Introduction: In an attempt to standardise the technique and to improve the identification of lymphatics, intra-testicular injection of methylene blue or Isosulfan blue has been described in the literature. We report on a new but similar complication in two patients with this technique.Methods: For both patients, methylene blue 0.2 ml was injected into the testis intra-operatively on the side of the varicocoele. Transperitoneal laparoscopic isolation of spermatic vessels and division between Ligaclips sparing two lymphatic channels highlighted by the dye were performed. Follow-up and scans of the testes were performed between 4 and 6 months. Pre-operative ultrasound did not show any testicular lesion.Results: At follow-up, both patients were cured of their symptoms, had less-pronounced swelling and no hydrocoele. Post-operative scans in both showed a hypoechoic lesion in the ipsilateral testis. Tumour markers were normal, and MRI is awaited as per MDT discussion.Conclusion: A previously unreported finding has caused much patient, parental and clinical anxiety and uncertainty, further tests, and MDT discussions with no clarity in its implications for the future. We propose a more thorough review of all the other centres using this technique. Undoubtedly, these patients will need further follow-up to understand its true impact.