title: Cellular blue nevus with nevus cells in a sentinel lymph node.
abstract: Regional lymph node involvement by a cellular blue nevus has been reported. However, it has recently been suggested that specific cases with "benign metastasizing" cellular blue nevi are actually rare. This study describes a typical case of a cellular blue nevus with nevus cells in a sentinel lymph node. We demonstrated that a cellular blue nevus clearly involved the regional lymph node and investigated the immunohistochemical profiles of such nodal cellular blue nevus cells. The location of the nevus cells fundamentally indicated a benign type, with limitation to the capsule and the fibrous trabeculae. However, only a few, isolated nevus cells were also seen in the parenchyma of the lymph node. The nevus cells in the capsule and the fibrous trabeculae were positive for c-kit, like the migrating melanocytes from the neural crest. In cellular blue nevi or lesions with similar histopathological features, it may be appropriate to consider the predominant involvement of the capsule as well as the benign cytological features and the immunohistochemical profiles (Ki-67-, PCNA-, and c-kit+) of the nodal cells to be a benign sign.
authors.affiliation: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan. misago@post.saga-med.ac.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Misago
authors.forename: Kohtarou
authors.initials: K
authors.lastname: Nagase
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Shinoda
authors.forename: Shinich
authors.initials: S
authors.lastname: Koba
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Narisawa
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D018329:Nevus, Blue / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*