Gastric carcinoids: Between underestimation and overtreatment

Table 2 Clinicopathological characteristics of endocrine tumors of the stomach according to WHO classification[23]

Well-differentiated tumor-carcinoid

Benign behavior: confined to mucosa-submucosa, non-angioinvasive, ≤ 1 cm in size, non-functioning

ECL cell tumor of corpus-fundus associated with hypergastrinemia and chronic atrophic gastritits (CAG) or MEN1 syndrome

Serotonin-producing tumor

Gastrin-producing tumor

Uncertain behavior: confined to mucosa-submucosa, > 1 cm in size, or angioinvasive

ECL cell tumor with CAG or MEN1 syndrome or sporadic

Serotonin-producing tumor

Gastrin-producing tumor

Well-differentiated endocrine carcinoma-malignant carcinoid

Low-grade malignant, deeply invasive (muscularis propria or beyond), or with metastasis

Nonfunctioning

ECL cell carcinoid, usually sporadic, rarely in CAG or MEN1 syndrome

Serotonin-producing tumor

Gastrin-producing tumor

Functioning

ECL cell carcinoid with atypical carcinoid syndrome

Serotonin-producing carcinoid with syndrome

Gastrin-producing carcinoma-malignant gastrinoma

ACTH-producing carcinoma with Cushing syndrome

Poorly differentiate endocrine carcinoma-small cell carcinoma, high grade malignant, usually non-functioning, occasionally with Cushing syndrome