A rare case of biliary adenocarcinoma mimicking an abdominal wall soft tissue tumor.

BACKGROUND

Meckel's diverticulum is a mostly asymptomatic anatomic anomaly of the small intestine. Frequently, ectopic mucosa can be found within, potentially causing complications such as hemorrhage. In 0.5%-3.2% of symptomatic patients with Meckel's diverticula, a neoplasm is found.

METHODS

Here, we report an extremely rare case of ectopic biliary adenocarcinoma arising from the tip of an incompletely detached Meckel's diverticulum and infiltrating the adjacent abdominal wall in a 79-year-old patient. Moreover, we review the literature on the seldom occurrences of adenocarcinoma in Meckel's diverticula and potential treatment strategies.

FINDINGS: Initially believed to be a soft tissue tumor of the abdominal wall, biopsy results showed adenocarcinoma with CA19-9 and CK7 expression. Hence, open surgery with en bloc oncologic small intestine resection was performed. The patient was discharged with normal bowel passage after an unremarkable postoperative period. Adjuvant chemotherapy was recommended; however, to date, no standard treatment for adenocarcinoma arising from a Meckel's diverticulum has been agreed upon.

CONCLUSION

The successful surgical resection and ongoing disease-free survival highlight the importance of recognizing and managing malignancies in ectopic embryonic remnants. This case contributes valuable insight into the diagnosis, behavior, and treatment considerations of ectopic malignancies.

FUNDING: This research has not received any external funding.