Unilateral testicular enlargement in a teenager with Beckwith-Wiedemann syndrome: a case report

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is a rare congenital overgrowth disorder. A major feature is lateralized overgrowth, which can variably involve a single body district up to the entire hemisome. Visceral asymmetrical involvement has been observed, commonly represented by enlargement of one kidney or adrenal gland, rather than one gonad. CASE PRESENTATION: We report the case of a pubertal boy affected by BWS, who developed a progressive testicular enlargement, ipsilateral to the pre-existing external body overgrowth. Asymptomatic unilateral testis enlargement started after regular pubertal onset and worsened over time, without any associated pathological findings in a long-term follow-up. Since biopsy is not indicated in case of benign macro-orchidism, we hypothesize that this asymmetric enlargement could be an expression of visceral lateralized overgrowth in BWS. CONCLUSIONS: At the best of our knowledge, this is the first detailed report of unilateral testicular overgrowth in BWS. We revised common causes of painless unilateral scrotal masses in the pediatric age. Considering both the overall frequency of neoplasia and the malignancies predisposition in BWS, a testicular cancer should be carefully ruled out through a close follow-up, before stating a benign condition. A normal ultrasound pattern, together with normal serum hormonal levels and negative tumor markers, make testicular neoplasms highly unlikely.