Seborrheic keratosis is one of the most common benign epidermal skin tumors 1. Its pathogenesis remains largely unclear. Aging, genetic predisposition, and ultraviolet light may play a role in the pathogenesis of these lesions 2–5.
The prevalence of seborrheic keratosis increases with age; however, lesions can also appear at relatively young ages 6,7. Seborrheic keratosis can appear anywhere on the body, with the exception of the palms and soles. The most commonly affected sites are the chest, back, head (near the temples), and neck. Lesions may be solitary, but more often, they are disseminated in large numbers, especially in older patients 8.
Histologically, seborrheic keratosis is characterized by acanthosis, papillomatosis, hyperkeratosis, and horn pseudocysts. Depending on how prominent these features are, seborrheic keratosis may be grouped into different histological subtypes. The most important of these are the acanthotic, hyperkeratotic, and adenoid 8.
The lesions are well demarcated, round, or oval neoplasias. They may be skin-colored, light brown or black, and appear stucked on the skin surface. Stucco keratosis and dermatosis papulosa nigra are considered to be clinical variants of seborrheic keratosis. Leser–Trelat syndrome, another clinical variant, is a rare paraneoplastic syndrome, which is most commonly associated with adenocarcinoma and eruption of multiple seborrheic keratoses 8.
Although seborrheic keratosis is a benign disorder, there are various indications for the removal of lesions: exclusion of malignancy (if the clinical appearance is unclear), irritation with inflammation, and especially cosmetic concerns in patients with multiple lesions. The treatment of choice includes a range of office procedures such as curettage, shave excision, electrodesiccation, cryotherapy, and ablative lasers (e.g. CO2 laser ablation). The use of topical and systemic drug therapies in the treatment of seborrheic keratosis has not yet been widely adopted 8–10.
The aim of this work was to compare electrocautery and CO2 laser ablation in the treatment of seborrheic keratosis through clinical and histopathological assessment.
Patients and methods
This study was carried out on 30 patients with seborrheic keratoses. They were selected from among those attending the Outpatient Clinic of Dermatology and Venereology Department in Tanta University Hospitals during the period from December 2011 to December 2012. The study was approved by the Research Ethics Committee of the Faculty of Medicine, Tanta University. All participants signed an informed consent before enrollment in the study. Patients enrolled in this study were divided randomly according to the line of treatment into two equal groups: group A included 15 patients with seborrheic keratosis in whom the lesions were ablated by electrocautery in one or two sessions at 2-week intervals. Electrocautery was performed using a Surtron 50 D device (manufacture by LED SpA, Rome, Italy), a high-frequency electrosurgical equipment for monopolar minor surgical procedures. The electrosurgery unit was adjusted to a low-power setting and started at 0.8 W (range 0.6–1.0 W). Group B included 15 patients with seborrheic keratosis in whom the lesions were ablated by CO2 laser in one or two sessions at 2-week intervals. CO2 laser ablation was performed using a Sharplan silk touch 1055 S CO2 laser (manufacture by DEKA, Florence, Italy) apparatus. The lesions were ablated using an energy density of 7–12 J/cm2 (square or polygonal scanning pattern), 4–8 mm diameter ‘spot size’ cycle mode pause, and 0.4 s ‘pulse duration’.
Assessment of the efficacy of the treatment
Assessment of the clinical efficacy
Efficacy of the treatment was evaluated 1 month after the end of treatment and at the end of the follow-up period (6 months) by estimating the mean value of two different opinions; two contant physicians’ opinions, evaluators were not blinded, and the patients’ opinions. This evaluation was performed on the basis of colored photographs of the lesions taken before the treatment, after treatment (weekly for 1 month), and then during follow-up (monthly for 6 months). This evaluation included cosmetic outcome and occurrence of post-therapy complaints, complications, and recurrence. The cosmetic outcome was categorized as follows 11:
- Excellent: 76–100% improvement.
- Very good: 51–75% improvement.
- Good: 25–50% improvement.
- Fair: <25% improvement.
Assessment of the histopathological efficacy
Before initiating the treatment, a 3 mm punch skin biopsy specimen was taken from the lesion in all patients and stained by H&E to confirm the diagnosis. One month after the end of the treatment, another punch skin biopsy was taken from the treated area to study histopathological skin changes of each treatment modality.
