Nevus sebaceus: a clinicopathological study of 168 cases and review of the literature

Combined Melanocytic Nevus and Nevus Sebaceus: A Case Series and Review of the Literature

ABSTRACT

Nevus sebaceus is a rare congenital hamartoma with clinical and histopathological features that change with puberty. It has been associated with a number of secondary neoplasms, most of which are thought to derive from follicular germ cells. In this article, the authors describe a total of 3 cases of combined melanocytic nevus and nevus sebaceus to highlight this rare finding.

Atypical Nevus Sebaceus at an Unusual Location Treated with Carbon Dioxide Laser: A Case Report

Nevus sebaceus (NS) or organoid nevus is an epidermal nevus comprising predominantly sebaceous glands with a prevalence of approximately 0.3% of the newborns. The initial clinical manifestations of NS are single or less commonly multiple yellowish patches with overlying alopecia, usually confined to the scalp. However, it can also appear on the face, preauricular area, and the neck. During puberty, skin lesions will turn into round or linear verrucous plaques accompanied with an increase in number due to the influence of androgens. As they progress, about 20% of the NS cases might turn into secondary tumors which can be benign or malignant (in 2.5% cases). NS can manifest as atypical lesions and may also arise on areas other than its predilection sites. A case of a lesion presented on an atypical location of an 18-year-old male patient treated with carbon dioxide (CO₂) laser was reported. Physical examination revealed skin-colored and blackish-brown papules arranged in groups on the left side of the patient's chest. Histopathological examination on a sample taken from one of the skin lesions on the chest showed hyperkeratosis, acanthosis, papillomatosis, and sebaceous hyperplasia, confirming the diagnosis of NS. The patient was treated with CO₂ laser, and clinical improvements were observed. Histopathological examination of NS is not routinely performed; however, it should be carried out when the lesion is atypical and presented at an unusual location, or there is a suspicion of malignancy.

Neurofibroma Within a Nevus Sebaceus: A Case Report

Nevus sebaceus most commonly presents as a yellow, alopecic plaque on the head or neck in childhood and evolves into a verrucous plaque at puberty. Numerous secondary tumors may arise within nevus sebaceus lesions. Tumors of mesenchymal origin have been rarely documented. We present a unique case of a patient who presented with a nevus sebaceus on the scalp. Excision of the tumor and subsequent histopathology of the lesion revealed a nevus sebaceus with a desmoplastic trichilemmoma, a tumor of follicular infundibulum, and a neurofibroma. This case highlights a rare finding of a mesenchymal tumor, and the first reported neurofibroma, arising in association with a nevus sebaceus.

Trichilemmoma Arising in a Sebaceous Nevus Successfully Treated with Cryotherapy

Nevus sebaceous of Jadassohn (NSJ) is a benign congenital hamartoma composed of follicular, adnexal appendages and epidermal hyperplasia. Various secondary neoplasms, mostly adnexal in origin, can arise within nevus sebaceous. We report the case of a 16-year-old female who had NSJ associated with trichilemmoma, which was successfully treated with cryotherapy. We found cryotherapy to be an effective, satisfactory therapy, with acceptable cosmetic results, especially for patients who have visible lesions that can be easily followed.

Genodermatoses associated with melanocytic nevi

Though melanocytic nevi are ubiquitous in the general population, they can also be key cutaneous manifestations of genetic syndromes. We describe genodermatoses associated with melanocytic nevi and discuss their clinical characteristics, cutaneous manifestations, underlying genetics, and, if applicable, guidelines for when genetic testing should be performed. We categorized these genodermatoses based on their association with congenital nevi, acquired nevi, or nevi whose first appearance is unknown. In many cases, the distinctive morphology or distribution of melanocytic nevi can be an important clue that an underlying genetic syndrome is present, allowing both the patient as well as family members to be screened for the more serious complications of their genetic disorder and receive education on potential preventative measures. As we continue to advance our understanding of how various genotypes give rise to the wide spectrum of phenotypes observed in these genodermatoses, we shall be able to better stratify risk and tailor our screening methods to clinically manage the heterogeneous manifestations of genodermatoses among these patients.

