July 2026 - Neonatal POCUS Identification of Massive Hemoperitoneum in Congenital Metastatic Neuroblastoma

Introduction

We present an exceptionally rare neonatal case of congenital metastatic neuroblastoma complicated by traumatic hepatic rupture and massive hemoperitoneum at birth. This case highlights the critical role of neonatal POCUS in rapidly identifying hemorrhagic shock and a surgical abdomen in an unstable neonate, directly altering resuscitation and management.

Clinical Presentation

A term male infant was born at 39+6 weeks following induction of labor complicated by severe abdominal dystocia due to marked fetal abdominal distension. Delivery was further complicated by fetal decelerations and meconium-stained fluid.

At birth, the infant was profoundly depressed with severe metabolic acidosis, progressive abdominal distension, anemia, hypotension, and coagulopathy. Neurological examination was consistent with moderate hypoxic-ischemic encephalopathy (Sarnat II), and therapeutic hypothermia was initiated.

Given the unusual presentation, extensive investigations were initiated in the context of a very broad differential diagnosis, including:

• giant hepatic hemangioma with high-output cardiac failure and Kasabach-Merritt physiology,

• metabolic disease,

• congenital hepatic tumor,

• GALD

Role of POCUS and Sonographic Findings

A bedside POCUS examination was conducted while awaiting formal radiological evaluation in the context of rapid clinical deterioration, with worsening ventilatory compromise, refractory shock, progressive abdominal distension, and suspicion of abdominal compartment syndrome.

Abdominal POCUS Findings

·       Findings highly suspicious for hemoperitoneum:

• • Very large complex intra-abdominal fluid collection

  • Dependent echogenic layering within the fluid collection compatible with hematocrit layering

  • Significant mass effect on surrounding abdominal structures

• Additional findings:

  • Heterogeneous appearance of the liver

  • Large echogenic solid structure floating freely within the abdominal fluid collection

The floating echogenic structure was later confirmed during surgery to represent avulsed liver tissue. 

Cardiac POCUS Findings

• Grossly preserved biventricular systolic function

• No major evidence of severe primary myocardial dysfunction

Taken together, the POCUS findings rapidly shifted the working diagnosis toward catastrophic intra-abdominal hemorrhage with hemorrhagic shock and surgical abdomen, rather than isolated high-output cardiac failure.

Cranial and lung POCUS were also conducted with no evidence of IVH or pulmonary pathology that could have contributed to the acute deterioration.

These findings immediately prompted:

• activation of a massive transfusion protocol,

• urgent ultrasound-guided paracentesis yielding frank blood,

• emergency bedside laparotomy in the NICU,

• and subsequent interventional radiology embolization.

The ability of neonatal POCUS to identify hemoperitoneum in real time was critical in directing emergent surgical management in this unstable neonate.

Surgical Findings

Emergency bedside laparotomy revealed:

• Massive hemoperitoneum

• Avulsion of the left lateral liver segment

• Grossly abnormal liver tissue

The avulsed segment was resected, abdominal packing was performed, and the infant was transferred for emergent hepatic artery embolization.

Final Diagnosis

Autopsy demonstrated:

• Poorly differentiated congenital neuroblastoma

• Suspected bilateral adrenal primary tumors

• Massive hepatic metastatic involvement with near total tumoral replacement of hepatic tissue

• Placental metastatic disease with tumor emboli with signs of high-grade fetal vascular malperfusion

The extensive hepatic involvement likely contributed to profound hepatic fragility and subsequent traumatic rupture during delivery.

Teaching Points

• Congenital neuroblastoma is a rare neonatal malignancy, most commonly arising from the adrenal glands. While stage 4S neuroblastoma is generally associated with favorable outcomes, cases with extensive hepatic involvement represent a distinct and far more severe clinical entity.

• Massive hepatic metastatic infiltration in congenital neuroblastoma, classically referred to as Pepper syndrome, may lead to rapidly progressive abdominal distension, respiratory compromise, abdominal compartment syndrome, hepatic dysfunction, coagulopathy, and liver failure.

• Placental involvement in congenital neuroblastoma is exceptionally rare, with fewer than 20 cases reported in the literature. Placental tumor emboli and fetal vascular malperfusion likely contributed to the severe perinatal depression and hypoxic-ischemic presentation observed in this case.

• Extensive hepatic replacement by metastatic disease may result in profound hepatic fragility, predisposing to traumatic hepatic rupture during delivery. Only very few neonatal cases of traumatic hepatic rupture associated with congenital neuroblastoma have been documented in the literature.

• This case illustrates how congenital neuroblastoma with diffuse liver involvement may initially mimic giant hepatic hemangioma or high-output cardiac failure, creating significant diagnostic uncertainty in the neonatal period.

• Neonatal abdominal POCUS can rapidly identify life-threatening hemoperitoneum at the bedside through recognition of:

  • complex intra-abdominal fluid,

  • hematocrit layering,

  • mass effect,

  • and abnormal floating echogenic tissue.

• In this case, bedside POCUS immediately changed management by redirecting the diagnostic approach toward hemorrhagic shock and surgical abdomen, prompting urgent paracentesis, massive transfusion, bedside laparotomy, and embolization.

• Cardiac POCUS demonstrating preserved ventricular function was also clinically useful in helping differentiate hemorrhagic shock from severe primary cardiac dysfunction or isolated high-output heart failure physiology.

References:

1)Kume A, Morikawa T, Ogawa M, Yamashita A, Yamaguchi S, Fukayama M. Congenital neuroblastoma with placental involvement. Int J Clin Exp Pathol. 2014 Oct 15;7(11):8198-204. PMID: 25550872; PMCID: PMC4270547.

2) Ribeiro Aguiar B,Ribeiro J,Martins D,Noéme Prado S,Cavaco H. Perinatal neuroblastoma: a case report of pepper syndrome. Port J Pediatr.. 2025;56(3):177-181. Available from: http://dx.doi.org/10.24875/PJP.23000040

3) Lode HN, Henze G, Siebert N, Ehlert K, Barthlen W. Management of tumor rupture and abdominal compartment syndrome in an infant with bilateral high risk stage 4 neuroblastoma: A case report. Medicine (Baltimore). 2019 Aug;98(34):e16752. doi: 10.1097/MD.0000000000016752. PMID: 31441848; PMCID: PMC6716702.