Head K W
Bull World Health Organ. 1976;53(2-3):167-86.
(a) tumours of the gastrointestinal tract; and (b) tumours of the anal canal and margin. In the gastrointestinal tract the tumours are classified as adenoma, adenocarcinoma, and undifferentiated carcinoma, with several subtypes. Most polyps prove to be non-neoplastic, hyperplastic, or regenerative rather than adenomatous. Carcinoma of the stomach occurs mainly in dogs, but is a rare tumour in all parts of the world. Moderately differentiated, tubular adenocarcinoma of the small intestine with excessive fibrosis occurs in all six species; in some geographical locations it may occur frequently in sheep and cattle. The adenoma/carcinoma sequence in the rectum of the dog is similar to that in man but is encountered less often. Carcinoid tumours are very rare in domestic animals. Among the soft tissue tumours, those of smooth muscle and adipose tissue are found fairly frequently and congenital mesothelioma in the peritoneum of calves occurs occasionally. Tumours of the haematopoietic and related tissues are the most common gastrointestinal neoplasms in all species and most belong to the lymphosarcoma group. Tumours of the anal canal and margin are common in the dog and 90% of these are tumours of the hepatoid (perianal) glands.
(a) 胃肠道肿瘤；(b) 肛管及边缘肿瘤。在胃肠道中，肿瘤分为腺瘤、腺癌和未分化癌，还有几个亚型。大多数息肉被证明是非肿瘤性、增生性或再生性的，而非腺瘤性。胃癌主要发生在犬类中，但在世界各地都是一种罕见的肿瘤。小肠中度分化的管状腺癌伴过度纤维化在所有六个物种中都有发生；在某些地理位置，它可能在绵羊和牛中频繁出现。犬直肠中的腺瘤/癌序列与人类相似，但较少见。类癌肿瘤在家畜中非常罕见。在软组织肿瘤中，平滑肌和脂肪组织的肿瘤相当常见，小牛腹膜中的先天性间皮瘤偶尔会出现。造血及相关组织的肿瘤是所有物种中最常见的胃肠道肿瘤，大多数属于淋巴肉瘤组。肛管及边缘肿瘤在犬类中很常见，其中90%是肝样（肛周）腺肿瘤。
