A few months ago, keepers noticed a slow growing skin mass near Michael the Bornean orangutan’s arm pit or axilla. He was anesthetized for further evaluation, and the mass was surgically removed on June 12 for pathological evaluation.
After consulting with pathology specialists in primate and human pathology, we diagnosed the mass as apocrine carcinoma near his right armpit. This is a very rare type of cancer in people and can be locally invasive and aggressive in nature. This is the first time it has ever been seen in an orangutan.
On August 14, Michael was again anesthetized and underwent a second surgical procedure to further resect the tumor site with the goal to get tumor free surgical margins. The Zoo’s veterinary team, alongside an outside surgeon, Dr. Jeffrey Steurer, D.V.M.,M.S., D.A.C.V.S.(veterinary surgeon from Southwest Veterinary Surgical Service), surgically resected the area of the tumor as residual tumor appeared to be invading deeper into the tissue at the biopsy site. Tracer dye was injected to help identify sentinel lymph nodes in the area, which were also removed for evaluation of possible metastasis.
We are now waiting on pathology to determine the next steps for Michael, and we will keep you updated on his prognosis.