Epidermal Nevi: What Is New

This article reviews the clinical findings of epidermal nevi and their associated syndromes and provides an update on their pathogenic genetic changes as well as targeted therapies detailed to date.

A rare case of nevus sebaceous of the bilateral labia minora: A case report and review of literature

RATIONALE

Nevus sebaceous (NS) is a lesion caused by congenital hyperplastic disorder of the sebaceous glands. It commonly noted in the scalp and face and rarely in the trunk, neck, or oral mucosa. We present a rare case of a lesion arising in the genital region.

PATIENT CONCERNS

A 47-year-old woman complained of a gradual increase in the size of her bilateral labia minora over 2 years, which affected her sexual life and caused walking difficulty. She was admitted to the Department of Obstetrics and Gynecology. On physical examination, no ulcer, discharge, and vulval or vaginal bleeding were found. The bilateral inguinal lymph nodes were not palpable, bilateral labia minora were asymmetric, and the right side was evidently bigger than the left. The labia minora had serrated edges and numerous papillae with a maximum diameter of 0.5 cm. The vagina, cervix, and uterus with its attachments were normal. Blood samples tested negative for human immunodeficiency virus, human papilloma virus, hepatitis B virus, and hepatitis C virus.

DIAGNOSIS

A diagnosis of NS of the bilateral labia minora was made following histopathological examination of the resected specimen.

INTERVENTION

The bilateral labia minora lesions were resected general anesthesia on August 29, 2016. The operation was successful, and intraoperative blood loss was about 10 ml.

OUTCOMES

After 40 months of postoperative follow-up, no recurrence or appearance of other tumors were noted.

LESSONS

We recommend surgical removal of lesions in the genital area during adolescence or before adulthood. Adolescence may be the best period for surgical intervention owing to a greater risk of malignant change in adulthood. On the other hand, surgical risk should be avoided in children considering the low incidence of malignant transformation.

Identification of KRAS mutation in a patient with linear nevus sebaceous syndrome: a case report

Background

Linear nevus sebaceous syndrome (LNSS) is a rare genetic disease characterized by large linear sebaceous nevus typically on the face, scalp, or neck. LNSS could be accompanied by multisystem disorders including the central nervous system. Herein, we report gene mutational profile via whole exome sequencing of both lesional and non-lesional skin samples in a LNSS patient.

Case presentation

A 17-year-old girl presented with multisystem abnormalities, including large skin lesions, ocular disorders, abnormal bone development and neurological symptoms. A diagnosis of LNSS was established based on clinical manifestations, histopathological and imaging findings. The skin lesions were resected and no recurrence was noted at the time of drafting this report. Whole exome sequencing of genomic DNA revealed the following 3 mutations in the lesions of the index patient: KRAS (c.35G > A, p.G12D), PRKRIR (c.A1674T, p.R558S), and RRP7A (c. C670T, p.R224W), but no mutation was found in the healthy skin and peripheral blood sample of the index patient, or in the blood samples of her parents and sibling. PCR-mediated Sanger sequencing of DNA derived from lesional skin sample of the index patient verified KRAS mutation, but not PRKRIR (c.A1674T, p.R558S) and RRP7A (c. C670T, p.R224W). None of the 3 mutations was found in Sanger sequencing in skin lesions of 60 other cases of nevus sebaceous patients.

Conclusions

Our findings show the relevance of KRAS mutation to LNSS, providing new clues in understanding related genetic heterogeneity which could aid genetic counselling for LNSS patients.

Optimal Timing for Surgical Excision of Nevus Sebaceus on the Scalp: A Single-Center Experience

BACKGROUND

Treatment of nevus sebaceus (NS) on the scalp is usually surgical excision, but the optimal timing is debatable. The scalp presents significant challenges to the reconstructive surgeon because the lack of elasticity of the scalp makes the repair of defects difficult.

