日本新生児成育医学会雑誌　第30巻　第1号　67～72頁（2018年）

日本新生児成育医学会雑誌　30(1)：67-72；2018　

受付日：平成29．04．13

受理日：平成29．08．03

胎児期から退縮傾向を認めた新生児神経芽腫の1 例

Spontaneous Regression of Prenatally Diagnosed Neuroblastoma

姫路赤十字病院　小児科

Department of Pediatrics, Japanese Red Cross Society Himeji Hospital

芦名満理子・上村裕保・柄川　剛・五百蔵智明・久呉真章

Mariko ASHINA，Hiroyasu UEMURA，Tsuyoshi EGAWA，Tomoaki IOROI，Masaaki KUGO

Key Words：neonatal neuroblastoma，neuroblastoma size，prognostic value，prenatal ultrasonography

　在胎38 週出生の女児。妊婦健診時に，胎児エコーにて左上腹部に腫瘤が指摘された。腫瘤径は妊娠28 週時に最大となり，35 週頃から縮小し始め，生後も退縮傾向が持続した。腫瘤は一部に充実部，石灰化を伴う嚢胞性病変であり，尿中バニルマンデル酸，ホモバニリン酸および血中神経特異エノラーゼが高値を示し，123 I-MIBG シンチグラフィーで同部位に限局して集積を認めたことから，神経芽腫と診断した。診断後，転移所見や腫瘍随伴症状もなく，神経特異エノラーゼは速やかに低下した経過などから，両親の同意のもと無治療で経過観察とし，日齢27 に退院とした。以降，外来にて腫瘍の増大に関して慎重な経過観察を行っているが，1 歳1 か月の時点で腫瘍径は最大時の 1/4 程度まで縮小した。胎児期からの腫瘍径の推移と予後の関係性についての報告は乏しいが，胎児期より腫瘍の退縮傾向を認める新生児神経芽腫症例は予後良好である可能性がある。

　Neuroblastoma is the most common malignant solid tumor in childhood. It is well recognized that some screened neuroblastomas regress spontaneously. Here, we report a case of spontaneous regression of prenatally diagnosed neuroblastoma with a “watch and wait” strategy. The case was a female infant born at 38 weeks of gestation. A mass was detected from a routine fetal ultrasound in the left upper abdomen of the fetus at 23 weeks, which showed cystic and solid patterns with calcification. The size of the tumor increased until 28 weeks of gestation, and then spontaneously regressed until delivery. The infant’s prenatal growth was normal and there were no complications. The infant was born by spontaneous vaginal delivery at 38 6/7 weeks. After birth, the mass was diagnosed as neuroblastoma based on high levels of urinary vanilmandelic acid and homovanillic acid, serum neuron specific enolase, and the uptake of methyliodobenzylguanidine by the left adrenal gland. After obtaining informed consent from the parents, we applied a “watch and wait” strategy based on decreasing NSE levels, and no signs of metastasis or complications of neuroblastoma. The size of the tumor did not increase during the postnatal stay, and the infant was discharged at 27 days after birth with careful follow-up. The tumor size has since gradually decreased and is now almost 1/4 the maximum size at 1 year of age.
　There was no established evidence of the change in the size of the neuroblastoma during the prenatal periods and the prognosis. However, we speculate that prenatal regression of neuroblastoma may be associated with good prognostic value.