Pulmonary Adenomatosis, Ovine: A contagious, neoplastic, pulmonary disease of sheep characterized by hyperplasia and hypertrophy of pneumocytes and epithelial cells of the lung. It is caused by JAAGSIEKTE SHEEP RETROVIRUS.Adenoma, Liver Cell: A benign epithelial tumor of the LIVER.Betaretrovirus: A genus of the family RETROVIRIDAE consisting of viruses with either type B or type D morphology. This includes a few exogenous, vertically transmitted and endogenous viruses of mice (type B) and some primate and sheep viruses (type D). MAMMARY TUMOR VIRUS, MOUSE is the type species.Multiple Endocrine Neoplasia: A group of autosomal dominant diseases characterized by the combined occurrence of tumors involving two or more ENDOCRINE GLANDS that secrete PEPTIDE HORMONES or AMINES. These neoplasias are often benign but can be malignant. They are classified by the endocrine glands involved and the degree of aggressiveness. The two major forms are MEN1 and MEN2 with gene mutations on CHROMOSOME 11 and CHROMOSOME 10, respectively.Intestinal Polyposis: The growth of INTESTINAL POLYPS. Growth processes include neoplastic (ADENOMA and CARCINOMA) and non-neoplastic (hyperplastic, mucosal, inflammatory, and other polyps).Lynestrenol: A synthetic progestational hormone used often in mixtures with estrogens as an oral contraceptive.Duodenal Neoplasms: Tumors or cancer of the DUODENUM.Adenomatosis, Pulmonary: A neoplastic disease in which the alveoli and distal bronchi are filled with mucus and mucus-secreting columnar epithelial cells. It is characterized by abundant, extremely tenacious sputum, chills, fever, cough, dyspnea, and pleuritic pain. (Stedman, 25th ed)Adenomatous Polyposis Coli: A polyposis syndrome due to an autosomal dominant mutation of the APC genes (GENES, APC) on CHROMOSOME 5. The syndrome is characterized by the development of hundreds of ADENOMATOUS POLYPS in the COLON and RECTUM of affected individuals by early adulthood.Intestinal Polyps: Discrete abnormal tissue masses that protrude into the lumen of the INTESTINE. A polyp is attached to the intestinal wall either by a stalk, pedunculus, or by a broad base.Adenoma: A benign epithelial tumor with a glandular organization.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Liver Neoplasms: Tumors or cancer of the LIVER.