INTERSTITIAL CELL TUMOR IN A BLACK-AND-WHITE RUFFED LEMUR (VARECIA VARIEGATUS VARIEGATUS)

A 14.5-year-old male black-and-white ruffed lemur exhibited acute testicular enlargement, poor pelage quality, and increased aggression, leading to the diagnosis of an interstitial cell tumor in the left testicle. A unilateral orchiectomy was performed, and microscopic evaluation confirmed the tumor without signs of malignancy. Post-surgery, the lemur's coat quality improved significantly, and its behavior shifted from aggressive to submissive, eventually normalizing over several months. Follow-up examinations showed no metastasis or neoplasia in the remaining testicle, and hormone levels were normal. At 19 months post-surgery, the lemur's coat was nearly normal, and it maintained its social status without abnormal aggression.