An Atlas of Lumps and Bumps: Part 10

AUTHORS:
Alexander K. C. Leung, MD^1,2 —Series Editor • Benjamin Barankin, MD³ • Joseph M. Lam, MD⁴ • Kin Fon Leong, MD⁵

AFFILIATIONS:
¹Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
²Alberta Children’s Hospital, Calgary, Alberta, Canada
³Toronto Dermatology Centre, Toronto, Ontario, Canada
⁴Department of Pediatrics and Department of Dermatology and Skin Sciences, University of British Columbia, Vancouver, British Columbia, Canada
⁵Pediatric Institute, Kuala Lumpur General Hospital, Kuala Lumpur, Malaysia

CITATION:
Leung AKC, Barankin B, Lam JM, Leong KF. An atlas of lumps and bumps, part 10. Consultant. 2021;61(11):e22-e24. doi:10.25270/con.2021.10.00010

DISCLOSURES:
Dr Leung is the series editor. He was not involved with the handling of this paper, which was sent out for independent external peer review.

CORRESPONDENCE:
Alexander K. C. Leung, MD, #200, 233 16th Ave NW, Calgary, AB T2M 0H5, Canada (aleung@ucalgary.ca)

EDITOR’S NOTE:
This article is part of a series describing and differentiating dermatologic lumps and bumps. To access previously published articles in the series, visit https://bit.ly/35J1I1v.

Sebaceous Hyperplasia

Sebaceous hyperplasia is a common and benign proliferation and enlargement of normal sebaceous glands.¹ This condition affects approximately 1% of the general population.¹ Although sebaceous hyperplasia can occur in individuals of all races, it is more commonly observed in White patients.² The condition is seen mainly in middle-aged and elderly individuals, with a slight male predominance.^3-5  Premature sebaceous hyperplasia, on the other hand, occurs mainly during or soon after puberty without gender predominance.⁴ Transient sebaceous hyperplasia is not uncommon in newborns, which may result from exposure to maternal sex hormones.⁶ Other predisposing factors include reduction in androgen levels with advancing age, increased ultraviolet light exposure, immunosuppression, hemodialysis, pachydermatosis, Muir-Torre syndrome, and X-linked hypohidrotic ectodermal dysplasia.^3-5,7,8

Sebaceous hyperplasia usually presents as an asymptomatic solitary papule or, more commonly, as multiple discrete, yellow or flesh-colored, dome-shaped papules with central umbilication (Figure 1).^3,4 Individual lesions are usually 2 to 5 mm in diameter. Typically, lesions occur in areas where sebaceous glands are abundant. The forehead, cheeks, and nose are the most commonly affected areas.^1,5 Other, much less common sites of involvement include the chest, neck, nipple, areola, scrotum, penis, vulva, and buccal mucosa.

The diagnosis is usually clinical and can be aided by dermoscopy. Dermoscopy of a typical lesion shows central umbilication surrounded by a well-defined, milky-white cloud-like structure ("cumulus sign").⁹ This is also known as the "bonbon toffee sign," as this feature simulates a bonbon toffee.¹⁰  Arborizing blood vessels (blood vessels with multiple tree-like branches) and nonarborizing  and "wreath-like" blood vessels at the periphery of the lesion ("crown vessels") can also be seen.^9,10  Sometimes the ostium of the sebaceous gland is visible as a small crater or umbilication in the center of those yellow nodules.¹ Reflectance-mode confocal microscopy shows enlarged sebaceous lobules consisting of cuboidal cells with centrally located nuclei and a dilated sebaceous duct.¹¹ A skin biopsy should be considered if the diagnosis is in doubt, since basal cell carcinoma can occasionally mimic this lesion.

