Carcinoid tumor

Carcinoid is a low-grade malignant tumor originating from endocrine cells in the digestive tract and other organs. The cells often exhibit localized, infiltrative, and slow growth. Although the tissue structure resembles cancer and has a tendency for malignancy, metastasis is rare, hence the name "carcinoid." Carcinoid is commonly found in the digestive tract and lungs, and can also be seen in the thymus, thyroid, ovaries, cervix, and testes.