Facial numbness restricted to the distribution of the mental nerve(mental neuropathy) is called "numb chin syndrome". The clinical importance of this syndrome is associated with first recognition of involvement of malignant diseases. The malignant neoplasm with numb chin syndrome show rapid progression and high mortality. We present a 43-year-old female who had been treated by radiotherapy for precursor T-cell leukemia/lymphoma involving the central nervous system( CNS) previously and later developed mental nerve invasion without central nervous system recurrence. MRI images revealed the CNS tumor mass remitted, and there was no identified peripheral nervous system(PNS) involvement including the mental nerve invasion, nevertheless the patient complained of consistent numbness and pain on right mandibular area. This is the first case of precursor T-cell leukemia/lymphoma accompanying mental nerve invasion without recurrence for central nervous system. Proper interpretation for mental neuropathy may lead to the prompt diagnosis and therapeutic intervention.

• 한선희(연세대학교 치과대학 구강병리학교실, 구강종양연구소) | Seon Hui Han
• 남정우(구강악안면외과학교실) | Jung Woo Nam
• 박혁(구강악안면방사학교실) | Hyok Park
• 김형준(구강악안면외과학교실) | Hyung Jun Kim
• 김남희(연세대학교 치과대학 구강병리학교실, 구강종양연구소) | Nam Hee Kim
• 김현실(연세대학교 치과대학 구강병리학교실, 구강종양연구소) | Hyun Sil Kim
• 육종인(연세대학교 치과대학 구강병리학교실, 구강종양연구소) | Jong In Yook correspondence