Association of canine splenic hemangiosarcomas and hematomas with nodular lymphoid hyperplasia or siderotic nodules.

Hemorrhagic splenic masses diagnosed as hemangioma or hemangiosarcoma were reviewed. Lymphoid hyperplasia was present in none of the hemangiosarcoma cases and in 27% of the hematoma cases. Siderotic nodules in the capsule or trabeculae were present in 25% of hemangiosarcoma cases and in 36% of hematoma cases. Hemoabdomen was noted in the clinical history of 54% of hemangiosarcoma cases and in 22% of hematoma cases. The average age (10.3 and 9.6 years, respectively), sex ratios (slightly more males), and most common breeds (Labrador Retriever, Golden Retriever, and German Shepherd Dog) were similar for the hemangiosarcoma and hematoma cases. Since lymphoid hyperplasia is much more common in cases of hematoma, the presence of this feature lends support to a diagnosis of hematoma rather than hemangiosarcoma. Signalment, history of hemoabdomen, and presence of siderotic nodules do not point to one diagnosis over the other.