malignant melanoma in situの2例

・悪性黒色腫の早期病変は異型メラノサイトの分布がtumor thickness 1 mm未満のものを指し，そのうち表皮内に限局するものはmelanoma in situである．手術摘出のみで予後良好である．

・自験例は小型の黒色斑であったが，ダーモスコピー所見によって悪性を疑い，病理組織学的所見と合わせてmelanoma in situと診断した．

・視診では境界明瞭，左右対称で色素性母斑を疑う場合でも，ダーモスコピーでparallel ridge patternなどの所見が明らかになり，ダーモスコピーは早期診断に有用である．

（「症例のポイント」より）

　

Two cases of malignant melanoma in situ

　

Ohara, Marina1）Mori, Tomoka1）Hioki, Tomoyuki1）Kamiya, Hideki1）Kitajima, Yasuo2） 1）Division of Dermatology, Kizawa Memorial Hospital 2）Kizawa Memorial Hospital

　

We report two cases of malignant melanoma in situ which were noticed in the early stage. Case 1 was a 23-year-old woman who noticed a black plaque on her big toe one year prior to presentation. Case 2 was a 40-year-old woman who noticed a small black plaque on her upper arm one year prior to presentation. We diagnosed their conditions malignant melanoma in situ. The staging was early enough for both patients to be treated with surgical excision alone. In both cases we excised the lesions with a 5mm margin of safety.