Presumed congenital lymphangioma in a dog: ultrasonographic and computed tomography findings, presentation and treatment

A one‐year‐old crossbreed dog was referred for investigation of a mass in the left hindlimb with an incisional biopsy consistent with lymphangioma. CT revealed a large homogeneous, well‐defined mass within the left caudal peritoneal cavity that extended through the vascular lacuna towards the left stifle joint. Ultrasound revealed poorly defined multilocular cystic mass with internal septa of mixed echogenicity and poor colour Doppler flow. Lymphangioma should be considered as differential diagnosis for masses with these imaging characteristics. CT was most helpful in establishing the extent of neoplastic invasion and margins of the mass.