Encephalocraniocutaneous Lipomatosis without Neurologic Anomalies

Dear Editor:

Encephalocraniocutaneous lipomatosis (ECCL) is a rare, sporadically occurring congenital neurocutaneous syndrome that characteristically involves ectomesodermal tissues, such as the skin, eyes, and central nervous system (CNS). Since it was first described by Haberland and Perou1 in 1970, the majority of new cases of ectomesodermal dysgenesis have been reported using the term ECCL.

A 1-month-old Asian male was referred for dermatologic evaluation of patchy alopecia located in the frontotemporal region. The hairless patch had been noted at birth. Physical examination revealed a soft, somewhat elevated, area of patchy hair loss in the frontotemporal region (Fig. 1a). A biopsy of the hairless scalp revealed diffuse loss of hair follicles and thickening of the subcutaneous fatty tissue with lobular proliferation (Fig. 2A). The clinical and histologic findings of the scalp lesion were consistent with nevus psiloliparus, which is considered a hallmark of ECCL. No sign of scalp inflammation or scarring was found. Additionally, some papular lesions had been present on the forehead and periocular area since birth (Fig. 1b) and eyelid coloboma and epibulbar choristoma on left eye were observed during an ophthalmologic investigation (Fig. 1c, d). The constellation of findings met the criteria for ECCL2. A neurological examination including brain magnetic resonance imaging performed to identify any neurologic anomalies was normal (Fig. 2B). The electrocardiogram and echocardiography showed no evidence of congenital heart defects.

Fig. 1
(a) Patchy hair loss in the frontotemporal area. (b) Erythematous papular lesions were seen on the forehead and periocular area. (c) Epibulbar choristoma on the left eyeball. (d) Eyelid coloboma.

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Fig. 2
(A) Biopsy specimen from the scalp showed no significant dermal, perifollicular, or subcutaneous fibrosis. The thickness of the subcutaneous adipose tissue was increased with lobular proliferation of mature subcutaneous fatty tissue and fewer hair follicles (H&E ×40). (B) Magnetic resonance imaging reveals an oval image suggestive of a lipoma, about 2 cm sized, in left parietal paramedian area of the scalp (arrow). No abnormal signal intensity lesion in the brain parenchyme.

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ECCL is a sporadically occurring neurocutaneous disorder of unknown etiology. The hypothesized genetic mechanism involves lethal autosomal dominant genes that survive by mosaicism, and the pathogenesis most likely involves dysgenesis of the cephalic neural crest and anterior neural tube3.

Clinically, ECCL is characterized by unilateral cutaneous and ophthalmologic lesions with CNS anomalies and some authors have proposed diagnostic criteria2. The skin anomalies associated with ECCL include small nodular skin tags in the periocular area or on the eyelid, subcutaneous lipomas of the scalp, and patchy or streaky nonscarring alopecia with or without underlying fatty tissue. The hairless fatty tissue nevus of the scalp is called a nevus psiloliparus, and was once regarded as pathognomic of ECCL. However, nevus psiloliparus with no other features associated with ECCL has also been reported as an independent non-syndromic skin disorder4. Although a few reports have showed ECCL without CNS anomalies5, various CNS anomalies have been detected in ECCL, including hemiatrophy, dilated ventricles, porencephalic cysts, abnormal calcifications, intracranial lipomas, and cranial asymmetry2. The degree of the intracranial anomalies with ECCL does not correspond with the extent of associated skin and eye findings. There may be accompanying mental retardation or epilepsy. The neurodevelopmental spectrum is broad, from normal development to severe retardation2. Because mild retardation or severe retardation are seen in roughly two-thirds of ECCL patients in developmental data2, long term follow-up is needed to detect further abnormal neurodevelopment.

When confronted with congenital hairless lesions of the scalp, clinicians must consider the diagnosis of nevus psiloliparus and keep in mind its association with ECCL. They need to investigate other possible anomalies associated with ECCL using a multidisciplinary evaluation and follow-up by a neurosurgeon, pediatrician, ophthalmologist, and plastic surgeon.