Case Presentation: A 3,400 gram male infant was born at full term to a 32 year old G1P0>1 mother with unremarkable prenatal labs. Labor was complicated by prolonged rupture of membranes, foul smelling amniotic fluid, and maternal fever of 100.5°F. The infant was delivered vaginally. After initial resuscitation, the infant was started on antibiotics due to concerns of maternal chorioamnionitis. Initial CBC at 24 HOL showed WBC of 14,200 and platelets of 73,000. Repeat platelet count on DOL 3 was 59,000, and six hours later was 36,000, prompting transfer to a Level III NICU.
On admission, infant was afebrile with stable vitals, well appearing, and normal cardiopulmonary exam. Abdominal exam revealed a left upper quadrant palpable mass 1.5cm below the subcostal margin. Abdominal ultrasound and subsequent MRI revealed a large, heterogeneous, solid mass replacing lateral segment of left hepatic lobe. AFP level was significantly elevated at >36,300 ng/mL, quantitative beta-hCG and urine for catecholamines levels were normal. Based on these findings, a diagnosis of rapidly involuting congenital hemangioma (RICH) was made.

The infant’s NICU course was notable for a petechial rash and mild transient coagulopathy with prolonged PTT, low fibrinogen, and abnormal D-Dimer. These findings resolved with cryoprecipitate and fresh frozen plasma. The infant was discharged home with plans for close follow up with both the pediatrician and pediatric hematologist.

Discussion: RICH are rare benign vascular neoplasms of infancy which are fully formed at birth and shrink rapidly in infancy without intervention. They may either be cutaneous or hepatic. RICH is often asymptomatic but can be associated with a mild self-limited transient thrombocytopenia and deranged coagulation profile. This consumptive coagulopathy is distinct from the Kasabach-Merritt syndrome, which is associated with profound thrombocytopenia, fibrinogen consumption, and secondary formation of D-dimer.

Definitive diagnosis of RICH is achieved through biopsy. However, biopsy is invasive and presents a bleeding risk. In lieu of biopsy, the diagnosis can be made with the heterogeneous appearance on US, CT, or MRI. A decreasing size of the lesion and a decreasing serum AFP can be helpful in supporting the diagnosis.

Treatment of RICH is supportive as both the lesion and mild coagulopathy are anticipated to resolve without intervention. Treatment with corticosteroids is needed only if the patient is symptomatic, the lesion is persistent, or for cosmetic purposes if it involves a visible location. In rare cases, arteriovenous shunting can lead to high-output cardiac failure requiring embolization.

Conclusions: Rapidly involuting congenital hemangiomas are rare, benign vascular tumors of infancy. They are typically asymptomatic but can cause a transient coagulopathy. Awareness of this diagnosis can prevent invasive tests or unnecessary medical treatment of an otherwise benign condition