美馬 康幸¹, 長谷川 潤一¹, 古谷 菜摘¹, 佐々木 貴充¹, 倉崎 昭子¹, 土居 正知², 高木 正之², 小池 淳樹², 鈴木 直¹

Yasuyuki MIMA¹, Junnichi HASEGAWA¹, Natsumi FURUYA¹, Takamichi SASAKI¹, Akiko KURASAKI¹, Masatomo DOI², Masayuki TAKAGI², Junki KOIKE², Nao SUZUKI¹

¹聖マリアンナ医科大学産婦人科学, ²聖マリアンナ医科大学病理診断科

¹Department of Obstetrics and Gynecology, St Marianna University School of Medicine, ²Department of Pathology, St Marianna University School of Medicine

キーワード : placental hemangioma, placental insufficiency, fetal growth restriction, Doppler ultrasound

胎盤血管腫は組織学的にのみ確認されて，臨床的には問題のないものが少なくない一方，胎児発育不全や胎児貧血などの原因になることがある．自験例の報告と超音波検査による胎盤精査時のカラードプラの必要性について論じる．症例は妊娠31週に胎児発育不全のため当院紹介受診となった．母体既往，胎児，胎児付属物に明らかな異常はなかった．染色体検査は施行されていなかったが，明らかな原因を同定できない胎児発育不全と診断した．その後のBモード超音波検査で胎盤の一部が他の胎盤実質と比較して低輝度であることに気づき，カラードプラを施行したところ豊富な血流の増加を認め，胎盤血管腫と診断した．管理分娩の方針とし妊娠37週分娩誘発して児娩出に至った．児は2,162g，Apgar Score 1分値9点，5分値10点．児には貧血やdisseminated intravascular coagulation，心不全などの合併症は認められなかった．娩出胎盤には4×6 cm大のやや赤色の腫瘤を認めた．病理組織学的検討において腫瘤は血管腫であり血管腫周囲には小梗塞像も認められた．本症例の血管腫は小さくはなかったが，Bモードでは正常胎盤実質と区別がつきにくい画像所見であった．妊娠中の胎盤の評価やスクリーニングには，Bモードだけではなく，ルーチンでカラードプラも併用する必要があると考えられた．

Placental hemangiomas exist only histologically. While many are clinically harmless, they can cause fetal growth restriction and fetal anemia. We report our case and discuss the need for color Doppler during placental examinations with ultrasonography. The patient was referred to our hospital for fetal growth restriction at 31 weeks of gestation. There were no obvious abnormalities in the medical history, foetation, or fetal appendages. Chromosome tests had not been performed, but the diagnosis was fetal growth restriction for which no obvious cause could be identified. Subsequent B-mode ultrasonography revealed that part of the placenta was less bright than the other placental parenchyma, and color Doppler was performed. As a result, an abundant increase in blood flow was observed, and placental hemangioma was diagnosed. As a policy of controlled delivery, labor was induced and the baby was delivered at 37 weeks of gestation. The child weighed 2,162 g, with Apgar scores of 9 and 10 at 1 and 5 minutes, respectively. No complications such as anemia, disseminated intravascular coagulation, or heart failure were observed in the infant. A slightly red mass measuring 4×6 cm was found in the delivered placenta. Histological examination revealed that the mass was a hemangioma, and a small infarct image was also found around the hemangioma. The hemangioma in this case was not small, but the B-mode imaging findings were such that it was difficult to distinguish it from the normal placental parenchyma. Routine use of color Doppler as well as B-mode ultrasonography for placental evaluation and screening during pregnancy may be warranted.