Seborrheic Keratosis

Seborrheic keratosis is a common benign cutaneous tumor composed of epidermal keratinocytes, seen mainly in people older than age 50 years.^12-14 Seborrheic keratosis is more prevalent among individuals with lighter skin color.^12,15 The sex ratio is approximately equal.¹²

Characteristically, the lesion presents as an asymptomatic, sharply demarcated, round or oval plaque with a “stuck on” warty appearance (Figure 2).^14,15 It is typically light to dark brown in color but may be yellow, grey, or even black.^12,16 At times, lesions may appear oily, waxy, and shiny, hence giving rise to the misnomer “seborrheic” (greasy) keratosis.¹⁵ Lesions can be solitary or numerous.¹² Seborrheic keratosis can appear almost anywhere on the body but spares the palms, soles, and mucosal surfaces.¹⁵ Sites of predilection include the face, scalp, chest, back, and extremities.^17,18

Occasionally, the lesion may bleed or become painful or itchy because of friction with clothing. Rarely, seborrheic keratosis occurs in association with other cutaneous neoplasms, notably basal cell carcinoma.¹⁹ The occurrence of seborrheic keratosis in association with squamous cell carcinoma, Bowen disease, keratoacanthoma, and malignant melanoma has also been described.¹⁹ It is unclear whether these tumors develop directly from seborrheic keratosis or whether, more likely, the lesions appear coincidentally because of advanced age.¹⁵

Many authors suggest that the sudden eruptive appearance of numerous seborrheic keratoses, especially on the trunk (Figure 3), may herald the presence of an internal malignancy, in particular adenocarcinoma of the gastrointestinal tract (Leser-Trélat sign).^20-22 Some authors, however, disagree.²³ On the other hand, this association appears to be even stronger in the presence of concomitant pruritus and acanthosis nigricans.¹⁵

Dermoscopy is a noninvasive diagnostic tool to confirm the clinical diagnosis. The most common dermoscopic features include comedo-like openings, milia-like cysts, fingerprint-like structures, fissures and ridges, hairpin blood vessels, moth-eaten border, network-like structures, and sharp demarcation.^14,24,25 When the contact dermoscope is moved horizontally over the lesion, the lesion of seborrheic keratosis, but not the other features, will follow the dermoscope (Wobble test).²⁴ Typical features seen with in-vivo reflectance confocal microscopy include a cerebriform shape in the epidermis, bright dermal papillary rings, and looped vessels at the abnormal dermal papillae.²⁶

References

1. Farci F, Rapini RP. Sebaceous Hyperplasia. In: StatPearls. StatPearls Publishing; September 9, 2021. http://www.ncbi.nlm.nih.gov/books/nbk562148/

2. Tagliolatto S, Alchorne MM, Enokihara M. Sebaceous hyperplasia: a pilot study to correlate this skin disease with circulating androgen levels. An Bras Dermatol. 2011;86(5):917-923. https://doi.org/10.1590/s0365-05962011000500009

3. Ranasinghe GC, Friedman AJ. Eruptive sebaceous hyperplasia: a rare consequence of systemic corticosteroids. J Drugs Dermatol. 2018;17(1):118-120. https://jddonline.com/articles/dermatology/S1545961618P0118X

4. Wang Q, Liu JM, Zhang YZ. Premature sebaceous hyperplasia in an adolescent boy. Pediatr Dermatol. 2011;28(2):198-200. https://doi.org/10.1111/j.1525-1470.2011.01233.x

5. Yu C, Shahsavari M, Stevens G, Liskanich R, Horowitz D. Isotretinoin as monotherapy for sebaceous hyperplasia. J Drugs Dermatol. 2010;9(6):699-701. https://jddonline.com/articles/dermatology/S1545961610P0699X

6. Kanada KN, Merin MR, Munden A, Friedlander SF. A prospective study of cutaneous findings in newborns in the United States: correlation with race, ethnicity, and gestational status using updated classification and nomenclature. J Pediatr. 2012;161(2):240-245. https://doi.org/10.1016/j.jpeds.2012.02.052

7. Levandoski KA, Girardi NA, Loss MJ. Eruptive sebaceous hyperplasia as a side effect of oral tacrolimus in a renal transplant recipient. Dermatol Online J. 2017;23(5):13030/qt7x0125gz. https://escholarship.org/uc/item/7x0125gz

8. Richey DF. Aminolevulinic acid photodynamic therapy for sebaceous gland hyperplasia. Dermatol Clin. 2007;25(1):59-65. https://doi.org/10.1016/j.det.2006.09.001

9. Bryden AM, Dawe RS, Fleming C. Dermatoscopic features of benign sebaceous proliferation. Clin Exp Dermatol. 2004;29(6):676-677. https://doi.org/10.1111/j.1365-2230.2004.1612.x

