Signet ring cell carcinoma of the appendix and terminal ileum: A case report.

BACKGROUND: Appendiceal signet-ring cell carcinoma (SRCC) with terminal ileum metastasis is extremely rare. There have been no reported cases in domestic and foreign literature.

CASE SUMMARY: In this case report, we present an 88-year-old man with appendiceal SRCC with terminal ileum metastasis. The tumour stage was stage pT4bN2M1bG3 IVB, and the Tumour, Node, Metastasis staging system was used. The patient was admitted to our hospital on 12 July, 2022 and underwent laparoscopic appendectomy under general anaesthesia after the examination. The pathological examination that took place 1 week after the operation showed that SRCC of the appendix invaded the whole layer, vessels and nerves of the appendix wall. It was suggested that the primary appendix should be considered after excluding metastasis. Based on the postoperative pathology findings, the patient underwent a secondary surgery on 2 August, 2022. The second pathological examination showed residual SRCC in the appendiceal area of the ileocecal region, which infiltrated the serosal fibres and adipose tissue of the ileocecal region to the surface mesothelium. The tumour infiltrated the whole layer of the ileum wall, serosa fibres, adipose tissue and the surface mesothelium. Postoperative follow-up showed no signs of tumour recurrence or metastasis.

CONCLUSION: In clinical practice, a heightened awareness of rare diseases, coupled with thorough intraoperative exploration and rapid pathological examination, enables more accurate judgments, potentially sparing patients from unnecessary secondary surgery and ensuring optimal treatment.