RESEARCH LETTER

Prenatal diagnosis of exophytic nevus sebaceous of the scalpFerdinand Dhombres1, Kamila Kolanska1, Catherine Garel2, Jean-Pierre Aubry3, Marie Gonzales4 and Jean-Marie Jouannic1

1Service de Gynécologie-Obstétrique et Centre Pluridisciplinaire de Diagnostic Prénatal de l’ Est Parisien, Hôpital Armand Trousseau, APHP, Paris, France2Service de Radiopédiatrie, et Centre Pluridisciplinaire de Diagnostic Prénatal de l’ Est Parisien, Hôpital Armand Trousseau, APHP, Paris, France3Centre d’Echographie, Paris, France4Unité de Foetopathologie et Centre Pluridisciplinaire de Diagnostic Prénatal de l’ Est Parisien, Hôpital Armand Trousseau, APHP, Paris, France*Correspondence to: Jean-Marie Jouannic. E-mail: jean-marie.jouannic@trs.aphp.fr

ABSTRACTNevus sebaceous is a complex hamartoma most commonly found on the scalp, face, and neck and is often present atbirth, although some may be diagnosed later in infancy. We report the first prenatal diagnosis of isolated nevussebaceous that presented at 19weeks’ gestation as a large and exophytic tumor of the scalp. This case emphasizesthe crucial role of ultrasound examination performed with high-frequency probes, which revealed associated diffuselesions of the face. Identification of such a facial involvement could have a dramatic prognostic impact. © 2013 JohnWiley & Sons, Ltd.

Funding sources: NoneConflicts of interest: None declared

CASE REPORTA 29-year-old patient was referred to our centre at 19 + 5weeks’gestation for further evaluation of abnormal images of the fetalscalp. Both parents were Caucasian, unrelated, and with nopersonal or familial medical history. The woman had had oneearly miscarriage, and the couple had one healthy 3-year-oldboy. During this third pregnancy, a chorionic villous samplingwas performed at 12 + 5weeks’ gestation because of an estimatedcombined risk for Down syndrome of 1/17 (nuchaltranslucency: 4.7mm, crown-rump length: 62 mm). Becauseof first trimester increased nuchal translucency, ultrasound(US) examination was performed at 18 + 5 weeks’ gestation.The nuchal fold was 6mm, and several tumors were observedon the fetal scalp. The US performed in our institution showedseveral homogeneous scalp tumors mostly located on thevertex and the occiput (Figure 1A) with similar echogenicityto the adjacent hypodermis and showed no vascularizationwith color Doppler. They were frequently pedunculated,floating freely in the amniotic fluid, and presented withvariable length and thickness (maximum: 15 and 6mm,respectively). There was neither underlying skull defect norapparent connection between the tumors and the adjacentbrain tissue. Moreover, the use of a high-frequency probe (7–14MHz linear array transducer Aplio; Toshiba, Tokyo,Japan) revealed irregularities on the surface of the fetal facewith numerous sessile tiny tumors raising concern aboutdiffuse lesions covering the fetal face (Figure 1B). Because offetal presentation, only one earlobe was visible, which wasdeformed by lesions. No other anomalies were noted, and

the fetal biometry was appropriate for gestational age. Theappearance of the tumors was compared with previouslypublished cases of tumors of the scalp in neonates,1,2 as wewere unable to find any similar case reported in the prenatalliterature. Our case presented morphological characteristicsthat were very similar to exophytic nevus sebaceous (NS)described in neonates. The parents were informed that thiscondition was very likely and that it involved not only thescalp but also the face. A fetal skin biopsy was consideredbut was declined by the parents. They were informed by apediatric plastic surgeon that a complete postnatal excisionof the tumors could be considered but would require massivetissue expansion to aid closure of large defects. In order toevaluate the possible growth of the tumors, an additional USexamination was performed at 22weeks’ gestation andshowed that they were stable over time. The parentalinformation included the possibility of associated geneticdiseases with nevus sebaceous and concern for their childbeing disfigured whatever the surgical techniques used. Theparents opted for termination of the pregnancy, which wasperformed at 24weeks’ gestation. Postmortem examinationof the fetus confirmed the diagnosis of NS with extensivelesions of the scalp, the face, the eyelids, and the ears(Figure 2). Few tiny lesions were also found on the trunk,arms, and one thigh. No other anomalies were noted.

DISCUSSIONNevus sebaceous is a hamartoma most commonly found onthe scalp, face, and neck. It represents approximately one half

Prenatal Diagnosis 2013, 33, 1305–1307 © 2013 John Wiley & Sons, Ltd.

DOI: 10.1002/pd.4252

of all epidermal nevus with an estimated incidence of 0.3%during infancy.3 NS are often present at birth, although somemay be diagnosed later in infancy. In neonates, the mostcommon presentation of NS is a salmon to yellow color, hairless,and flat tumor with a smooth waxy surface, which may accountfor these lesions being overlooked by prenatal US.4,5 We reportthe very first case of prenatal diagnosis of isolated NS thatpresented at 19weeks’ gestation as large and exophytic tumorsof the scalp. Our diagnostic suspicion was based on the greatsimilarity of the sonographic appearance of these lesions withthe description by Correale et al.1 in three neonates and by Linet al. in another neonate.2 Our case emphasizes the crucial roleof US performed with high-frequency probes, which revealedassociated diffuse lesions of the face, whereas only largeexophytic lesions of the scalp were visible on US with low-frequency probes. Identification of such a facial involvementhad a dramatic prognostic impact. We considered performing

fetoscopy for diagnostic purposes even if US findings werehighly evocative of the diagnosis and of poor surgical possibilities,but the parents declined this invasive procedure.

