Letter: multiple large cysts arising from nevus comedonicus.

I read with interest the article entitled "Multiple Large Cysts Arising from Nevus Comedonicus" by Jeong et al. [1]. I believe it is very difficult to cure nevus comedonicus (NC), as I have experienced performing repeated surgery for NC. The authors described a magnetic resonance imaging (MRI) scan that detected 5 cystic masses, but there were three resected masses and sets of physical findings. Upon viewing the figures, I wondered where the two masses were. Of the three resected masses, one mass is shown in a different MRI image than the others. Is there a histopathologic difference between them?

NC shows the clinical appearance of grouped, often linearly arrayed, elevated follicular openings. With time, the follicular openings fill with dark keratin plugs, imparting the appearance of open comedones [2]. Previously reported treatments include dermabrasion, extraction, numerous topical keratolytics (retinoic acid, 12% ammonium lactate lotion, tacalcitol, a combination of tazarotene and calcipotriene cream) and laser (CO2 laser, Erbium: YAG laser). In case of giant NC, excision and tissue expansion is acceptable [3].

Some patients have often suffered from repeated infections and abscesses, and are often keen to undergo a more definitive procedure. I have reported a case of a 15-month-old girl with NC on her cheek who had undergone treatment of the lesion by excision [4]. She had periodic episodes of erythema and swelling of plaque. Topical retinoid cream was ineffective. I excised only the main linear lesion with cysts leaving the satellite papules to prevent a deformity and hypertrophic scar (Figs. 1, 2). Since then, she has undergone two more operations as new papules filled with dark plugs and several epidermal cysts developed (Figs. 3, 4). There are no more cysts, but several dark plugs have remained around the incision scar for more than 1 year since the last operation.

Fig. 1

A 15-month-old girl has multiple papules filled with dark plugs and cystic masses on her cheek. (Courtesy of Korean Cleft Palate-Craniofacial Association. From Kim YJ, et al. J Korean Cleft Palate-Craniofac Assoc 2009;10:135-7 [4]).

Fig. 2

Intraoperative photograph. Several epidermal cysts were seen (Courtesy of Korean Cleft Palate-Craniofacial Association. From Kim YJ, et al. J Korean Cleft Palate-Craniofac Assoc 2009;10:135-7 [4]).

Fig. 3

Result at 8 months after the first operation. New papules and cysts were developed around the scar.

Fig. 4

Result at 1 year after the 2nd operation.

As far as I am concerned, surgical excision is the best choice for treating NC with cysts or recurrent infection. However, we cannot confirm the border of the nevus, as the opening is very small. We do not know when and where a new lesion might develop, so I disapprove of the early radical resection recommended by Jeong et al. [1]. Excessive excision leaves a severe scar and may require reconstructive surgery.

Lastly, when a paper is published, the references should be identical to the original article. The authors comment that the sentence "Histopathological analysis reveals that the skin appendage tumors include dilated pore of Winer, pilar sheath acanthoma, and trichilemmal cyst" is cited from my paper as reference 7; this content does not appear in my article. The two papers report similar cases, so it would have been better if they had emphasized the differences between the two cases.