title: Regressed subungual melanoma simulating cellular blue nevus: managed with sentinel lymph node biopsy.
abstract: BACKGROUND
  Subungual melanoma, a not uncommon presentation of cutaneous melanoma in Asian populations, is easily overlooked as benign and thus is improperly treated.
  
  
  OBJECTIVE
  To present two cases with clinical suspicion of subungual melanoma. Skin biopsies failed to demonstrate the diagnostic features of malignancy.
  
  
  METHODS
  Lymphoscintigraphy and sentinel lymph node (SLN) biopsies were performed to determine regional lymph node status.
  
  
  RESULTS
  Both hematoxylin-eosin and HMB45 staining revealed melanoma cells in the SLN of the patient. The second patient's SLN was negative for malignant cells, but her excised primary lesion showed extensive regressed melanoma.
  
  
  CONCLUSIONS
  Regression phenomena are not uncommon for subungual melanoma. An extention biopsy techniques are useful for determining nodal basin status in regressed subungual melanoma.
authors: Department of Dermatology, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors: Chih-Hsun
authors: CH
authors: Yang
authors: Jiun-Ting
authors: JT
authors: Yeh
authors: Su-Chin
authors: SC
authors: Shen
authors: Yung-Feng
authors: YF
authors: Lo
authors: Tseng-tong
authors: TT
authors: Kuo
authors: John W C
authors: JW
authors: Chang