Objective—To compare clinical outcome of dogs
with cutaneous mast cell tumors (MCTs) in the
inguinal or perineal region with outcome for dogs with
MCTs in other cutaneous locations.
Animals—37 dogs with MCTs in the inguinal or perineal
region and 87 dogs with MCTs in other cutaneous
Procedure—Information obtained from the medical
records included sex, breed, age, histologic grade of
all tumors, number and location of all tumors, tumor
size (ie, diameter of the tumor), completeness of surgical
excision, treatments administered in addition to
surgery, and outcome. In all dogs, the primary treatment
consisted of surgical excision.
Results—Disease-free interval and survival time for
dogs with MCTs in the inguinal or perineal region were
not significantly different from values for dogs with
MCTs in other cutaneous locations. Dogs with incompletely
excised tumors, dogs with grade III tumors, and
dogs that received systemic treatment were 2, 2.5,
and 4 times as likely, respectively, to have a relapse.
Factors significantly associated with a shorter survival
time were age > 8 years, metastatic disease at the
time of initial diagnosis, and tumor relapse.
Conclusions and Clinical Relevance—Results of the
present study suggest that dogs with MCTs in the
inguinal or perineal region do not have a worse prognosis
in regard to disease-free interval or survival time
than do dogs with MCTs in other cutaneous locations.
Treatment recommendations for dogs with cutaneous
MCTs should be based on confirmed predictors of biological
behavior, such as histologic grade and clinical
stage. (J Am Vet Med Assoc 2005;226:1368–1374)