Dermatology: Practical and Conceptual DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Observation | Dermatol Pract Concept 2014;4(1):16 93 Case presentations Case 1 A 39-year-old Japanese man presented with 6-month history of a group of papules on the chest (Figure 1A). The patient had no specific symptoms, such as itching or tenderness, but visited the clinic worried about the long duration of the lesions. Physical examination showed pinkish white, firm papules of 5 to 10 mm in diameter with sharply demarcated borders. The surface of the papules was smooth and shiny. Dermoscopic examination demonstrated aggregation of yellowish-white clods with linear vessels between or above the clods exhibiting reticular distribution as a whole (Fig- ure 1B). Other papules also showed similar features. High dynamic range (HDR) [1,2] conversion of the dermoscopy photograph further clarified the multi-lobulated clods with a central opening (Figure 1C). Histopathological examination of the biopsied lesions established the diagnosis of sebaceous hyperplasia (SH) (Figure 1D). Based on the clinical, dermo- scopic and histopathological findings, the final diagnosis was linear SH on the chest. Case 2 A 32-year-old Japanese woman presented with a 5-year his- tory of linearly arranged papules on the upper chest (Figure 2A). The patient was asymptomatic, including itching or tenderness. Physical examination showed yellowish-white, firm papules up to 5 mm in diameter with a clear border. The surface of the papules was smooth and shiny. Dermoscopic examination demonstrated aggregation of yellowish-white clods with vague linear vessels surrounding the clods (Figure 2B). All other papules showed similar features. HDR image conversion of the dermoscopy photograph further clarified the multi-lobulated clods and the surrounding vessels (Figure 2C). Based on the clinical and dermoscopic findings, a diag- nosis of linear SH on the chest was established. Discussion SH represents benign proliferation of the sebaceous gland and tends to appear on the forehead and temples of middle-aged or elderly people [3]. It has also been reported in the vulva, penis and areola [4]. Familial forms have also been reported [4]. To our knowledge, this is the second and the third cases of linear SH on the chest, but the SH in our cases are not on the midline of the anterior chest as described in the first report [5]. Our cases were sporadic and not familial but the distribution of the papules seems to be along the Blaschko line, suggesting that SH in our cases might have occurred as a result of mosaic mutation. Linear sebaceous hyperplasia on the chest Toshitsugu Sato1, Masaru Tanaka2 1 Sato Dermatology Clinic, Tokyo, Japan 2 Department of Dermatology, Tokyo Women’s Medical University Medical Center East, Tokyo, Japan Keywords: sebaceous hyperplasia, linear arrangement, chest, dermoscopy, high dynamic range, image conversion Citation: Sato T, Tanaka M. Linear sebaceous hyperplasia on the chest. Dermatol Pract Concept. 2014;4(1):16. http://dx.doi.org/10.5826/ dpc.0401a16 Received: June 9, 2013; Accepted: June 14, 2013; Published: January 31, 2014 Copyright: ©2014 Sato et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Toshitsugu Sato, M.D., Sato Dermatology Clinic, 1-7-3 Kami-Ogi, Suginami-ku, Tokyo 167-0043, Japan. Tel. +81 3 5397 3663; Fax: +81 3 5397 3663. Email: sato3663@gmail.com 94 Observation | Dermatol Pract Concept 2014;4(1):16 Accurate diagnosis of SH is necessary, although no treat- ment is required in most cases. References 1. Sato T, Tanaka M. Improved detection of dermoscopic struc- tures by high dynamic range image conversion. Jpn J Dermatol. 2013;123:121-31. 2. “High dynamic range imaging.” http://en.wikipedia.org/wiki/ High_dynamic_range_imaging, 2013. Accessed June 1, 2013. 3. Layton AM. Disorders of the sebaceous glands. In: Rook’s Text- book of Dermatology. 8th ed. West Sussex: Wiley-Blackwell, 2010. 4. Ahmed TSS, Preore JD, Seykora J. Tumors of the epidermal ap- pendages. In: Lever’s Histopathology of the Skin. 10th ed, Phila- delphia: LWW, 2009:872. 5. Jeong TJ, Shin MK, Lee MH. Linear sebaceous hyperplasia on the chest. Clin Exp Dermatol. 2009;34(7):e366-7. 6. Kato N, Yasuoka A. “Giant” senile sebaceous hyperplasia. J Der- matol. 1992;19(4):238-41. Several more variants of SH have been reported. For example, a giant form of 10 mm in diameter has been reported on the cheek [6] and four cases with a linear arrangement have been reported on the pre- and retro-auricular, neck and chin areas. Each papule in these four cases ranged from 2 to 5 mm in diameter and formed a plaque measuring up to 1.5 cm wide x 8 cm long [7]. In another case of the linear type, the papules appeared on the juxta-clavicular beaded lines. They were small in size, 0.5-1.5 mm in diameter, and exhibited a linear arrangement on the supra- or subclavicular areas [8]. The exact pathological mechanism of SH is unknown though the condition is associated with advanced age, ultra- violet irradiation and immunosuppression therapy especially cyclosporine A alone or in combination with corticosteroids [9]. SH is not directly associated with malignant disorders, although sebaceous neoplasms have been reported to be association with internal malignancy in the setting of Muir- Torre syndrome [10]. A B C D Figure 1. Case 1. (A) A group of papules on the chest with linear distribution pattern. (B) Dermoscopy of sebaceous gland hyperplasia. Note the aggregation of yellowish-white clods with linear vessels between or above the clods. (C) Dermoscopy of sebaceous gland hyperplasia followed by HDR image conversion. Note the multi-lobulated clods with central openings. (D) Hematoxylin and eosin staining of biopsied lesion of sebaceous gland hyperplasia: Note the multiple, mature sebaceous lobules attached to the central dilated duct in the upper dermis. Original magnification x25. [Copyright: ©2014 Sato et al.] http://en.wikipedia.org/wiki/High_dynamic_range_imaging http://en.wikipedia.org/wiki/High_dynamic_range_imaging Observation | Dermatol Pract Concept 2014;4(1):16 95 9. Zouboulis CC, Boschnakow A. Chronological ageing and pho- toageing of the human sebaceous gland. Clin Exp Dermatol. 2001;26(7):600-7. 10. Schwartz RA, Torre DP. The Muir-Torre syndrome: a 25-year retrospect. J Am Acad Dermatol. 1995;33(1):90-104. 7. Fernandez N, Torres A. Hyperplasia of sebaceous glands in a lin- ear pattern of papules. Report of four cases. Am J Dermatopathol. 1984;6(3):237-43. 8. Franco G, Donati P, Muscardin L, Maini A, Morrone A. Juxta- clavicular beaded lines. Australas J Dermatol. 2006;47(3):204-5. A B Figure 2. Case 2. (A) Multiple papules on the chest showing linear ar- rangement. (B) Dermoscopy of sebaceous gland hyperplasia. Note the aggregation of yellowish-white clods with vague linear vessels sur- rounding the clods. (C) Dermoscopy of sebaceous gland hyperplasia followed by HDR image conversion. Note the multi-lobulated clods with central openings and surrounding vessels. [Copyright: ©2014 Sato et al.] C