With support of the Old World Monkey TAG and the Francois’ langur (Trachypithecus francoisi) studbook, a review of the current and historic captive AZA population was undertaken. During evaluation of a separate disease process in a targeted population (n=158), five cases of naso-oral squamous cell carcinoma (SCC) were identified. Initial epidemiologic analysis of these cases uncovered a familial relationship. Further assessment of records for directly related animals (n=59) identified six additional SCC cases.1 Median age of death of affected animals (seven males, four females) was 15.6 years. Clinically, affected animals were reported with weight loss, difficulty eating, missing or loose teeth noted during examination, and chronic nasal or ocular discharge. At presentation, affected animals were found with masses or ulcerated swellings of the maxillary gingiva, nasal sinuses, tongue, or oropharynx. Affected animals also were reported with a range of associated oral conditions, including abscesses, glossitis, stomatitis, and mucosal disruptions. Surgical debridement was attempted in four cases, but local recurrence was a common sequela, leading to deteriorating clinical condition necessitating euthanasia. Median survival time from onset of clinical signs was five months. Histologic findings included local invasion of anaplastic epithelial cells and peripheral nests of basaloid cells with necrosis. Although a solitary case of oral SCC has been reported in this species from a population separate from this evaluation, this case series suggests a familial predilection for SCC in this species.2 Close monitoring of living animals is recommended, especially for individuals related to identified cases.
1. Gibson D, E Chu. Management and behaviour of François’ langur Presbytis francoisi francoisi at the Zoological Society of San Diego. Int. Zoo Yearb. 1992;31:184–191.
2. Ueda M, H Somura, K Matsui, R Matsumoto, Y Yamamoto, K Tamai. 2007. A multicentric squamous cell carcinoma of the oral cavity in a Francois’ leaf monkey (Trachypithecus francoisi francoisi). Jpn J Zoo Wildl Med. 2007;12:117–121.