Spontaneous neoplasms observed in cynomolgus monkeys (Macaca fascicularis) during a 15-year period

A total of 33 tumors were observed during a time period of 15 years (1992-2006) in cynomolgus monkeys. The great majority of neoplasms was benign (23 benign neoplasms versus 10 malignant tumors). Fourteen appeared in males and 19 in females. The age of tumor-bearing animals ranged between 2 years 2 months and 13 years 9 months. Most of the tumors (22) in the cynomolgus monkeys were seen in endocrine organs (adrenal cortical adenoma, adrenal hemangioma, C-cell carcinoma, follicular adenoma), respiratory system (nasal cavity adenoma, pulmonary squamous cell carcinoma, bronchio-alveolar carcinoma, bronchiolar papilloma, chondromatous hamartoma) and female genital system (uterine polyp, uterine adenoma, uterine leiomyoma and teratoma of the ovary). Four animals revealed malignant lymphoma infiltrating multiple organs.