a lack of apoptosis between the structures. Siblings documented to have splenogonadal fusion and an accessory spleen provides additional evidence of a possible genetic component. Associated Conditions Additional congenital abnormalities are most often found associated with the continuous type of splenogonadal fusion. These abnormalities include micrognathia, macroglossia, anal atresia, and pulmonary hypoplasia. The most commonly associated malformation is cryptorchidism. When limb abnormalities occur, Splenogonadal Fusion with Limb Defects is made as a separate diagnosis. Splenogonadal Fusion with Limb Defects is also of unknown cause but some literature suggests that the condition may be related to Hanhart syndrome and facial femoral syndrome. Splenogonadal fusion has also been identified in infants with Möbius syndrome and Poland syndrome. Diagnosis Diagnosis can be challenging pre-operatively, as patients are commonly asymptomatic. Physical examination can aid in diagnosis if the mass is palpated, but further confirmatory tests are necessary. Females are reportedly less affected by splenogonadal fusion, though it is possible that the condition is underdiagnosed due to the difficulty of internal gonad examination in females. On scrotal ultrasound, ectopic splenic tissue may appear as an encapsulated homogeneous extratesticular mass, isoechoic with the normal testis. Subtle hypoechoic nodules may be present in the mass. Limitations of doppler ultrasonography include visualizing the nonspecific paratesticular masses which can mimic malignancies such as rhabdomyosarcoma or embryonal sarcoma. Technetium-99m sulfur colloid scan is sensitive to target the liver, spleen, and bone marrow, therefore the scans can be used to identify ectopic splenic tissue when clinical suspicion is high. When technetium-99m sulfur colloid scans are not included in a patient's diagnostic workup, the diagnosis is often not made until the surgeon performs an abdominal exploration using laparoscopy which can visualize the splenic tissue grossly. Evaluation by biopsy including frozen section procedure is confirmatory for splenogonadal fusion. Histological examination will show normal splenic tissue which is made up of red and white pulp. Many people with splenogonadal fusion go undiagnosed without complication during their lifetime. Many cases have been diagnosed at autopsy or incidentally after orchiectomy. Treatment Treatment remains controversial given the benign nature of splenogonadal fusion. Splenogonadal fusion does not have known clinical manifestations that require intervention. Clinical observation is considered when the mass is diagnosed pre-operatively. Surgery is often required to confirm the diagnosis and exclude a mimic of a malignant mass. Surgical approach should attempt to divide the mass and the gonad at the connecting plane for removal of