci, a high mitotic count, or spread beyond the appendix.

Goblet Cell Carcinoid Tumor, Mixed Goblet Cell Carcinoid-Adenocarcinoma, and Adenocarcinoma of the Appendix: Comparison of Clinicopathologic Features and Prognosis

“…Some studies 14,20,24,38 advocate further surgery in all patients, whereas others suggest additional resection only for patients with positive margins, significant atypia, increased mitoses (2 per 10 high-power fields), increased Ki-67 staining (.3%), clinically involved lymph nodes, or metastatic disease. 5,8,11,18,[26][27][28]39 In our study, 14 of 30 patients (47%) with tumors containing a GCT component had residual disease in right colectomy specimens, either in the intestinal wall, the peri-intestinal soft tissue, and/or lymph nodes, including 36% (5 of 14) of the patients in group 1. This greater frequency of residual disease may represent a referral bias at our institution.…”

“…2,5,18 In the mostrecent, large study of these tumors, Tang et al 35 found a 77% overall disease-specific survival among 63 patients with GCT, which was more favorable than the survival of a control group of 28 conventional appendiceal adenocarcinomas, even when comparing only patients with stage IV disease. However, it is well-known that GCTs do not behave uniformly, and cases with a more-aggressive course have been described.…”

“…2015;139:782-790; doi: 10.5858/ arpa.2013-0047-OA) G agné et al 1 are credited with recognizing appendiceal tumors with both argentaffin-positive and mucinproducing cells in 1969. Goblet cell carcinoid tumor (GCT)-also termed mucinous carcinoid tumor, 2 mixed crypt cell carcinoma, 3,4 adenocarcinoid-goblet cell type, 5,6 and microglandular goblet cell carcinoma 7 -is a unique neoplasm occurring almost exclusively in the appendix. The classic histologic features of GCTs are those of a tumor composed of multiple cell types (predominately goblet cells, a few neuroendocrine cells, and occasional Paneth cells), arranged as discrete nests arising in the deep lamina propria and involving the wall of the appendix in a concentric fashion.…”

“…The classic histologic features of GCTs are those of a tumor composed of multiple cell types (predominately goblet cells, a few neuroendocrine cells, and occasional Paneth cells), arranged as discrete nests arising in the deep lamina propria and involving the wall of the appendix in a concentric fashion. 3,5,[8][9][10] The GCTs' organoid growth pattern, presence of scattered neuroendocrine cells, ultrastructural evidence of neurosecretory granules, lack of cytologic atypia, lack of p53 mutations, and lack of an in situ mucosal precursor lesion have compelled many authors to consider GCTs as a type of carcinoid tumor. 2,5,[11][12][13][14][15] In addition, rare tumors with both GCT and classic carcinoid tumor components have been described.…”

“…3,5,[8][9][10] The GCTs' organoid growth pattern, presence of scattered neuroendocrine cells, ultrastructural evidence of neurosecretory granules, lack of cytologic atypia, lack of p53 mutations, and lack of an in situ mucosal precursor lesion have compelled many authors to consider GCTs as a type of carcinoid tumor. 2,5,[11][12][13][14][15] In addition, rare tumors with both GCT and classic carcinoid tumor components have been described. 16 However, the presence of intracellular mucin and characteristic transcoelomic spread with frequent metastases-including ovarian involvement in womenare features more in keeping with adenocarcinoma, or at least an entity distinct from classic carcinoid tumor.…”