Visceral mast cell tumors in dogs: 10 cases (1982-1997).
OBJECTIVE
To characterize the clinical features of visceral mast cell tumors (MCT) without associated cutaneous involvement in dogs.


METHODS
Retrospective study.


METHODS
10 dogs with histologically confirmed MCT without associated cutaneous lesions.


METHODS
Information on signalment, clinical signs, laboratory examinations, and time from first admission to death was obtained from the medical record of each dog.


RESULTS
Purebred male dogs of miniature breeds appeared to have a higher prevalence of visceral MCT. Clinical signs included anorexia, lethargy, vomiting, and diarrhea. Anemia (n = 7), hypoproteinemia (5), and mastocythemia (5) were detected. Treatments, including glucocorticoids, were not successful. Primary sites of tumors were the gastrointestinal tract (n = 6) and the spleen or liver (1); the primary site was not confirmed in the remaining 3 dogs. In 7 dogs, tumors were categorized as grade II or III, on the basis of histologic findings. The prognoses were poor, and all dogs died within 2 months after first admission.


CONCLUSIONS
Visceral MCT is uncommon in dogs, and the prognosis is extremely poor. Biological behavior and drug susceptibility of visceral MCT may be different from cutaneous MCT. The lack of specific clinical signs may result in delay of a definitive diagnosis. The rapid progression of clinical signs and difficulty in diagnosis contributes to a short survival time.
Takahashi
T
T
Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan.
Kadosawa
T
T
Nagase
M
M
Matsunaga
S
S
Mochizuki
M
M
Nishimura
R
R
Sasaki
N
N
D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D001774:Blood Chemical Analysis / Q000662:veterinary; D001947:Breeding; D004283:Dog Diseases / Q000097:blood / Q000453:epidemiology / Q000473:pathology; D004285:Dogs; D005260:Female; D007414:Intestinal Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D008113:Liver Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D008297:Male; D012515:Mast-Cell Sarcoma / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D011379:Prognosis; D012189:Retrospective Studies; D013160:Splenic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*