Objective–To describe the clinical features, surgical
and histologic findings, biological behavior, and outcome
of dogs with retroperitoneal sarcomas.
Procedures–Medical and pathology records from 1992
to 2002 of dogs with tumors originating in the retroperitoneal
space were reviewed. Dogs with retroperitoneal
tumors originating from the adrenal glands, kidneys, or
ureters were excluded. Inclusion criteria included observation
of a tumor arising from the retroperitoneal space
during exploratory surgery or necropsy and histologic
confirmation of tumor type. Details of clinical signs, diagnostic
findings, surgical management, and outcome
were determined from medical records and telephone
interviews with veterinarians and owners.
Results–Retroperitoneal sarcoma was diagnosed in
14 dogs, 2 at necropsy and 12 during exploratory
surgery. Hemangiosarcoma was the most common
histologic diagnosis. Seven dogs had regional extension
of the sarcoma into adjacent organs, and 4 dogs
had metastatic disease. Grossly complete resection
was possible in 6 dogs. Cytoreductive surgery or incisional
biopsy was performed in the remaining dogs.
Two dogs were treated with palliative radiation therapy
(1 intraoperatively and 1 postoperatively). Three
dogs received adjunctive chemotherapy, although
none completed the targeted course because of
development of local recurrence or metastatic disease.
Local recurrence was reported in 2 of 12 dogs
and metastasis in 10 of 14 dogs. Thirteen dogs died or
were euthanatized as a result of the retroperitoneal
sarcoma; 1 dog was alive and disease-free 410 days
after surgery. Median survival time was 37.5 days.
Conclusions and Clinical Relevance–In dogs,
retroperitoneal sarcomas are aggressive tumors with
a high rate of local recurrence and metastasis, and a
poor survival time. (J Am Vet Med Assoc 2004;224:
Objective—To evaluate prognostic factors associated with outcome of dogs with multiple cutaneous mast cell tumors (MCTs) treated with surgery with or without adjuvant treatment.
Design—Retrospective case series.
Animals—54 dogs with a minimum of 2 simultaneous, histologically confirmed cutaneous MCTs that had been excised and had adequate staging and follow-up data.
Procedure—Medical records from 1998 to 2004 were examined. Outcome was assessed with the Kaplan-Meier product-limit method and log-rank analysis. Prognostic factors evaluated included signalment; number, histologic grade, location, size, local recurrence, and de novo development of MCTs; quality of surgical margins; clinical signs at the time of diagnosis; and use of adjuvant treatment.
Results—Medical records of 54 dogs with 153 tumors were included. Median follow-up time was 658 days. Median disease-free interval (1,917 days; range, 11 to 1,917 days) and median survival time (1,917 days; range, 14 to 1,917 days) were not yet reached. The 1- year and 2- to 5-year survival rates were 87% and 85%, respectively. The overall rate of metastasis was 15%. Factors that negatively influenced survival time in the univariate analysis included incomplete excision, local recurrence, size > 3 cm, clinical signs at the time of diagnosis, and use of adjuvant treatment. Presence of clinical signs at the time of diagnosis was the only negative prognostic factor for disease-free interval detected in the multivariate analysis.
Conclusions and Clinical Relevance—Results suggested that multiple cutaneous MCTs in dogs are associated with a low rate of metastasis and a good prognosis for long-term survival with adequate excision of all MCTs.