Rapidly involuting congenital hemangioma (ORPHA:141184)
Rapidly involuting congenital hemangiomas (RICH) are a distinctive type of congenital hemangioma that are fully formed in utero and differ from non-involuting congenital haemangiomas (NICH; see this term) mainly because they undergo rapid postnatal involution.
Epidemiology
Prevalence is unknown but the lesions appear to be rare.
Clinical description
RICH have long been confused with infantile immature hemangiomas but are now clearly distinguished on the basis of their distinctive clinical, histological and immunephenotypic features. RICH are round or oval-shaped, solitary and raised or infiltrating vascular tumors that are most commonly located close to a joint on the limbs, or on the scalp, forehead or around the ear. They develop in utero but there is no postnatal growth and involution is achieved in about 1 year. RICH located on the scalp seem to originate from the subperiosteal region and may permeate the vault bone during fetal life, a defect that heals after birth as the tumor regresses. The surface of RICH may be mildly or massively telangiectatic, with telangiectasia radiating from the centre in some cases, resulting in varying hues from pink to purple. A ring of pallor of variable size encircles the tumor. A central linear scar, depressed area or necrotic wound may be observed. In a few cases, the overlying skin appears almost normal. After regression, two types of sequelae can occur: lipoatrophy with a white-bluish skin hue, or a telangiectatic plaque. The term hepatic RICH has been applied to a solitary, involuting vascular liver tumor in newborns that, in resected cases, shows similar pathological features to those of external RICH.
Etiology
The etiology of RICH is unknown.
Diagnostic methods
Imaging studies are useful for diagnosis and should include color Doppler ultrasound (revealing a high-flow vascular tumor), and postnatal, and often antenatal MRI (showing a heterogeneous tumor with cystic aspects and calcifications). When clinical and radiological data are ambiguous, a biopsy is indicated in the newborn. Pathologic studies of RICH reveal large and densely cellular lobules, areas of fibrosis, and other lobules with larger vessels of irregular shape. GLUT1, the phenotypic marker for infantile hemangioma, is negative in RICH.
Differential diagnosis
RICH must be differentiated from other congenital vascular tumors, tufted angiomas and kaposiform hemangioendotheliomas, as well as from other congenital possibly benign (infantile myofibromatosis) or malignant tumors (rhabdomyosarcoma or fibrosarcoma; see these terms). In rare cases, moderate transient thrombocytopenia occurs in the first week of life: this should not be misdiagnosed as Kasabach-Merritt syndrome (see this term).
Antenatal diagnosis
Antenatal diagnosis of RICH during prenatal ultrasound follow-up is feasible in the 3rd trimester, and sometimes as early as the 20th week of pregnancy. Elevated rates of arterial supply and venous drainage are associated with these large tumors. They are best imaged with MRI in the 3rd trimester, not only for diagnostic purposes but also to enable decisions to be made concerning a vaginal or caesarean delivery.
Genetic counseling
Genetic counseling should not be recommended as the lesion is sporadic.
Management and treatment
Management is often limited to observation until the end of spontaneous involution. In case of residual lesions, surgical lipofilling can be considered for a bluish atrophoderma, and surgical resection for a reddish-pink plaque. Early resection in the neonatal period is only performed for lesions in selected locations, when there is a risk of hemorrhage (ulceration and fast-flow vessels located underneath the RICH). Occasionally, corticosteroid treatment may be beneficial for very large lesions.
Prognosis
The prognosis is good; however, a few exceptional cases of fatal hemorrhage have been reported.

                            Last update: 
                            September 2008


                            - Expert reviewer(s): 
                            Dr Odile ENJOLRAS  - Pr Marie-Paule VAZQUEZ