A mother brought her several-month-old baby to the doctor with tears in her eyes. The baby had a cyst in one testicle (ultrasound confirmed that it was not a syringomyelia outside the testicle). Some doctors advocated removing the testicle. My personal recommendation is that the first step is just to remove the cyst and do pathology labs. Here are the literature references and the logic of my recommendation. I looked at the ultrasound and there is a small cyst within a three centimeter cyst. What is its nature and can ultrasound separate the nature of the cysts? The more common causes of testicular cysts in infants and children are teratomas and epithelioid cysts. Other rare ones include dermatomal cysts, lymphadenomas, testicular cysts, testicular cystadenoma and testicular tumors (most of the latter have some solid tumor component). A comparative study of ultrasound epithelioid cysts, benign and immature teratomas published a few months ago (J Ultrasound Med. 2015 Oct;34(10):1745-51.) found that. Overall, more than 80% of the 19 testicular cysts were benign (6 epidermoid cysts and 10 mature teratoma) and more than 10% were neutral immature teratomas (3, immature teratoma, with some malignant potential). Immature teratoma is characterized by the young age of the child (mostly under eight months), elevated methemoglobin (23ng/mL or more), and a tumor length of 2.5 centimeters or more. The presence or absence of a solid tumor component on ultrasound cannot predict the nature of the teratoma. 100% confirmation of the diagnosis still depends on pathological sections after biopsy. If every child has an orchiectomy, then part of it will be wrongly cut. A missing testicle is a big psychological blow to both the parents and the child. So, personally, I would do only cystectomy and keep the testicle if the meconium is normal. If the pathology report reveals an immature or malignant teratoma, most of the patients’ parents will accept a second orchiectomy.