Think Splenic Masses Mean Cancer? This Study Reveals Surprising Insights About Dogs and Hemangiosarcoma

Splenectomy is a common surgical procedure in dogs for addressing splenic masses, but the underlying causes of these masses can vary widely. A recent study reviewed 182 cases of splenectomy at a surgical specialty clinic from 2017 to 2021, shedding light on the prevalence and risk factors of splenic malignancy, particularly hemangiosarcoma (HSA), in dogs. The findings challenge some common assumptions about splenic masses and provide critical insights for veterinarians and dog owners alike.

Key Findings

1. Most Splenic Masses Are Benign
   Contrary to the belief that splenic masses often indicate malignancy, the study found that 57.7% of cases were benign, with no evidence of malignancy. This highlights the importance of histopathologic evaluation to confirm the diagnosis, as outward appearances can be deceiving.

2. Hemangiosarcoma Was Diagnosed in One-Third of Cases
   Of the 182 dogs studied, 32.4% were diagnosed with hemangiosarcoma (HSA), a highly aggressive cancer that arises from blood vessel linings. The presence of HSA was strongly associated with specific clinical findings, which could help predict its likelihood pre-surgery.

3. Key Risk Factors for Hemangiosarcoma
   The study identified several factors that increase the risk of HSA:

   • Thrombocytopenia (low platelet count)

   • Anemia

   • Smaller diameter of the largest splenic nodule

   • Hemoperitoneum (blood in the abdominal cavity), which was found in 91 dogs, 60.4% of whom had malignant lesions.

4. Incidental Splenic Lesions Are Rarely Malignant
   For dogs undergoing splenectomy due to incidentally identified splenic lesions (e.g., found during diagnostic imaging for unrelated issues), 93.9% of these cases were benign. This emphasizes that incidental findings are often not a cause for alarm.

5. Breed Insights: German Shepherds at Higher Risk
   While breed size was not generally predictive of malignancy, all six German Shepherds included in the study were diagnosed with HSA. This aligns with existing literature suggesting that German Shepherds may have a predisposition to this aggressive cancer.

Implications for Veterinary Practice

The study suggests that the prevalence of splenic malignancy, including HSA, may be overestimated in certain populations. Veterinarians should consider the presence of thrombocytopenia, anemia, smaller nodule size, and hemoperitoneum as indicators of higher malignancy risk. For incidental splenic lesions, the high likelihood of benign diagnoses can guide a more conservative approach to treatment.

Takeaway

This research underscores the importance of thorough diagnostic evaluation before assuming the worst about splenic masses. While hemangiosarcoma is a serious and aggressive condition, the majority of splenic masses are benign, particularly if identified incidentally.

Read full article here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0314737