The natural history of NS includes three main stages.5 Inthe initial stage during infancy, the lesion remains relativelyflat because of the quiescence of sebaceous glands. At puberty,under hormonal influence, NS show a rapid growth withtransformation of the lesion from a smooth into a verrucousplaque. The third stage is characterized by the developmentof benign and malignant neoplasms that may occur in 10% to15% of the cases. The NS are localized on the scalp in two-thirds of cases and in one-third, on the face. Some moreextensive forms involving scalp, face, neck, and thorax areobserved in 5% of the cases.6

The NS may be isolated or associated with extra-cutaneousabnormalities. The incidence of associated anomalies isnot precisely known and probably overstated because of

Figure 1 Ultrasound performed at 19weeks and 5 days (A) with a low-frequency probe (3–5MHz), lateral view of the skull showing severalscalp tumors at the level of the vertex (arrow) and the occiput (dotted arrow) and (B) with a high-frequency probe (7–14MHz), axial view ofthe face at the level of the mandibular bone (open arrow) showing irregularities of the surface of the fetal face with numerous sessile tinytumors (arrows)

Figure 2 Postmortem examination of the fetus with nevus sebaceous showing large and extensive congenital papillomatous lesions of thescalp, the face, the eyelids, the ears (arrow), and the cheek. These tumors are hairless, cerebriform with pedunculated parts (*)

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Prenatal Diagnosis 2013, 33, 1305–1307 © 2013 John Wiley & Sons, Ltd.

ascertainment bias.5 A broad spectrum of abnormalities thatmay affect all systems, including central nervous system (braintumor, hemimegalencephaly, and enlargement of the lateralventricles) and ocular (coloboma, cataract, retinal anomalies,strabismus, and ocular hemangioma) and skeletal anomalies(localized fibrous dysplasia of the skull, bone-forming structures,hypoplasia of the skeleton, and scoliosis) have been described.5

Schimmelpenning et al. were the first to report such associations7

but because of the great variety of abnormalities described, it ispreferable to use the termNS syndrome.8 In a consecutive seriesof patients with NS referred by their pediatricians over a 16-yearperiod, neurological manifestations were observed in 7% ofcases9: among affected cases, 75% had seizures and up to 60%had mental retardation. It is noteworthy that neuroimaging wasnormal in the majority (75%) of these affected patients. NSsyndrome is sporadic, and thewide variety of clinical expressionssuggests that the pathogenesis of this syndrome is based ongenetic mosaicism.5

Historically, NS was treated by full-thickness dermal andepidermal excisions before puberty mainly to prevent malignantdegeneration.4,10 Although this strategy has been a matter ofdebate in recent years, excision is still justified for cosmeticreasons, particularly for lesions involving the face.4,10 However,the surgical treatment of larger lesions requires tissue expansion,skin grafting with uncertain cosmetic results for extensive lesionsas observed in our case.

In conclusion, we report the first case of prenatal diagnosis ofNS, which illustrates the great difficulty of prenatal counseling inthis situation because of possible extra-cutaneous anomaliesincluding the risk of mental retardation. It also demonstratesthe contribution of US examination using high-frequencyprobes, which may provide substantial help in the analysis offacial involvement of this condition.

ACKNOWLEDGEMENTThe authors thank Dr Sylvie Fraitag who performs thehistological postmortem examination of this case.

WHAT’S ALREADY KNOWN ABOUT THIS TOPIC?

• Nevus sebaceous (NS) is a complex hamartoma most commonlyfound on the scalp, face, and neck.

• The NS appears as a flat tumor, which may account for theselesions being overlooked by prenatal ultrasound.

WHAT DOES THIS STUDY ADD?

• This study shows that prenatal diagnosis of NS is feasible byultrasound as early as 19weeks’ gestation.

• Using high-frequency probes can reveal diffuse lesions of the face.

REFERENCES1. Correale D, Ringpfeil F, Rogers M. Large, papillomatous, pedunculated

nevus sebaceus: a new phenotype. Pediatr Dermatol 2008;25:355–8.2. Lin HC, Lee JY, Shieh SJ, Hsu CK. Large, papillomatous and

pedunculated nevus sebaceus. J Dermatol 2011;38:200–2.3. Jones EW, Heyl T. Naevus sebaceus. A report of 140 cases with special

regard to the development of secondary malignant tumours. Br JDermatol 1970;82:99–117.

4. Moody MN, Landau JM, Goldberg LH. Nevus sebaceous revisited.Pediatr Dermatol 2012;29:15–23.

5. Sugarman JL. Epidermal nevus syndromes. Semin Cutan Med Surg2007;26:221–30.

6. Rogers M. Epidermal nevi and the epidermal nevus syndromes a reviewof 233 cases. Pediatr Dermatol 1992;9:342–4.

7. Schimmelpenning G. Klinisher Beitrag zur Symptomatologie derPhakomatosen. Fortschr Geb Rontgenstrahl 1957;87:712–16.

8. Solomon LM, Esterly NB. Epidermal and other congenital organoidnevi. Curr Probl Pediatr 1975;6:1–56.

9. Davies D, Rogers M. Review of neurological manifestations in 196patients with sebaceous naevi. Australas J Dermatol 2002;43:20–3.

10. Chepla KJ, Gosain AK. Giant nevus sebaceus: definition, surgicaltechniques, and rationale for treatment. Plast Reconstr Surg2012;130:296e–304e.

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Prenatal Diagnosis 2013, 33, 1305–1307 © 2013 John Wiley & Sons, Ltd.