OBJECTIVE

The aim of this study was to investigate the optimal timing for surgical excision of NS on the scalp through postoperative outcomes.

METHODS

The authors retrospectively reviewed the postoperative cosmetic results of patients with a follow-up period of 12 to 15 months. The variables analyzed were patient demographics, preoperative tumor size, location, operative time, cosmetic results, and complications.

RESULTS

This study enrolled 62 patients, including 30 adults and 32 children. The main complications were hair loss, hypertrophic scar, and widening of the scar. The overall complication rate was 17.7%, and the complication rate in children (9/32, 28.1%) was higher than that in adults (2/30, 6.7%) (p < .05). Tumor location, shape, and size showed no association with complications.

CONCLUSION

Complications after surgical excision of NS on the scalp are more likely to occur in children than in adults. On the basis of these findings, surgical excision of NS on the scalp can be delayed until after childhood.

Sebaceous Nevus of the Scalp

Excisions of scalp nevus sebaceous (NS) presents a unique challenge due to limited soft tissue laxity, hair-bearing skin, and convex surfaces which often leave the surgeon and patient underwhelmed with the reconstructive outcome. In this study, the authors conducted an institutional review board-approved retrospective review of patients who underwent excision of pathologically proven scalp primary NS from 2003 to 2017 at our institution to better define the reconstructive outcomes and options for treatment of pediatric scalp NS. 92 patients were included in the study, 54 males (58.7%) and 38 females (41.3%). The average age at surgery was 7.24 years (0.5-16.0; SD 4.7). Local tissue undermining/galeal scoring with primary closure (LTUGS) was used for lesions with average surface area of 3.6 cm, rotational or transposition flaps (RF/TF) for lesions averaging 4.3 cm, completed serial excision for lesions averaging 13.9 cm, and tissue expansion (TE) for lesions averaging 21 cm (P <0.001). One or more poor outcomes were experienced by 35 patients (38%), with a significant difference between the surgical groups; LTUGS 37.2% (29/78), RF/TF 60% (3/5), serial excision 100% (3/3), TE 0% (0/6) (P = 0.022). Univariant binary regression analysis within the LTUGS and RF/TF groups showed that lesion size was a significant predictor of poor outcomes (P = 0.012). All specimens in this study were negative for carcinoma. Therefore, most pediatric nevus sebaceous of the scalp can be managed by a single-phase procedure though risk of poor outcomes increase with nevus size with high rates of poor outcomes even with small lesions.

Aplasia cutis congenita of the scalp: Histopathologic features and clinicopathologic correlation in a case series

BACKGROUND

Aplasia cutis congenita (ACC) is a rare and heterogeneous disorder characterized by congenital absence of skin. The scalp is the most commonly affected site and lesions may overlie deeper ectodermal abnormalities. The exact etiology is still unknown, and histopathologic features are poorly defined.

METHODS

A series of 10 cases from nine patients was analyzed to characterize the clinicopathologic spectrum and age-related changes of ACC of the scalp. Hematoxylin and eosin, S100, Elastica van Gieson, and Weigert elastic stains were performed, and clinical information was retrieved from archived medical files.

RESULTS

Patient ages ranged from 1 day to 39 years (median 57 months). All cases resembled deep-reaching scars with almost complete loss of all adnexal structures. Isolated residual hair follicles were present in 8/10 and sweat glands and ducts in 2/10 cases. The subcutis was thinned or absent. Elastic fibers were always more fragmented than in normal tissue, and the thickness and density increased over time. There was no gain of adnexal structures with increasing age.

CONCLUSIONS

ACC represents a congenital scarring alopecia with permanent loss of skin appendages. Histopathologic changes resemble a deep-reaching scar with fragmented elastic fibers and differentiate ACC from all other forms of non-traumatic congenital alopecias.

