Rectal goblet cell carcinoid. Primary tumor or metastasis?

Goblet cell carcinoids are biphasic neoplasms of the gastrointestinal tract composed of a glandular and neuroendocrine differentiation. Typically, goblet cell carcinoids are localized in the vermiform appendix. We report the case of a 60-year-old female patient with the diagnosis of a 1.2-cm rectal goblet cell carcinoid tumor discovered during prophylactic proctocolonoscopy. Because of the known aggressive behavior of this entity, a rectosigmoidectomy was performed. The preoperative staging revealed neither local nor systemic spread. After 8 months, the patient is in good health. As a primary tumor of the extraappendiceal gastrointestinal tract, goblet cell carcinoids are a rarity. It is generally recommended to exclude metastasis of a primary appendiceal neoplasm. However, since the patient underwent an appendectomy in 1974, primary origin in the rectum is favored.