Occupationally related tumors in tar refinery workers

Interventional treatment of keratoacanthoderma: a case report

This current case report describes a 56-year-old male patient with a skin mass on his lip that had been growing for 1 year. The pathological findings demonstrated that the epidermis was characterized by hyperkeratosis, hyperplasia and hypertrophy and was formed in the shape of a crater. The skin on both ends had developed into a ball-like growth that resembled a volcanic cone. There was invasive growth of heterotype squamous epithelium and a small number of inflammatory cells infiltrating the dermis. Immunohistochemistry demonstrated an increase in P16 (the focus, +) and the hot spot Ki-67 index. The diagnosis was of tumour-like hyperplasia, malignancy and moderate-to-severe dysplasia confirming that it was keratoacanthoma. The patient underwent surgical resection and was discharged from hospital, but the tumour returned. Paclitaxel and cisplatin were administered intraoperatively and bilateral lingual artery perfusion chemoembolization was undertaken six times. This procedure led to an excellent postoperative recovery and discharge from hospital. Tumour therapy was regarded as successful. The patient's medical history included acute lymphoblastic leukaemia L1 and long-term immunosuppressant use. After a 6-month period of follow-up, he died from systemic organ failure as a consequence of having too many ailments.

Syncarcinogenesis of natural UV radiation and polycyclic aromatic hydrocarbons in the development of squamous cell carcinomas of the skin?

Squamous cell carcinomas (SCC) of the skin can be induced by occupational exposures to polycyclic aromatic hydrocarbons (PAHs), as in tar and soot, or to UV radiation and can be recognized and compensated as occupational diseases. A possible syncarcinogenic effect of these exposures in the development of SCC in humans is under discussion. For the scientific validation of this question, a systematic literature search was conducted using the databases PubMed, Web of Science, and Scopus. Studies on individuals with SCC of the skin and their precursors as well as occupational, non-occupational, or therapeutic exposure to UV radiation and PAHs were selected. In addition, animal studies with exposure to UV radiation and PAHs were evaluated. After screening the abstracts of 510 identified studies, the full texts of 131 studies were reviewed. None of the epidemiological studies provided robust evidence for a syncarcinogenesis of PAHs and UV radiation in the development of SCC of the skin in humans. Nevertheless, as there are indications for a (super-)additive effect of UV radiation and PAH exposure from animal studies and mechanistic investigations, syncarcinogenesis seems possible. However, quantitative dose-response relationships are lacking which would allow comparison of the onset of an adverse effect between the different exposure levels.

Differences in the mitochondrial microsatellite instability of Keratoacanthoma and cutaneous squamous cell carcinoma

Keratoacanthoma (KA) is a common cutaneous neoplasm which often resembles typical squamous cell carcinoma (SCC) in both its clinical and historical presentation. Several studies have attempted to identify methods for distinguishing between KA and SCC, however, none of these have proven to play any obvious roles in these tumors. Given this we went on to evaluate mitochondrial microsatellite instability (mtMSI) in KA and SCC in an effort to understand these tumors better. DNA was isolated from paired normal and tumoral tissues donated by 57 KA patients and 43 SCC patients. MtMSI was then analyzed using eight microsatellite markers and was observed in 2 (3.5%) of the 57 KA patients and 8 (18.6%) of the 43 SCC patients, respectively. MtMSI was also shown to affect different locations depending on tumor type. In KA patients, mtMSI was detected at mitochondrial D514 D-loop and presented with (CA) n repeats, in contrast, all of the SCC patient experienced mtMSI at the D310 with (C)n repeats of the D-loop region. These differences in location were found to be significant, which may support the hypothesis that KA and SCC have different pathogenetic pathways. Our results also suggest that mtMSI may be a candidate for developing novel differential diagnostic methods for KA and SCC.

No Association between Merkel Cell Polymavirus Infection and Keratoacanthoma in Korean Patients

Objectives:

Keratoacanthoma (KA) is a relatively common benign tumor and resembles squamous cell carcinoma (SCC). The definitive cause of KA remains unclear, but trauma, ultraviolet light, chemical carcinogens, human papillomavirus, genetic factors, and immunocompromised status have been implicated as etiologic or triggering factors. Merkel cell polyomavirus (MCPyV) is suspected to cause the majority of cases of Merkel cell carcinoma (MCC). MCPyV-DNA was found significantly more frequently in MCC and only found in about one fourth of KAs. In a recent study, MCPyV was found in Korean patients with MCC. The aim of this study was to determine the presence of MCPyV in Korean patients with KA.

Methods:

Paraffin-embedded tissue samples were analyzed for the presence of MCPyV-DNA by polymerase chain reaction (PCR). A total of 105 KA samples were analyzed.

