Goblet Cell Carcinoid of the Vermiform Appendix with Ovarian Metastasis Mimicking Mucinous Cystadenocarcinoma

We describe a case of goblet cell carcinoid of the vermiform appendix, which metastasized to the bilateral ovaries, uterus, vagina and peritoneum three years and four months after appendectomy. The appendiceal tumor showed transmural infiltration of carcinoembryonic antigen-positive goblet cell-type tumor cells, intermingled with a small number of argyrophilic cells immunoreactive for serotonin and chromogranin A. The presence of neurosecretory-type granules was confirmed ultrastructurally in some mucin-negative tumor cells. The pattern of proliferation was typical of carcinoid tumor originating from the lower-most part of the mucosa, and showed lymphatic permeation. The metastatic lesions in the pelvic organs showed either diffuse infiltration of goblet cell-type tumor cells or mucinous cystadenocarcinoma-like features, the latter being evident in the right ovary. No neuroendocrine component was identified in the metastatic deposits. The kinship of appendiceal goblet cell carcinoid to adenocarcinoma is discussed.