Editorial Comment to Clear identification of the rare solitary external iliac lymph node metastasis of testicular cancer by using indocyanine green fluorescence guidance.

Enei et al. reported a solitary, left, external, iliac lymph node recurrence of testicular cancer. They identified the lymphatic drainage route via indocyanine green (ICG) fluorescence imaging and performed precise metastatic lymph node dissection. ICG imaging may greatly aid lymph node dissection in patients with testicular cancer, as is the case for patients with other types of cancer. ICG‐guided surgery has been reported for several types of cancer, including prostate cancer. , , However, no report has dealt with testicular cancer. This report is thus of interest and important. However, I think that several issues remain before ICG guidance can become routine during surgery to treat testicular cancer.

First, in general, ICG‐guided lymph node dissection in cancer patients is performed in the presence of the primary tumor. However, in the reported case, the patient had undergone high orchiectomy and thus lacked the primary cancer. In such a case, the site of ICG solution must be considered. Injection into the internal inguinal ring was one of the possible methods reported.

Second, intensive lymphangiographic research conducted between 1960 and the 1980s identified testicular lymphatic flow. However, the lymphatic drainage anatomy of the normal testis must be studied via ICG fluorescence imaging prior to ICG‐guided lymph node dissection for patients with testicular cancer. As a matter of course, this normal lymphatic flow analysis should be performed with a proper and careful ethical protocol.

Finally, as testicular cancer is often more aggressive than prostate cancer, we need to determine whether ICG‐guided lymph node removal would be effective in cases with bulky lymph node metastases after chemotherapy.

ICG‐guided lymph node dissection of testicular cancer would be very useful. This paper shows that this may be possible. Further studies are required to establish the procedure.

Conflict of interest

The author declares no conflict of interest.