Continuous variables were presented as mean±SD and discrete variables were shown as numbers and percentages. Both χ2 and Fischer s exact test testing were used for intergroup comparisons, and P less than 0.05 was considered significant. SPSS Software (Version 16.0 statistical package for Microsoft Windows; SPSS Inc., Chicago, Illinois, USA) was used throughout.
A total of 30 patients with seborrheic keratoses completed this study. Fifteen patients (50%) were men and fifteen patients (50%) were women. Their age ranged from 38 to 71 years, with a mean of 60.73±11.10 years. Their clinical data are presented in Table 1.
The clinical efficacy of the treatment was exactly the same in both groups A and B (Figs 1 and 2): excellent in 10 patients (66.7%), very good in four patients (26.7%), and good in the remaining patient (6.7%) (Fig. 3).
Comparison between groups A and B for the overall occurrence of post-therapy patient complaints (pain, erythema, edema, and pruritus) showed that there was no statistically significant difference (P=0.984) (Table 2).
In terms of post-therapy complications, wound infection and scarring occurred only in one patient (6.7%) in group A, whereas there was no post therapy infection or scarring in group B (0%). Post inflammatory hyperpigmentation was recorded in three patients in group A (20%), whereas it was recorded in two patients (13.3%) in group B. Hyperpigmentation was transient and improved within 3 months in all patients. There was no statistically significant difference between the two groups in the occurrence of post-therapy complications (Table 2).
The recovery time was comparable in both groups, with no statistically significant difference between the two groups (Table 3).
Incomplete recurrence of some lesions occurred only in three patients, all from group B (20%), whereas none of the patients in group A showed any recurrence of lesions. There was no statistically significant difference between the two groups in the recurrence rate.
The histological efficacy of both treatment modalities was almost the same. Before treatment, the epidermis showed hyperkeratosis, acanthosis, papillomatosis, and pseudohorn cysts whereas the dermis showed no histological abnormalities (Fig. 4).
After treatment, the epidermis of all patients in group A (100%) and group B (100%) showed a decrease in hyperkeratosis, decreased thickness of the epidermis, loss of rete ridges, loss of papillomatosis, and disappearance of pseudohorn cysts. The dermis showed edema and increased vasculature. However, three patients (20%) in group B showed hyperkeratosis, acanthosis, and pseudohorn cysts, indicating remaining seborrheic keratosis. These three patients experienced incomplete recurrence of some lesions during the follow-up period. In these cases, the dermis showed edema, increased vasculature, and homogenization of the collagen. There was subepidermal separation in some patients, mostly a form of scar blister artifact (Figs 5 and 6).
Interest and innovation in electrosurgery have increased recently. Practitioners have realized that superficial ablation, deep ablation, and tissue incision with immediate hemostasis are possible through electrosurgery 12. Thus, the aim of this work was to compare the clinical and histopathological efficacy of electrocautery versus ablative CO2 laser in the treatment of seborrheic keratosis. In this study, comparison between both modalities in the clinical efficacy showed that there was no statistically significant difference. This is in agreement with Hafner and Vogt 8, who reported that the treatment of choice of seborrheic keratoses covers a range of office procedures such as electrodesiccation, cryotherapy, and ablative lasers (e.g. erbium YAG or CO2 laser). Depending on the availability and the physician’s experience with each, these methods are all relatively equally suitable.
All patients in this study were evaluated for post-therapy complaints (pain, edema, pruritus, and erythema). It was found that there was no significant difference between the two groups in the overall occurrence of post-therapy complaints. Grekin et al. 13 studied the efficacy and the safety of electrosurgical facial resurfacing on their patients with mild to severe photodamage and reported that clinically significant adverse effects in their patients were unusual. Krupashankar 14 reported that CO2 laser in the resurfacing of some benign skin lesions leads to thermal injury to denuded skin. Almost all patients encounter minor side effects ranging from postoperative pain and edema to pruritus and tightness.
In the current study, the mean duration of healing in patients treated with CO2 laser was less than those treated with electrosurgery. This might be because of the sealing effect of CO2 laser on the blood vessels and lymphatics as well as its sterilizing effect 15. However, there was no significant difference between the two groups in the healing time. This may be attributed to the fact that the depth of tissue destruction and the subsequent thermal damage of both therapeutic modalities, electrodesiccation and CO2 laser, are the same.
