Keratoacanthoma in vitiligo lesion after UVB narrowband phototherapy

Mycosis fungoides patient accompanied actinic keratosis, actinic keratosis with squamous cell carcinoma transformation, and porokeratosis after NBUVB therapy - 1st case report and review of the literature

INTRODUCTION

Mycosis fungoides (MF) is the most common form of primary cutaneous T cell lymphoma. Narrowband ultraviolet B light (NBUVB) is used increasingly in treating MF because of its good toleration and well-established management.

CONCERNS

To discuss the risk factors and underlying pathogenic factors in the patients with secondary skin diseases after NBUVB therapy.

METHODS

We report in details the first case of a patient with MF accompanied with actinic keratosis (AK), AK with squamous cell carcinoma (SCC) transformation and porokeratosis after NBUVB therapy. Meanwhile, Sequence variants in tumor suppressor p53 gene in the patient's specimens were detected. A literature search of the key word "narrowband ultraviolet B light "and "side effects" was performed on PubMed, 14 cases of this entity were found. A total of 15 patients including our case were reviewed in this study and meaningful conclusion could be drawn.

OUTCOMES

The mean age at diagnosis of secondary skin dermatoses after NBUVB therapy was 62.08 years with a male to female ratio of 2:1. The cases were reported more in Europeans than in Asians (2.75:1), and the Fitzpatrick skin type was mainly Ito III (12/15). The mean cumulative number and cumulative dose of UVB treatments were 43.71 and 42, 400 (mJ/cm), respectively. There was a positive relationship between Fitzpatrick skin type and cumulative dose of UVB treatments. Among the secondary skin diseases after NBUVB treatment, 12 were tumors, 2 were non-tumorous dermatoses. Only our patient presented with both. By polymerase chain reaction-single nucleotide polymorphism (PCR-SNP) analysis, C-G mutation of exon 4 of p53 was found in AK and MF specimens in our patient.

CONCLUSION

To our knowledge, our case is the first MF patient accompanied with AK, AK with SCC transformation and Porokeratosis after NBUVB treatment. Lower Fitzpatrick skin type may be the risk factor of secondary skin diseases after NBUVB treatment.

Keratoacanthoma (KA): An update and review

Keratoacanthoma (KA) is a common but underreported tumor of the skin. Two striking features of KA are its clinical behavior with spontaneous regression after rapid growth and its nosological position on the border between benignity and malignancy. We review current knowledge on the clinical, histopathological, and dermoscopic features of KA to ensure a proper diagnosis and describe its variants, including different types of multiple KAs. We highlight current concepts of KA ethiopathogenesis with special emphasis on the genetic background of multiple familial KA, the role of Wnt signaling pathway, and induction of KA by BRAF inhibitors and procedures of esthetic dermatology. Finally, treatment strategies are presented with surgical excision as a first option, followed by other modalities, including intralesional chemotherapy, topical and systemic agents, lasers, cryotherapy, and photodynamic therapy.

CD1A-positive cells and HSP60 (HSPD1) levels in keratoacanthoma and squamous cell carcinoma

CD1a is involved in presentation to the immune system of lipid antigen derived from tumor cells with subsequent T cell activation. Hsp60 is a molecular chaperone implicated in carcinogenesis by, for instance, modulating the immune reaction against the tumor. We have previously postulated a synergism between CD1a and Hsp60 as a key factor in the activation of an effective antitumor immune response in squamous epithelia. Keratoacantomas (KAs) are benign tumors that however can transform into squamous cell carcinomas (SCCs), but the reasons for this malignization are unknown. In a previous study, we found that CD1a-positive cells are significantly more numerous in KA than in SCC. In this study, we analyzed a series of KAs and SCCs by immunohistochemistry for CD1a and Hsp60. Our results show that the levels of both are significantly lower in KA than in SCC and support the hypothesis that KA may evolve towards SCC if there is a failure of the local modulation of the antitumor immune response. The data also show that immunohistochemistry for CD1a and Hsp60 can be of help in differential diagnosis between KAs and well-differentiated forms of SCC.

