Patient with Fanconi syndrome and confirmed carcinoma in situ in the right tongue margin area. However, no invasive component of the carcinoma was detected. Therefore, again before planned removal of the change on the edge of the tongue on the right and the floor of the mouth on the right, panendoscopy and sample biopsies, in particular from the edge of the tongue on the right, to definitively confirm the diagnosis or exclude an invasive carcinoma.