Prevalence, number and morphological types of multinucleated histiocytic giant cells in equine inflammatory dermatoses: a retrospective light microscopic study of skin-biopsy specimens from 362 horses.
BACKGROUND
Multinucleated histiocytic giant cells (MHGC) are seen frequently in skin-biopsy specimens from horses with inflammatory dermatoses. However, the prevalence, number and morphological types of these cells have not been reported.


OBJECTIVE
To determine the prevalence, number and morphological types of MHGC in equine inflammatory dermatoses, and the association of these cells with specific conditions.


METHODS
Skin-biopsy specimens from 335 horses with inflammatory dermatoses and from 27 horses with normal skin were evaluated for the prevalence, number and morphological types of MHGC.


RESULTS
The prevalence and number of MHGC were greater in granulomatous dermatoses than in nongranulomatous dermatoses. Infectious and noninfectious dermatoses were not different in terms of prevalence or morphological types of MHGC. Foreign-body MHGC were the predominant type in almost all cases. MHGC were not seen in normal skin.


CONCLUSIONS
MHGC are seen in a wide variety of equine inflammatory dermatoses, especially those that are granulomatous. Number and morphological types of MHGC are of no apparent diagnostic significance.


CONCLUSIONS
MHGC are frequently present in a wide variety of inflammatory dermatoses in the horse. Because the prevalence, number and morphological types of MHGC are of minimal diagnostic significance, special stains and tissue cultures are necessary to confirm specific diagnoses.
Cohen
R D
RD
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Scott
D W
DW
Erb
H N
HN
D000818:Animals; D001706:Biopsy / Q000662:veterinary; D015726:Giant Cells / Q000166:cytology*; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D007249:Inflammation / Q000473:pathology / Q000662:veterinary*; D008853:Microscopy / Q000662:veterinary*; D012189:Retrospective Studies; D012867:Skin / Q000166:cytology* / Q000473:pathology; D012871:Skin Diseases / Q000145:classification / Q000473:pathology / Q000662:veterinary*