Massive lymphangiosarcoma in a dog: a case report.

A 12-year-old neutered male Golden Retriever presented with a progressively enlarging mass in the submandibular region. Histopathological diagnosis confirmed lymphangiosarcoma with metastasis to the liver and spleen. The pleomorphic neoplastic endothelial cells of the tumor grow directly on bundles of dermal collagen, forming numerous clefts and interconnecting channels that are devoid of conspicuous hematic elements. As lymphangiosarcoma is an uncommon malignant neoplasm, the number of previously reported cases and information of the tumor is limited. The present report describes the clinical history and histopathological diagnosis of a progressive lymphangiosarcoma in the submandibular region with metastases in a dog. [ABSTRACT FROM AUTHOR]