Human papillomavirus type 59 identified in a verrucous cyst of the flank

ARTICLE

Auteur(s) : Haeryoung Kim¹, Jae Yeon Seok¹, Se Hoon Kim¹, Nam Hoon Cho¹, Won Soon Chung², Seung-Kyung Hann², Kwang Gil Lee³

¹Department of Pathology, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, Korea
²Dr. Woo’s Skin Clinic and Esthetic, 15-3 Galwol-dong, Yongsan-gu, Seoul, Korea
³Department of Pathology, Yonsei University Wonju Medical College, 162 Ilsan-dong, Wonju, Kangwondo, Korea

accepté le 3 Janvier 2006

Case report

Histological examination with routine hematoxylin-eosin stain revealed a cyst located in the deep dermis, lined by an acanthotic squamous epithelium with areas of papillomatosis (figure 1A). Hyperkeratosis was prominent especially at the tips of the papillomatous elevations, and large, prominent, irregular keratohyaline granules and pyknotic nuclei were noted in the granular layer. No definite koilocytotic features were seen (figure 1B). The outer surface of the cyst was relatively smooth except for a focus where squamous eddies were present, creating a worrisome “infiltrative” appearance (figure 1C). There was no pore-like opening into the epidermal surface even on serial sections. The overlying epidermis was histologically unremarkable. The surrounding stroma showed a mild chronic inflammation, and no adnexal structures were found near the cyst wall.

Immunohistochemistry using a polyclonal antibody against papillomavirus capsid antigen (DAKO, Carpinteria, CA, USA) was performed by the avidin-biotin procedure, and positive staining was seen in some of the pyknotic nuclei in the granular layer (figure 1D).

HPV detection and genotyping was performed with extracted DNA using HPVDNAChip, a PCR-based DNA microarray system provided by Microarray Center, Biomedlab Co (Seoul, Korea). DNA was isolated from the paraffin-embedded tissue with a DNA isolation kit (Qiagen, Hilden, Germany), and target HPV DNA was amplified by a PCR with GP5d+/Gp6d+ primers (GP5d+, 5′-tttkttachgtkgtdgatacyac-3′; GP6d+, 5′-gaaahataaaytgyaadtcataytc-3′; k, g/ t; h, t/a/c; d, a/t/g; y, t/c). Beta-globin was amplified by PCR with PC03/PC04 primers (PC03, 5′-acacaactgtgttcactagc-3′; PC04, 5′-caacttcatccacgttcacc- 3′) for internal control. The amplified DNA was labeled by Cy5-dUTP (NEN; Life Science Products Inc, Boston, MA, USA). The HPV-amplified product and beta-globin-amplified products were denatured by the addition of 3N sodium hydroxide solution, incubated for 5 minutes at room temperature, neutralized with 1 mol L^–1 TRIS (tris-[hydroxymethyl]-aminoethane)–hydrochloric acid (pH 7.2) and 3N hydrochloric acid, and then finally cooled for 5 minutes on ice. The samples were mixed with a hybridization solution made of 6X SSPE (saline-sodium phosphate-EDTA buffer; Sigma Chemical Co, St Louis, MO, USA) and 0.2% sodium dodecylsulfate, and applied to the DNA chip. Hybridization was performed at 40°C for 2 hours and then washed with 3X SSPE for 2 minutes, 1X SSPE for 2 minutes, and air-dried at room temperature. Hybridized HPV DNA was visualized using a DNA Chip Scanner (Scanarray lite; GSI Lumonics, Ottawa, Canada). Of the 22 types of mucocutaneous HPV tested, the type 59 probe hybridized with the fragment amplified from our specimen (figure 2).

Discussion

Verrucous cysts differ from epidermoid cysts in the appearance of the cyst linings: acanthosis, papillomatosis, hypergranulosis with prominent keratohyaline granules, and hyperkeratosis, all being features reminiscent of HPV infection. Koilocytotic changes have also been sometimes reported, although they were not seen in our case. A striking feature in our case was the presence of squamous eddies in the cyst wall, resembling those seen in typical irritated seborrheic keratoses. Interestingly, five ‘epidermoid cysts with seborrheic verruca-like cyst walls’ have been previously reported [15] and described as showing acanthotic and papillomatous cyst linings, however, neither the presence of squamous eddies nor any relation to HPV were mentioned. Clinically, they are solitary lesions resembling epidermoid cysts and appearing most commonly on the face and back. They usually occur in adult patients, in contrast to common warts which are more prevalent in children or adolescents.

The verrucous cyst seen in our case showed histopathological features of HPV infection and also positivity for HPV capsid antigens by immunohistochemistry. However, this case is unique in that HPV genotyping demonstrated a homology to HPV type 59, a finding not previously mentioned. HPV type 59 is known to be a high-risk genital type, frequently detected in anogenital lesions such as cervical intraepithelial neoplasia and condylomata acuminate [16, 17]. HPV type 59 was initially cloned from a vulvar intraepithelial neoplasia and has been reported to show homology with HPV types 18, 45 and 39, which are also types associated with high-risk epithelial dysplasia. The detection of HPV type 59 in condylomata acuminata has been associated with immunosuppression [18]; however, our patient had no history or laboratory findings suggestive of immunosuppression.