Lichen Planopilaris Developing at the Margins of a Sebaceous Nevus of Jadassohn: Co-existence or Etiologic Association?

Sebaceous nevus (SN), is a skin hamartoma, combining a variety of epidermal, follicular, sebaceous, and apocrine abnormalities. Although usually present at birth, it may become apparent later in life appearing as a yellowish-brown, verrucous plaque with alopecia. SN is implicated with secondary tumors arising on the hairless plaque during the adulthood. Lichen planopilaris is a common, primary lymphocytic scarring alopecia of unknown etiology, characterized by lichenoid/interface perifollicular lymphocytic infiltrate occurring at the level of the infundibulum and the isthmus. Here, we present a case of a 48-year-old Caucasian male with lichen planopilaris lesions developing at the periphery of a preexisting SN. Our case raises the question, whether the development of lichen planopilaris was coincidental, or is it indicative of an etiologic association between the lichen planopilaris and SN.

Syringocystadenoma papilliferum and trichoblastoma arising in the nevus sebaceous

Nevus sebaceous (NS) is a clinically common benign tumor and has a high potential to develop into a great diversity of neoplasms of epidermal and adnexal origins. However, it is a rare phenomenon of the coexistence in a single NS with two or more skin tumors. We report a case of a 58-year-old woman with two kinds of neoplastic proliferation including syringocystadenoma papilliferum and trichoblastoma arising in NS on the scalp.

Rare desmoplastic trichilemmoma associated with sebaceous nevus

Nevus sebaceous of Jadassohn is a congenital hamartoma that usually affects the scalp and face. Several benign or malignant neoplasias may develop in the lesion and the most common are trichoblastoma, syringocystadenoma papilliferum, and basal cell carcinoma. Trichilemmoma is a benign solid tumor originating from external sheath cells of pilosebaceous follicles. When it is characterized by a central zone of desmoplasia, it is called desmoplastic trichilemmoma. We report a case of a 58-year-old patient who developed a tumor in a sebaceous nevus. We performed a total excision of the lesion. Histopathological diagnosis was compatible with desmoplastic trichilemmoma. Our literature review reveals that the occurrence of trichilemmoma desmoplastic is unusual. Moreover, it can mimic an invasive carcinoma on histological and clinical examinations. This fact confirms the importance of reporting the occurrence of this rare cancer in a nevus sebaceous of Jadassohn.

Syndromic sebaceous nevus: current findings

BACKGROUND

Sebaceous nevus is a congenital malformation of the skin that usually occurs on the scalp or face. Syndromic forms do rarely exist with associated cerebral and ocular malformations. The skin lesions are pale at birth and become irregular by puberty. In the adult patient, tumors (usually benign) develop from sebaceous nevus. Their surgical excision during childhood can give a better result in terms of the definitive scar.

OBJECTIVES

The aim of this study is to analyze our cases of syndromic sebaceous hamartoma, perform a review of the existing literature, and propose guidelines for the therapeutic plan.

METHODS

This is a retrospective study reviewing the cases of syndromic sebaceous nevus treated in the Department of Orthopedic Plastic Pediatric Surgery in Montpellier, France, and the Department of Pediatric Surgery in Lausanne, Switzerland, between 1994 and 2016.

RESULTS

The files of six patients with syndromic sebaceous nevus were analyzed. The average age at the first consultation was 4 months. The location was craniofacial in all cases. Cerebral radiological imaging was performed on all patients; two showed abnormal findings. Four patients underwent ophthalmic examination, which all revealed abnormalities. Three patients had other associated malformations. Three patients presented with epilepsy or learning difficulties in the course of follow-up.

CONCLUSION

All patients presenting with extensive sebaceous nevus of the craniofacial region should benefit from cerebral imagery and ophthalmic examination since there is a very high probability of associated abnormalities. The developmental problems encountered could not be definitively associated with the skin malformations.