Premium
Multicentric mast cell tumors in a horse
Author(s) -
Millward Laurie M.,
Hamberg Alex,
Mathews Jennifer,
MachadoParrula Cecilia,
Premanandan Christopher,
Hurcombe Samuel D. A.,
Radin M. Judith,
Wellman Maxey L.
Publication year - 2010
Publication title -
veterinary clinical pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 51
eISSN - 1939-165X
pISSN - 0275-6382
DOI - 10.1111/j.1939-165x.2010.00229.x
Subject(s) - pathology , eosinophilic , cd117 , horse , staining , toluidine , medicine , mast cell , eosinophilic granuloma , infiltration (hvac) , cytology , biology , cd34 , chemistry , immunology , genetics , thermodynamics , paleontology , physics , stem cell
Abstract: A 6‐year‐old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine‐needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma. Histologic evaluation of surgical biopsies of lesions from both limbs was performed on sections stained with H&E, toluidine blue, and Luna stains. The histologic diagnosis was MCT, and staining with toluidine blue and Luna stains confirmed the presence of mast cells and eosinophils, respectively. In addition, the mast cells strongly expressed CD117. This is the first reported case of cutaneous mast cell neoplasia in a horse in which primary presenting complaints were draining tracts and distal limb subcutaneous edema involving multiple limbs. This case illustrates the utility of staining for CD117 expression in combination with traditional stains, such as toluidine blue and Luna, in differentiating MCTs from other eosinophilic lesions in horses.