顔面隆起性皮膚線維肉腫の切除縁と治療

Surgical Treatment for Facial Dermatofibrosarcoma Protuberans (DFSP)

はじめに

　隆起性皮膚線維肉腫（dermatofibrosarcoma protuberans：以下，DFSP）は比較的まれな軟部肉腫の1つであり，転移することはほとんどないが再発率は非常に高い 1）。好発部位である体幹部，四肢の切除においては水平方向に2～4 cmマージン，深部は筋膜を含めた切除が推奨されている 2）。

　一方，顔面はその構造から，“水平方向に2～4 cmマージン，深部は筋膜を含めた切除”が当てはまらない特殊部位といえる。

　今回，われわれが経験した，深部に浸潤を認めた顔面DFSPの経験をもとに顔面DFSPの切除縁と治療について考察したい。

　Dermatofibrosarcoma protuberans (DFSP) is a relatively rare soft-tissue sarcomas that often arises from the deep layers of the skin, and DFSP can infiltrate fat, muscle, and even bone. The most common site of DFSP is the trunk, followed by the extremities. The removal of a 2- to 4-cm margin horizontally around a DFSP lesion including fascia in the deep area is recommended. In the trunk and limbs, unlike the face, the muscles are encased in fascia and can move under the fascia; the thick fascia is considered an anatomical barrier. In contrast, facial muscles, which are mimic muscles, are cutaneous muscles that originate from the bones, muscles, and so on, and they stop directly at the skin; they do not have fascia. In addition, there are more than 20 muscles on each side of the face, and their running creates complex facial expressions when layers of muscles interact. The face also includes the eyes, nose, and mouth as sensory organs, and it combines appearance and function. We thus suggest that “a 2- to 4-cm margin in the horizontal direction, resection including fascia in the deep part” does not apply to the excision of DFSP at a facial site. However, since DFSP is a sarcoma with a high rate of recurrence, it is undeniable that a definite radical resection is necessary even for facial DFSP. Moreover, DFSP tends to occur in relatively young people, and the prognosis is relatively good without distant metastases to other organs. In other words, the treatment of facial soft-tissue sarcomas, including facial DFSP, is an area for which the oncoplastic surgery concept should be fully demonstrated.