Vitiligo: a review of some facts lesser known about depigmentation

Vitiligo is a disorder that causes the destruction of melanocytes. It has three important factors underlying this destruction. The depigmented skin has many aberrant functions such as a muted response to contact allergens, a phenomenon also seen in mice that depigment. The white skin of those with vitiligo does not form non-melanoma skin cancers although the white skin of albinos, which has a similar color as vitiligo, is highly susceptible to skin cancer.

Incidence of nonmelanoma skin cancer in a cohort of patients with vitiligo

BACKGROUND

Nonmelanoma skin cancer (NMSC) incidence in patients with vitiligo has not been studied.

OBJECTIVE

We sought to quantify the incidence of NMSC in patients with vitiligo.

METHODS

A cohort of 477 patients with vitiligo and no history of NMSC seen in an outpatient academic center between January 2001 and December 2006 was established. All charts for patients with vitiligo were reviewed for incident NMSC, and histopathology verified. Age-adjusted (2000 US Standard Million) incidence rates were calculated and compared to US rates.

RESULTS

Six patients with NMSC were identified; all were Caucasian (>61 years). Age-adjusted incidence rates were: basal cell carcinoma, male 1382/100,000; basal cell carcinoma, female 0; squamous cell carcinoma, male 465/100,000; squamous cell carcinoma, female 156/100,000. Except for basal cell carcinoma in females, all rates were higher than US rates but not statistically significant.

LIMITATIONS

Comparison incidence rates from the general patient population during the same time period were unavailable.

CONCLUSION

Health care providers should be aware of the possible risk of NMSC in Caucasian patients with vitiligo.

Porcine skin as a model system for studies of adverse effects of narrow-band UVB pulses on human skin

Ultraviolet (UV) radiation has been widely used in medicine, and in recent years there has been a growing interest in narrow-band UVB therapies, especially those employing pulses of the 308-nm line of XeCl excimer lasers. Comparative studies in several skin pathologies showed that narrow-band UVB was more effective than classical broad-band UVB radiation. Simultaneously, UVB is carcinogenic and there is a need for data to establish the risk associated with phototherapies involving irradiations of human skin with different doses of narrow- and broad-band UVA and/or UVB radiation. Relevant data are sparse predominantly due to a lack of suitable model systems for study of this phenomenon. Our comparative study of human and porcine skin responses to pulses of narrow-band UVB radiation demonstrated that for doses ranging from 5 to 10,000 mJ/cm(2) both skin types have similar susceptibility to UVB-induced breaking of nuclear DNA, indicating that pig skin might serve as good model for studies of sensitivity of human skin to UVB radiation.

Treatment of vitiligo with narrow-band ultraviolet B: advantages and disadvantages

BACKGROUND

Narrow-band ultraviolet B (NB-UVB) therapy for vitiligo is increasingly used in patients who are unresponsive to other forms of therapy.

OBJECTIVE

This study measures levels of patient and physician satisfaction and the associated advantages and disadvantages of NB-UVB.

METHODS

A retrospective chart review was conducted of the first 50 patients with vitiligo treated at the Photoderm Clinic in Ottawa, Ontario. Data were obtained from digital photographs and patient charts (n = 50).

RESULTS

Percent repigmentation of the face and body was very good compared with the hands and feet (poor = 0-or< 33%; good = 33-or< 66%; very good = >or= 66%). The physician and patients were satisfied with results achieved with NB-UVB therapy (very good [VG]: medical doctor [MD] 49% [95% CI 35-63], patient [Pt] 51% [95% CI 37-65]; good [G]: MD 24% [95% CI 12-36], Pt 22% [95% CI 10-34]).

CONCLUSION

NB-UVB therapy is an effective treatment for vitiligo (ie, VG, repigmentation >or= 66%) that leads to high levels of patient and physician treatment-related satisfaction. Although there are disadvantages to NB-UVB therapy, the advantages outweigh the drawbacks. An objective evaluation such as the Vitiligo Area Scoring Index (VASI) is necessary to validate these findings. Additional limitations include those inherent in retrospective study design.