Results:

A study of MCPyV has not been reported about KA in Korean cases. In the present study the MCPyV was not detected with KA in the Korean patients.

Conclusions:

This supports that KA and MCPyV are not related to each other and MCVyP is not a major factor in the pathogenesis of KA.

Occupation and relative risk of cutaneous squamous cell carcinoma (cSCC): A 45-year follow-up study in 4 Nordic countries

BACKGROUND

The age-adjusted incidence of cutaneous squamous cell carcinoma (cSCC) in the Nordic countries has increased during the last 60 years, and the identification of occupational variation in the relative risk of cSCC may have preventive implications.

OBJECTIVE

We sought to describe variation in the relative risk of cSCC between occupational categories in Finland, Iceland, Norway, and Sweden.

METHODS

This is a historical prospective cohort study based on record linkages between census data for 12.9 million people and cancer registry data from 1961 to 2005. Standardized incidence ratios for cSCC were estimated for 53 occupational categories with the cSCC incidence rates for the national population of each country used as reference.

RESULTS

During follow-up, 87,619 incident cases of cSCC were reported to the national cancer registries. In all countries combined, significant increased standardized incidence ratios were observed among seamen, military personnel, public safety workers, technical workers, teachers, transport workers, physicians, dentists, nurses, other health workers, religious workers, clerical workers, administrators, and sale agents (standardized incidence ratios between 1.08 and 1.77).

LIMITATIONS

Information on occupation was based on 1 point in time only.

CONCLUSION

The occupational variation of the relative risk of cSCC might be associated with socioeconomic factors, and to some extent to occupational exposures.

Keratoacanthomas arising in association with prurigo nodules in pruritic, actinically damaged skin

BACKGROUND

There is no known association between the development of keratoacanthomas and prurigo nodules.

OBJECTIVE

We report a case series of 7 patients with a long-standing history of actinic damage, pruritus, and prurigo nodularis who developed widespread keratoacanthomas within the same affected area.

METHODS

This was a retrospective case series assessing the clinical characteristics of patients with multiple keratoacanthomas arising in association with prurigo nodules.

RESULTS

All 7 patients were elderly Caucasian women (mean age 79 ± 3.7 years) with actinically damaged skin and a long-standing history of widespread pruritus and prurigo nodules. All patients had histologically confirmed keratoacanthomas, or squamous cell carcinomas with the clinical appearance of a keratoacanthoma, that developed within the field of prurigo nodules. All 7 patients had a clinical response to acitretin with a decrease in the number of lesions. Four patients had an associated eczematous dermatitis and were also treated with cyclosporine with improvement in pruritus and prurigo nodules and no increase in keratoacanthomas.

LIMITATIONS

The retrospective design and small number of patients are limitations to this study.

CONCLUSION

Our case series represents a distinct subset of elderly individuals with extensive actinic damage who we believe are predisposed to developing both prurigo nodules and keratoacanthomas.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

Keratoacanthoma: facts and controversies

The keratoacanthoma and its variants are clinically and histologically heterogenous. Some consider the keratoacanthoma to be benign, whereas others classify it as a subtype of squamous cell carcinoma. The keratoacanthoma is generally treated rather than observed for spontaneous resolution. This hampers evaluation of the true natural history of lesions diagnosed as keratoacanthoma. In addition, studies have not found a reliable marker to differentiate keratoacanthoma from squamous cell carcinoma. It currently remains unclear how the keratoacanthoma relates to squamous cell carcinoma, and continued investigation is necessary.

Resveratrol enhances cell-mediated immune response to DMBA through TLR4 and prevents DMBA induced cutaneous carcinogenesis

Toll-like receptors (TLRs) activate signals that are critically involved in innate immune responses and that contribute to the initiation of adaptive immune responses. Resveratrol (trans-3,5,4-trihydroxystilbene), a polyphenol found in red grapes and in several other plant sources, is an effective chemopreventive agent in cutaneous chemical carcinogenesis. In this study, we investigated whether TLR4 was required for the chemopreventive action of resveratrol in DMBA skin carcinogenesis. For this purpose, mice with normal and deficient TLR4 function were compared when pretreated with resveratrol and then subjected to a DMBA-induced skin carcinogenesis protocol. There were fewer tumors/group (P < 0.001) in resveratrol treated TLR4 competent C3H/HeN mice than in TLR4 deficient C3H/HeJ mice. In addition, the size of tumors in C3H/HeN mice was reduced in vivo and their survival in vitro was inhibited by resveratrol to a significantly greater extent than in C3H/HeJ mice. Resveratrol inhibited angiogenesis to a much greater extent in the TLR4 competent mice than in TLR4 deficient mice. IFN-gamma and IL-12 levels were also increased in TLR4 competent mice compared to TLR4 deficient mice, and TLR4 competent C3H/HeN mice exhibited a greater increase in the cell-mediated immune response to DMBA. The results of this study indicate that TLR4 is an important mediator of resveratrol chemoprevention in DMBA skin tumorigenesis.

