耳下腺に発生したIgM-λ型髄外形質細胞腫の1例

IgM-Lambda Producing Extramedullary Plasmacytoma of the Parotid Gland: Report of a Case

I．緒言

　髄外形質細胞腫は骨髄以外に原発する形質細胞腫であり比較的まれな疾患である。その多くは上気道に発生し，血清蛋白や尿蛋白に異常をきたすことは少ないとされている。

　今回われわれは単クローン性免疫グロブリン血症を伴う耳下腺原発の髄外形質細胞腫を経験し，酵素抗体法（PAP法）にて腫瘍細胞よりIgM-λ型免疫グロブリンが産生されていることが確認できたので，若干の文献的考察を加えて報告する。

　A 75-year-old female with plasmacytoma of the parotid gland was reported.

　A narrow spike was found in serum protein electrophoresis, and IgM-Lambda was detected by immunoelectrophoresis. Cytoplasmic IgM-Lambda determinants were demonstrated immunohistochemically.

　The tumor was well controlled by surgery and irradiation, and IgM level in the serum was decreased. But IgM level was increased 2 months later, and chemotherapy was administered.

　There was no local recurrence and no evidence of multiple myeloma after the chemotherapy. The patient is now under clinical observation.