Pigmented epithelioid melanocytoma: report of first Japanese cases previously diagnosed as cellular blue nevus.
BACKGROUND
The term 'pigmented epithelioid melanocytoma (PEM)' was recently used for borderline melanocytic tumor/low-grade melanoma including cases previously diagnosed as human animal-type melanoma and epithelioid blue nevus. No Japanese cases have been reported.


METHODS
We reviewed 219 cases previously diagnosed as blue nevus in Japan. Common blue nevus was identified in 154 cases and cellular blue nevus in 65 cases.


RESULTS
We have found two Japanese cases of PEM previously diagnosed as cellular blue nevus. Two patients were female. The age at presentation was 32 and 28 years. Two lesions were on the buttock. Two cases fulfilled histological criteria proposed for PEM. There is no evidence of recurrence or metastases.


CONCLUSIONS
PEM is a distinct melanocytic tumor and the unifying diagnostic term. PEM is present in Japanese, but these cases may be previously diagnosed as cellular blue nevus. Japanese pathologists should recognize a new concept of PEM, and when they make a diagnosis of PEM, they should be recommended sentinel lymph node sampling.
Ito
Keigo
K
Department of Dermatology, The Jikei University School of Medicine, Tokyo, Japan. keigo@jikei.ac.jp
Mihm
Martin C
MC
D000328:Adult; D044466:Asian People; D005260:Female; D006801:Humans; D008545:Melanoma / Q000473:pathology*; D018329:Nevus, Blue / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*