Grekin et al. 13 reported that after electrosurgical ablation, wound healing and recovery time was almost similar to that found after CO2 laser ablation.
All patients in this study were followed up monthly for 6 months to evaluate the post-therapy complications. It was found that there was no significant difference between the two groups in the occurrence of post-therapy complications. This was in agreement with Grekin et al.13 and Burns et al. 16, who reported that safety evaluation of electrosurgical ablation was similar to that observed after the use of CO2 laser.
In the current study, the frequency of post-therapy complications was minimal in both groups and hyperpigmentation occurred only in a few patients. Garcia et al.17 studied the removal of dermatosis papulosa nigra lesions with either electrodesiccation, curettage, or pulsed dye laser and found that hyperpigmentation was the most common adverse outcome, which resolved within 6 months with or without treatment.
Krupa Shankar et al.18 and Krupashankar 14 reported that although hyperpigmentation after CO2 laser resurfacing is frequent in coloured patients, it is usually minimal and improves gradually. Also, Nanni and Alster 19 reported that hyperpigmentation was the most common complication after laser ablation. The pathogenesis of hyperpigmentation is not clear, but dermal injury may be the main reason for this in these patients, producing significant inflammation, leading to activation of the dermal melanocytes 20. Pigmentary abnormalities can also occur particularly if postoperative instructions to avoid sun exposure are disregarded. Good postoperative skin care and the use of sunscreen can prevent this complication 21.
In the current study, recurrence of the lesions occurred only in three patients; these patients were from group B. Hafner and Vogt 8 reported that after removal of seborrheic keratoses, local recurrence can occur; given the relationship between the incidence of seborrheic keratosis and increasing age, the appearance of de novo tumors is also to be expected after the removal of multiple lesions.
Evaluation of the histological efficacy of both treatment modalities showed that there was no significant difference between both groups. After treatment, the epidermis was thin and showed a decrease in hyperkeratosis, loss of rete ridges, loss of papillomatosis, and disappearance of pseudohorn cysts. The dermis showed edema and increased vasculature. However, in three patients in group B, some remaining microscopic features of seborrheic keratosis were observed. These patients showed incomplete recurrence of some lesions during the follow-up period. The explanation for this may be the presence of the lesions in sun-exposed areas and the frequent exposure of those patients to sun light, which results in rapid subsequent recurrence of the lesions after ablation. Another explanation could be incomplete removal (residue of the tumor). This may be because of the presence of a dermal component in these cases accidentally and CO2 laser ablates only the epidermal component.
On review of the literature, few studies comparing electrocautery and CO2 laser ablation in the treatment of seborrheic keratosis were available. Garcia et al.17 concluded that the efficacy of pulsed dye laser in the treatment of dermatosis papulosa nigra was not significantly different from the already established treatment modalities of electrodesiccation and curettage. Kundu et al.11 reported that the treatment of dermatosis papulosa nigra with KTP laser and electrodesiccation showed comparable efficacy. Also, Grekin et al. 13 and Burns et al.16 compared electrosurgical resurfacing with other resurfacing techniques, especially CO2 laser resurfacing, in the treatment of some epidermal lesions. They concluded that the outcomes of electrosurgical resurfacing were similar to those of other resurfacing techniques.
Both electrodesiccation and CO2 laser ablation are highly effective, with satisfactory cosmetic outcomes, in the treatment of seborrheic keratosis. CO2 laser is an effective therapeutic modality, but it is relatively expensive and needs a longer learning curve to be mastered. Electrosurgery is a simple, easy, cheap, and effective therapy, although it is an old modality. The devices are small in size, portable, and easy to use. There is no light beam; therefore, no eye protection is required, eliminating the need for expensive wavelength-rated spectacles and potentially irritating intraocular shields. Electrosurgery is a re-emerging treatment modality that may represent a solid alternative for laser therapy in many dermatological aspects, with similar cosmetic outcomes. Therefore, it is strongly recommended that more researches be carried out to determine the safe use of this cost-effective treatment modality in the field of dermatology, especially in the era of facial resurfacing and ablation of benign and malignant skin growth.
Conflicts of interest
There are no conflicts of interest.
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