Appendectomy: Signet ring Adenocarcinoma, ex-goblet cell carcinoid.
Tumor greatest dimension (diameter): 2 mm
Location: tip of appendix
Depth of invasion: Intramucosal only. No evidence of involvement of submucosa, muscularis or serosa.
Surgical Margins: proximal surgical margin uninvolved. Mesenteric surgical margin uninvolved.
Regional lymph nodes: grossly or microscopically not identified.
Lymphvascular or perineural invasion: Not identified.
pTNM: pTis (intramucosal tumor with invasion of the lamina propria only). Submucosa uninvolved.
This is a mixed goblet cell Carcinoid/signet ring adenocarcinoma. It appears to be a high grade goblet cell Ca evolving to a signet ring adenoCa. There are multiple individual signet ring cells with only occasional cohesive nests and no obvious tubular formation. The singne ring cells ase positive for CEA, CK20, chromogranin A, synaptophysin and CD56. Tumoral cells show a high ki67 proliferation rate close to 100% and also positive p53 stain.
In this particular case, with only a minute focus of intramucosal involvement, the possibility of metastasis or extension to other organs is very low, but the metastatic index of Invasive Adenoca, ex Goblet Cell Ca is described around 10-20%. Some surgeons approach these cases with hemicolectomy.