頸椎および椎体外に発生した赤芽球性肉腫の1例

A case of erythroblastic sarcoma arising in the cervical spine and extravertebral body

骨髄性肉腫（myeloid sarcoma：MS）は，WHO分類では「骨髄芽球ないし未熟骨髄細胞から構成され，髄外に腫瘤を形成する骨髄増殖性疾患」と定義される^1）2）。本疾患は高率に急性骨髄性白血病に移行するため，早期診断および早期治療が必要とされる予後不良の疾患である^1）3）。今回我々は，頸椎と硬膜外および右鎖骨上窩に発生した，骨髄性肉腫の亜型である赤芽球性肉腫の1例を経験したので報告する。

The case is a 65-year-old man. In August 2022, he was aware of numbness and weakness in his right upper extremity and right hand and visited a nearby doctor. He was referred to the orthopedic department of our hospital for suspicion of cervical spondylotic radiculopathy. CT and MRI showed a mass lesion in the sixth cervical vertebra, from the right intervertebral foramen to the spinal canal and right supraclavicular fossa. The postoperative histopathological diagnosis was erythroblastic sarcoma. Erythroblastic sarcoma is a subtype of myeloid sarcoma, a disease with a poor prognosis that progresses to acute myeloid leukemia（AML）, and early diagnosis is important.