The left testicle is the size of a goose egg may be caused by acute orchitis, epididymitis, syringomyelia and so on. 1. Acute orchitis: testicular swelling, testicular pain or heaviness may occur, which may be accompanied by fever and other symptoms. 2. Acute epididymitis: when the infection is extensive and involves the testicle, the left testicle may be the size of a goose egg. 3. Syringomyelia: when taking bath or physical examination, the scrotum is found to be enlarged by chance, and a mass inside the scrotum may be felt, which may be manifested as the size of a goose egg at the left testicle. It is recommended that the left side of the testicle has the size of a goose egg in time to go to the hospital, clear causes, under the guidance of the doctor for standardized treatment, so as to avoid delays in the condition of the body to bring adverse effects.