Other than HPV-associated verrucous cysts and plantar epidermoid cysts, HPV has also been demonstrated in a verrucous trichilemmal cyst [6], and there are a few reports of molluscum contagiosum occurring in epidermoid cysts in the literature [19, 20]. The pathogenesis of cutaneous cysts associated with viral infection still remains obscure, however, it is postulated that the cysts may be induced by the virus de novo, or that the virus may infect pre-existing cysts [3-6]. Mechanical inclusion of HPV-containing epithelium into the dermis of weight-bearing areas has been suggested as a possible explanation for plantar epidermoid cysts [8, 9, 13], but this seems less likely to be the mechanism for cysts arising in non-plantar locations. Localization of the virus in the follicular ostia with subsequent obstruction and cyst formation, and epidermoid metaplasia of HPV-infected eccrine ducts have also been proposed as possible mechanisms for palmoplantar epidermoid cyst formation [21].

More than 10 years have elapsed since the verrucous cyst was first described in the literature [1], and although this may be an underreported entity, there have been no reports up to date implicating an aggressive behavior for these cysts, despite the proliferative features in the cyst walls which may appear alarming. However, as HPV type 59 is known to fall into the high-risk group in anogenital lesions, and as persistent infections of the skin with high-risk genital HPV types have been reported to represent a risk factor for non-melanoma skin cancer in non-immunosuppressed individuals [22], we suggest that it may be necessary to educate these patients about self-examination and to perform thorough in-office physical examinations on a regular basis for a better characterization of its clinical behavior.

References

2 Aloi F, Tomasini C, Pippione M. HPV-related follicular cysts. Am J Dermatopathol 1992; 14: 37-41.

3 Elston DM, Parker LU, Tuthill RJ. Epidermoid cyst of the scalp containing human papillomavirus. J Cutan Pathol 1993; 20: 184-6.

4 Soyer HP, Schadendorf D, Cerroni L, et al. Verrucous cysts: histopathologic characterization and molecular detection of human papillomavirus-specific DNA. J Cutan Pathol 1993; 20: 411-7.

5 Reis MD, Tellechea O, Baptista AP. Verrucous cyst. Eur J Dermatol 1998; 8: 186-8.

6 Misago N, Narisawa Y. Verrucous trichilemmal cyst containing human papillomavirus. Clin Exp Dermatol 2005; 30: 38-9.

7 Lutzner MA. The human papillomaviruses. A review. Arch Dermatol 1983; 119: 631-5.

8 Egawa K, Inaba Y, Ono T, et al. “Cystic papilloma” in humans? Demonstration of human papillomavirus in plantar epidermoid cysts. Arch Dermatol 1990; 126: 1599-603.

9 Kitasato H, Egawa K, Honda Y, et al. A putative human papillomavirus type 57 new subtype isolated from plantar epidermoid cysts without intracytoplasmic inclusion bodies. J Gen Virol 1998; 79: 1977-81.

10 Egawa K, Kitasato H, Honda Y, et al. Human papillomavirus 57 identified in a plantar epidermoid cyst. Br J Dermatol 1998; 138: 510-4.

11 Matsukura T, Iwasaki T, Kawashima M. Molecular cloning of a novel human papillomavirus (type 60) from a plantar cyst with characteristic pathological changes. Virology 1992; 190: 561-4.

12 Ashida M, Ueda M, Kunisada M, et al. Protean manifestations of human papillomavirus type 60 infection on the extremities. Br J Dermatol 2002; 146: 885-90.

13 Kashima M, Takahama H, Baba T, et al. Detection of human papillomavirus type 57 in the tissue of a plantar epidermoid cyst. Dermatology 2003; 207: 185-7.

14 Lee S, Lee W, Chung S, et al. Detection of human papillomavirus 60 in epidermal cysts of nonpalmoplantar location. Am J Dermatopathol 2003; 25: 243-7.

15 Rahbari H. Epidermoid cysts with seborrheic verruca-like cyst walls. Arch Dermatol 1982; 118: 326-8.

16 Rho J, Roy-Burman A, Kim H, et al. Nucleotide sequences and phylogenetic classification of human papillomavirus type 59. Virology 1994; 203: 158-61.

17 Bryan JT, Tekchandani J, Schroeder JM, et al. Propagation of human papillomavirus type 59 in the athymic mouse xenograft system. Intervirology 2000; 43: 112-8.

18 Brown DR, Schroeder JM, Bryan JT, et al. Detection of multiple human papillomavirus types in condylomata acuminata lesions from otherwise healthy and immunosuppressed patients. J Clin Microbiol 1999; 37: 3316-22.

19 Aloi F, Pippione M. Molluscum contagiosum occurring in an epidermoid cyst. J Cutan Pathol 1989; 12: 163-5.

20 Fellner MJ, Osowsky MJ. Molluscum contagiosum occurring in an epidermoid inclusion cyst. Int J Dermatol 1979; 18: 160-1.

21 Egawa K, Egawa N, Honda Y. Human papillomavirus-associated plantar epidermoid cyst related to epidermoid metaplasia of the eccrine duct epithelium: a combined histological, immunohistochemical, DNA-DNA in situ hybridization and three-dimensional reconstruction analysis. Br J Dermatol 2005; 152: 961-7.

22 Iftner A, Klug SJ, Garbe C, et al. The prevalence of human papillomavirus genotypes in nonmelanoma skin cancers of nonimmunosuppressed individuals identifies high-risk genital types as possible risk factors. Cancer Res 2003; 63: 7515-9.