正畠 千夏

Chinatsu SHOBATAKE

奈良県立医科大学附属病院皮膚科

Department of Dermatology, Nara Medical University

キーワード : epidermal cyst, calcifying epithelioma, lipoma, angiolipoma, nevus lipomatosus cutaneous superficialis

近年高周波プローブの普及に伴い，皮膚科領域でも超音波検査が広まりつつある．本稿では皮膚科領域の超音波入門として，表皮嚢腫（粉瘤）や石灰化上皮腫，脂肪腫，異物肉芽腫などの超音波所見の特徴を解説した．表皮嚢腫では通常のものと炎症性のもの，また外毛根鞘嚢腫や皮様嚢腫などの表皮嚢腫と鑑別を要する疾患との所見の違いを考察した．また石灰化上皮腫では石灰化の程度によって超音波像が変化する．さらに脂肪腫や血管脂肪腫，表在性皮膚脂肪腫性母斑など，脂肪細胞の増殖する疾患であっても超音波像が異なり診断に有用である．日常よく遭遇する良性皮下腫瘤について臨床所見，超音波検査所見，病理所見をあわせて提示した．

As high-frequency ultrasound transducers have become readily available in recent years, ultrasound imaging is being adopted widely in the field of dermatology. As an introduction to ultrasound imaging in the field of dermatology, I describe the characteristics of benign tumors, such as epidermal cysts (atheromas), calcifying epitheliomas, lipomas, and foreign body granulomas, on ultrasound. Specifically, I discuss characteristics that help distinguish inflammatory epidermal cysts from normal cysts, as well as trichilemmal cysts and dermoid cysts from epidermal cysts. Ultrasound imaging can also be used to characterize calcifying epitheliomas as the degree of calcification affects ultrasound images, and help diagnose conditions that involve proliferation of adipocytes, including lipomas, angiolipomas, and nevus lipomatosus cutaneous superficialis. I describe the clinical findings, ultrasound characteristics, and pathological findings of common benign subcutaneous tumors.