Cystadenoma: A benign neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. In some instances, considerable portions of the neoplasm, or even the entire mass, may be cystic. (Stedman, 25th ed)Cystadenoma, Mucinous: A multilocular tumor with mucin secreting epithelium. They are most often found in the ovary, but are also found in the pancreas, appendix, and rarely, retroperitoneal and in the urinary bladder. They are considered to have low-grade malignant potential.Cystadenoma, Serous: A cystic tumor of the ovary, containing thin, clear, yellow serous fluid and varying amounts of solid tissue, with a malignant potential several times greater than that of mucinous cystadenoma (CYSTADENOMA, MUCINOUS). It can be unilocular, parvilocular, or multilocular. It is often bilateral and papillary. The cysts may vary greatly in size. (Dorland, 27th ed; from Hughes, Obstetric-Gynecologic Terminology, 1972)Cystadenoma, Papillary: A benign neoplasm of the ovary.Cystadenocarcinoma: A malignant neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. The neoplastic cells manifest varying degrees of anaplasia and invasiveness, and local extension and metastases occur. Cystadenocarcinomas develop frequently in the ovaries, where pseudomucinous and serous types are recognized. (Stedman, 25th ed)Appendiceal Neoplasms: Tumors or cancer of the APPENDIX.Mucocele: A retention cyst of the salivary gland, lacrimal sac, paranasal sinuses, appendix, or gallbladder. (Stedman, 26th ed)Biliary Tract Neoplasms: Tumors or cancer in the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Bile Duct Neoplasms: Tumors or cancer of the BILE DUCTS.Appendix: A worm-like blind tube extension from the CECUM.Adenoma, Bile Duct: A benign tumor of the intrahepatic bile ducts.Cysts: Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Sertoli-Leydig Cell Tumor: A sex cord-gonadal stromal tumor consists of LEYDIG CELLS; SERTOLI CELLS; and FIBROBLASTS in varying proportions and degree of differentiation. Most such tumors produce ANDROGENS in the Leydig cells, formerly known as androblastoma or arrhenoblastoma. Androblastomas occur in the TESTIS or the OVARY causing precocious masculinization in the males, and defeminization, or virilization (VIRILISM) in the females. In some cases, the Sertoli cells produce ESTROGENS.Bile Ducts, Intrahepatic: Passages within the liver for the conveyance of bile. Includes right and left hepatic ducts even though these may join outside the liver to form the common hepatic duct.Pancreatic Neoplasms: Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).Adenolymphoma: A benign tumor characterized histologically by tall columnar epithelium within a lymphoid tissue stroma. It is usually found in the salivary glands, especially the parotid.Cystadenocarcinoma, Mucinous: A malignant cystic or semisolid tumor most often occurring in the ovary. Rarely, one is solid. This tumor may develop from a mucinous cystadenoma, or it may be malignant at the onset. The cysts are lined with tall columnar epithelial cells; in others, the epithelium consists of many layers of cells that have lost normal structure entirely. In the more undifferentiated tumors, one may see sheets and nests of tumor cells that have very little resemblance to the parent structure. (Hughes, Obstetric-Gynecologic Terminology, 1972, p184)Cecal Diseases: Pathological developments in the CECUM.Hepatic Duct, Common: Predominantly extrahepatic bile duct which is formed by the junction of the right and left hepatic ducts, which are predominantly intrahepatic, and, in turn, joins the cystic duct to form the common bile duct.Spermatocele: A cystic dilation of the EPIDIDYMIS, usually in the head portion (caput epididymis). The cyst fluid contains dead SPERMATOZOA and can be easily differentiated from TESTICULAR HYDROCELE and other testicular lesions.Endocrine Gland Neoplasms: Tumors or cancer of the ENDOCRINE GLANDS.Ovarian Neoplasms: Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.Aspermia: A condition characterized by the complete absence of SEMEN. This disorder should be differentiated from AZOOSPERMIA, absence of sperm in the semen.Pseudomyxoma Peritonei: A condition characterized by poorly-circumscribed gelatinous masses filled with malignant mucin-secreting cells. Forty-five percent of pseudomyxomas arise from the ovary, usually in a mucinous cystadenocarcinoma (CYSTADENOCARCINOMA, MUCINOUS), which has prognostic significance. Pseudomyxoma peritonei must be differentiated from mucinous spillage into the peritoneum by a benign mucocele of the appendix. (Segen, Dictionary of Modern Medicine, 1992)Salivary Gland Neoplasms: Tumors or cancer of the SALIVARY GLANDS.Pancreatic Cyst: A true cyst of the PANCREAS, distinguished from the much more common PANCREATIC PSEUDOCYST by possessing a lining of mucous EPITHELIUM. Pancreatic cysts are categorized as congenital, retention, neoplastic, parasitic, enterogenous, or dermoid. Congenital cysts occur more frequently as solitary cysts but may be multiple. Retention cysts are gross enlargements of PANCREATIC DUCTS secondary to ductal obstruction. (From Bockus Gastroenterology, 4th ed, p4145)Urologic Surgical Procedures, Male: Surgery performed on the male genitalia.Neoplasms, Multiple Primary: Two or more abnormal growths of tissue occurring simultaneously and presumed to be of separate origin. The neoplasms may be histologically the same or different, and may be found in the same or different sites.Retroperitoneal NeoplasmsSalivary Glands, Minor: Accessory salivary glands located in the lip, cheek, tongue, floor of mouth, palate and intramaxillary.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Pancreatic Pseudocyst: Cyst-like space not lined by EPITHELIUM and contained within the PANCREAS. Pancreatic pseudocysts account for most of the cystic collections in the pancreas and are often associated with chronic PANCREATITIS.Ovarian Cysts: General term for CYSTS and cystic diseases of the OVARY.Cholangiopancreatography, Magnetic Resonance: Non-invasive diagnostic technique for visualizing the PANCREATIC DUCTS and BILE DUCTS without the use of injected CONTRAST MEDIA or x-ray. MRI scans provide excellent sensitivity for duct dilatation, biliary stricture, and intraductal abnormalities.Pancreatic Diseases: Pathological processes of the PANCREAS.Bile Ducts, Extrahepatic: Passages external to the liver for the conveyance of bile. These include the COMMON BILE DUCT and the common hepatic duct (HEPATIC DUCT, COMMON).Appendectomy: Surgical removal of the vermiform appendix. (Dorland, 28th ed)Pancreatectomy: Surgical removal of the pancreas. (Dorland, 28th ed)Cystadenocarcinoma, Serous: A malignant cystic or semicystic neoplasm. It often occurs in the ovary and usually bilaterally. The external surface is usually covered with papillary excrescences. Microscopically, the papillary patterns are predominantly epithelial overgrowths with differentiated and undifferentiated papillary serous cystadenocarcinoma cells. Psammoma bodies may be present. The tumor generally adheres to surrounding structures and produces ascites. (From Hughes, Obstetric-Gynecologic Terminology, 1972, p185)Adenocarcinoma, Mucinous: An adenocarcinoma producing mucin in significant amounts. (From Dorland, 27th ed)