Papillomas in primates are similar to those occurring in other species and occur on any surface covered by stratified squamous epithelium.2 They may be solitary or multicentric, have potential for spontaneous regression, and occasionally can transform to squamous cell carcinoma.2 Many primate papillomas have been associated with various papillomaviruses.2 There is a single tumor study that lists a papilloma occurring in the skin of a ring-tailed lemur (Lemur catta), although the site of the lesion was not specified.1 This appears to be the first report of this condition in red roughed lemurs (Varecia variegata rubra).
A breeding pair of red-ruffed lemurs has produced three litters in 2002, 2003 and 2005. Offspring in 2002 were stillborn. The 2 offspring in 2003 were examined at 5 mo of age and both were found to have perineal lesions diagnosed histologically as papillomas, likely of viral etiology. A parent-reared, female born to these parents in 2005 was diagnosed with identical perineal papillomas at 8 mo of age and again at 10 mo of age. Lesions were examined during a regular scheduled preventive medicine examination and found to be isolated to the skin surrounding the perineum. Lesions were multifocal, round, raised, flat areas of pale discoloration of variable size. Lesions were not found on a male sibling. Routine hematology, rectal culture for enteric pathogen screen, thyroid panel, and intra-dermal tuberculin testing results were unremarkable. Lesions regressed to total resolution by 11 mo of age. Treatment has been non-specific with broad-spectrum antibiotic use and oral anti-inflammatory ointments to minimize any discomfort. Adult animals of this social group have not been found to exhibit skin lesions during routine physical examinations.
Histologically the papillomas were comprised of discreet foci of well differentiated but hyperplastic stratified squamous epithelium with a prominent granular layer supported by inflamed fibrovascular stroma and a mixed perivascular inflammatory cell infiltrate in the underlying dermis. Intracellular edema was prominent in epithelium of the granular layer, with occasional balloon degeneration and superficial erosion or crusts. No intracytoplasmic or intranuclear inclusions were seen. A viral etiology and possible familial disposition are suspected for this condition, and electron microscopic, immunohistochemical and molecular studies are in progress at the time of this writing.
The authors thank Jamie Kinion for data retrieval, Christie Buie for literature retrieval, and Histology Consulting Service for slide preparation.
1. Appleby EC. 1969. Tumours in captive wild animals: some observations and comparisons. 1969. Acta Zool. Pathol. Anteverpiensia. 48: 77–92.
2. Sundberg JP, ME Reichman. 1996. Papillomavirus Infections. In: Jones TC, U Mohr, RD Hunt, eds. Nonhuman Primates II. Springer-Verlag, New York. Pp. 1–8.