A splenic mass may be an incidental finding during a physical exam, abdominal ultrasound or laparotomy of a dog. Symptoms may be absent or non-specific, such as inappetence, vomiting or weight loss.
What should you do in such a case?
Ignore the mass or remove the spleen?
It is important to guide clients with reliable statistics so they can make an informed decision.
A retrospective case study* was conducted to determine the rate of malignancy and survival rates in 105 dogs that underwent splenectomy for incidental, non-ruptured, splenic masses. Patients were identified over 4 years from the medical records of the Angell Animal Medical Center (Boston, MA). Only dogs with histologically confirmed diagnoses were included in the study.
Here are the main results of the study:
- 70% had benign splenic lesions and 30% had malignant tumors.
- 58% of the dogs with malignant neoplasia had hemangiosarcoma.
- The median life expectancy of dogs with benign lesions was 436 days (< 15 months).
- The median survival of dogs with malignant lesions was 110 days (< 4 months).
- The average life expectancy of dogs with hemangiosarcoma was 132 days (> 4 months). Those who had follow-up chemo had a median survival of 223 days (> 7 months).
Dogs who undergo splenectomy for an incidental splenic mass (without hemoabdomen) have a better long-term prognosis than dogs who are symptomatic.
Patients with benign masses tended to have higher preop PCVs (median of 42%) than patients with malignant nodules (37%). In addition, a higher preop PCV leads to a better outcome.
Among the 95 dogs who underwent preop abdominal ultrasonography, 41% of malignant tumors were hypoechoic, which was significantly more frequent than benign masses (22%).
The overall median diameter of splenic masses was 7 cm. Benign masses were slightly smaller (median 6.25 cm) than malignant tumors (median 8 cm).
While splenic nodules were more commonly benign in this study, they can still grow and rupture, causing hemoabdomen. This can increase complications and worsen survival rates. Therefore, early intervention is recommended for any focal lesion in the spleen in order to limit the development of metastasis and increase life expectancy. In addition, chemotherapy should be considered for malignant splenic lesions.
The most important finding of this study about is: 30% lesions were malignant and 70% were benign.
* MJ Cleveland et al. “Incidence of Malignancy and Outcomes for Dogs Undergoing Splenectomy for Incidentally Detected Non-Ruptured Splenic Nodules or Masses: 105 cases (2009–2013).” JAVMA 2016, Vol 248, No. 11, p 1267-1273.