Nevus sebaceous: A clinical and dermoscopic correlation– A case report and review of literature

INTRODUCTION

Nevus sebaceous, also known as organoid nevus, Jadassohn nevus or pilosyringosebaceous nevus, is categorised as a type of epidermal appendageal nevus that arises from the hyperplasia of epithelial, sebaceous, follicular and apocrine skin elements, primarily involving the sebaceous glands.^[1] This particular case is significant due to its extensive involvement of the scalp and face, as well as the correlation between dermoscopic findings and clinical observations. Dermoscopy, a non-invasive imaging technique, aids in diagnosis and is instrumental in monitoring disease progression to identify any potential malignant transformations, thus serving as both a diagnostic and prognostic modality, although histopathological examination is essential for conclusive disease confirmation.

CASE REPORT

A 14-year-old male, born from a non-consanguineous marriage, presented with complaints of a yellowish to hyperpigmented raised lesion over the right frontal region since birth. The lesion gradually progressed to involve the right forehead and extend to the nose, as well as involve the right cheek and upper lip. There was no history of other cutaneous or systemic issues, nor any similar complaints in the family. His developmental milestones were normal. Upon examination, a yellowish to hyperpigmented plaque with irregular margins and a mammillated surface, accompanied by hair loss, was observed over the right frontal region of the scalp, extending to the nose and also involving the right cheek and upper lip [Figures 1 and 2]. No other site was involved [Figures 3 and 4]. General, ocular, musculoskeletal, and central nervous system examinations were all within normal limits (ruling out any syndromic association). Dermoscopy revealed yellow globules clustered on a yellowish background, along with orange and brown globules and white scales [Figures 5-7]. The yellow globules correspond to numerous hyperplastic sebaceous glands, while the orange globules indicate immature sebaceous glands, and the brown globules represent hyperplastic, mature sebaceous glands. The presence of orange–brown globules suggests a transitional phase in slightly elevated plaques. The parents declined consent for a biopsy, which ideally should have been performed for diagnostic confirmation. The patient’s parents were counselled about the nature of the disease, its potential progression during puberty, and the various treatment options available, including their possible adverse effects. The patient was advised to come for follow-up if new lesions appeared or if there were rapid changes in texture, size, nodulation, or ulceration.

Close

Figure 1:

Figure depicting yellowish to hyperpigmented plaque characterised by irregular margins and surface mammillations, accompanied by hair loss over the right frontal scalp extending up to the nose and also involving the right cheek and the right upper lip.

Export to PPT

Close

Figure 2:

Lateral view depicting yellowish to hyperpigmented plaque characterised by irregular margins and surface mammillations, accompanied by hair loss over the right frontal scalp extending up to the nose and also involving the right cheek and the right upper lip.

Export to PPT

Close

Figure 3:

Sparing of all other body sites. (Chest, abdomen and b/l upperlimb).

Export to PPT

Close

Figure 4:

Sparing of all other body sites (neck and back).

Export to PPT

Close

Figure 5:

Dermoscopy of nevus sebaceous showing yellow globules clustered (black arrow) on a yellowish background and brown globules in a cobblestone pattern (black circle) along with yellow-whitish lobular appearance (black star).

Export to PPT

Close

Figure 6:

Dermoscopy showing brown–yellow globules (black arrow) and yellow homogenous structures (black circle) on a yellow background.

Export to PPT

Close

Figure 7:

Dermoscopy showing orange and brown globules (black star) along with white scales (black arrow) suggestive of transition phase.

Export to PPT

DISCUSSION

Nevus sebaceous is a rare condition that occurs in approximately 0.3% of newborns, with no gender bias.^[1] The growth observed during adolescence is linked to the rise in androgen levels at puberty, which affects pilosebaceous and apocrine structures. Clinically, the condition can be classified into three developmental stages based on morphology and age [Table 1].

Nevus sebaceous may be associated with Schimmelpenning– Feuerstein–Mims or linear nevus syndrome (characterised by lesions that exhibit a blaschkoid distribution with extracutaneous manifestations involving the neural, ocular, and skeletal systems) and Phakomatosis pigmentokeratotica.^[2-4] The common benign appendageal tumours include syringocystadenoma papilliferum and trichilemmoma.^[1] Neoplasms typically arise during the fourth decade of life, with basal cell carcinoma being the most frequently observed malignant tumour. Histopathological examination is essential for confirming the diagnosis.^[5] The differential diagnoses considered included nevoid sebaceous hyperplasia, wart, xanthogranuloma and mastocytoma. Nevoid sebaceous hyperplasia appears as multiple skin coloured to yellowish papules with central depressions, exhibiting no surface changes with age, predominantly located on the face. Warts are acquired and caused by human papillomavirus infection. They are contagious and may be present on the hands, feet, face and genitals. Xanthogranuloma is a type of non-Langerhans cell histiocytosis (lipid-laden histiocytes in skin) that appears as yellow or orange nodules on various body parts. Mastocytoma may appear as brown or yellowish lesions, often with a smooth surface and can cause symptoms such as itching or flushing. In contrast, nevus sebaceous presents as a solitary plaque at birth, usually asymptomatic, which develops an irregular and verrucous surface during puberty, most commonly located on the scalp.

Dermoscopy serves as a non-invasive imaging technique that aids in diagnosis. In our study, the dermoscopic characteristics of nevus sebaceous were consistent with those reported by Sandhu et al.^[6] Furthermore, Kelati et al.,^[7] which showed yellow globules clustered on a yellowish to pinkish yellow background, homogeneous yellow globules, brown and orange globules arranged in a cobblestone pattern, brown globules in a cerebriform pattern, along with greyish to white exophytic papillary projections, dotted to polymorphous vessels and yellow to white scales with crusted erosions. The dermoscopic differential diagnosis includes sebaceous adenoma and sebaceous hyperplasia, the latter exhibiting crown peripheral vascularisation against a yellow background and a central crater. Prophylactic excision is advisable for small lesions in childhood due to their risk of malignant transformation. Treatment options encompass excision, laser resurfacing, dermabrasion and photodynamic therapy.^[8] Patients should be informed about the potential benign and malignant tumours associated with this condition and encouraged to maintain regular follow-ups, reporting any changes in texture, colour, size, or the emergence of new neoplasms.

CONCLUSION

Dermoscopy is a non-invasive imaging tool that can aid in the diagnosis of nevus sebaceous. It may also be helpful in monitoring the progression of the disease to detect malignant transformation and hence serves as both a diagnostic and prognostic modality.