10. Oztas P, Polat M, Oztas M, Alli N, Ustun H. Bonbon toffee sign: a new dermatoscopic feature for sebaceous hyperplasia. J Eur Acad Dermatol Venereol. 2008;22(10):1200-1202. https://doi.org/10.1111/j.1468-3083.2008.02827.x

11. Propperova I, Langley RG. Reflectance-mode confocal microscopy for the diagnosis of sebaceous hyperplasia in vivo. Arch Dermatol. 2007;143(1):134. https://doi.org/10.1001/archderm.143.1.134

12. Greco MJ, Bhutta BS. Seborrheic Keratosis. In: StatPearls. StatPearls Publishing; August 11, 2021. http://www.ncbi.nlm.nih.gov/books/nbk545285/

13. Kwon OS, Hwang EJ, Bae JH, et al. Seborrheic keratosis in the Korean males: causative role of sunlight. Photodermatol Photoimmunol Photomed. 2003;19(2):73-80. https://doi.org/10.1034/j.1600-0781.2003.00025.x

14. Rajesh G, Thappa DM, Jaisankar TJ, Chandrashekar L. Spectrum of seborrheic keratoses in South Indians: a clinical and dermoscopic study. Indian J Dermatol Venereol Leprol. 2011;77(4):483-488. https://doi.org/10.4103/0378-6323.82408

15. Hafner C, Vogt T. Seborrheic keratosis. J Dtsch Dermatol Ges. 2008;6(8):664-677. https://doi.org/10.1111/j.1610-0387.2008.06788.x

16. Brodsky J. Management of benign skin lesions commonly affecting the face: actinic keratosis, seborrheic keratosis, and rosacea. Curr Opin Otolaryngol Head Neck Surg. 2009;17(4):315-320. https://doi.org/10.1097/moo.0b013e32832d75e3

17. Kennedy C, Bajdik CD, Willemze R, De Gruijl FR, Bouwes Bavinck JN; Leiden Skin Cancer Study. The influence of painful sunburns and lifetime sun exposure on the risk of actinic keratoses, seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer. J Invest Dermatol. 2003;120(6):1087-1093. https://doi.org/10.1046/j.1523-1747.2003.12246.x

18. Zhang RZ, Zhu WY. Seborrheic keratoses in five elderly patients: an appearance of raindrops and streams. Indian J Dermatol. 2011;56(4):432-434. https://doi.org/10.4103/0019-5154.84754

19. Noiles K, Vender R. Are all seborrheic keratoses benign? Review of the typical lesion and its variants. J Cutan Med Surg. 2008;12(5):203-210. https://doi.org/10.2310/7750.2008.07096

20. Ceylan C, Alper S, Kilinç I. Leser-Trelat sign. Int J Dermatol. 2002;41(10):687-688. https://doi.org/10.1046/j.1365-4362.2002.01600.x

21. Karadag AS, Parish LC. The status of the seborrheic keratosis. Clin Dermatol. 2018;36(2):275-277. https://doi.org/10.1016/j.clindermatol.2017.09.011

22. Phulari RG, Buddhdev K, Rathore R, Patel S. Seborrheic keratosis. J Oral Maxillofac Pathol. 2014;18(2):327-330. https://doi.org/10.4103/0973-029x.140926

23. Fink AM, Filz D, Krajnik G, Jurecka W, Ludwig H, Steiner A. Seborrhoeic keratoses in patients with internal malignancies: a case-control study with prospective accrual of patients. J Eur Acad Dermatol Venereol. 2009;23(11):1316-1319. https://doi.org/10.1111/j.1468-3083.2009.03163.x

24. Takenouchi T. Key points in dermoscopic diagnosis of basal cell carcinoma and seborrheic keratosis in Japanese. J Dermatol. 2011;38(1):59-65. https://doi.org/10.1111/j.1346-8138.2010.01093.x

25. Wang JC, Liu J. A case of clonal seborrheic keratosis with characteristic dermoscopic features. Chin Med J (Engl). 2020;133(4):499-500. https://doi.org/10.1097/cm9.0000000000000630

26. Dai H, Jiang HY, Xu AE. In vivo reflectance confocal microscopy for evaluating seborrheic keratosis, verruca plana, syringoma and lichen nitidus. Skin Res Technol. 2021;27(2):272-276. https://doi.org/10.1111/srt.12934