Skin tumors among employees of a tar refinery: the current data and their implications

OBJECTIVE

Skin tumors and their preliminary stages may be recognized and compensated as an occupational disease only after exposure to soot, raw paraffin, tar, anthracene, pitch or similar substances. The presented study was carried out in one of the world's largest tar refineries and special attention was paid to the dermatological long-term effects and today's relevance of tar-induced skin lesions.

METHODS

The data were generated by means of a standardized questionnaire based on occupational disease records and dermatological reports that have been carried out on a regular basis retrospectively. Among other things, the localization, the number and type of skin tumor, the date of diagnosis and the histological evaluation, where available, were taken into account.

RESULTS

In a longitudinal analysis from 1946 to 2002, a total of n = 618 employees were examined. Squamous cell carcinomas n = 393, basal cell carcinomas n = 298, keratoacanthomas n = 194 and melanomas n = 6 were diagnosed. Latency periods for keratoacanthomas (median 29.5 years) and squamous cell carcinomas (median 28.0 years) were almost identical and could possibly imply that the pathomechanisms for both types of skin tumor might be comparable. Of the persons diagnosed, the skin tumors were mainly localized in the head region (n = 1,662). A remarkable divergence in the localization and distribution of the lesions was found when compared to the general population, for example the relative susceptibility of the upper lip (n = 67) compared to the lower lip (n = 31) as well as the less sun-exposed forearms (n = 381) compared to the back of the hand (n = 331), being typically preferred sites of squamous cell carcinomas. Furthermore, a discrepancy between the distribution of premalignant nonmelanoma skin tumors and carcinomas on the back of the nose, which is more exposed to the sun (n = 56) and those in the nostrils (n = 89), which are less exposed to the sun, but are in the act of breathing more exposed to tar, could be found.

CONCLUSIONS

Tar-induced skin lesions are still of importance nowadays, which is reflected in the incidence of new cases and in the relapses of skin tumors. As a consequence, intensified measures are necessary, in the form of primary and secondary prevention. In view of the high incidence of malignant skin tumors in the general public, it is urgently necessary to take occupational hazards into consideration as well.

Keratoacanthoma observed

Conventional advice for managing suspected keratoacanthoma is total excision because of concern that the lesion may be a squamous cell carcinoma and histological differentiation of the two lesions is difficult. Only isolated cases have been published where lesions have been observed, with photographic documentation, to spontaneous resolution. Over 11 years (1992-2002) the author made a primary clinical diagnosis of solitary keratoacanthoma in 19 patients based upon the history and lesion appearance. Two thigh skin graft donor site lesions, and one on the nose and one on the lower lip were excised when there was concern about their growth pattern. A fifth patient was not content to be observed and had the lesion curetted by an oncologist. The remaining 14 patients had observed lesions photographed sequentially until resolution. The commonest single site affected was the hand (five cases). The mean age was 65 years (42-86 years). The mean duration of the lesion at presentation was 9 weeks (4-28 weeks), and the mean time to resolution from appearance was 27 weeks (12-64 weeks). Mean follow-up after resolution was 3 years 5 months (range 9 months-8 years). No recurrences occurred. No scar revisions were necessary. Claims that resolved keratoacanthomas leave poor quality scars that may need surgical revision, were not confirmed in this illustrated series which is the largest published to date. The principles of observational management are outlined and the natural history of the condition and patterns of spontaneous resolution described.

Environmental risk factors predisposing to the development of basal cell carcinoma

BACKGROUND

Basal cell carcinomas (BCCs) are the most common malignancies in white people. The incidence varies depending on the region of the world, with the highest rate of 1% to 2% per year noted in Australia. It is estimated that BCC incidence increases by 5% annually. An increasing incidence of BCC is in line with the changes in the living style and exposure to various environmental factors.

OBJECTIVE

To present the environmental factors that may influence the development of BCCs. The influence of ultraviolet radiation exposure alone and in connection with immunosuppression, smoking, occupational factors, as well as arsenic and ionizing radiation exposure, was described.

CONCLUSION

BCC is a very complex disease, with many factors influencing its development. Environmental factors are very important for the prevalence of BCC, and most of them can be avoided. The exposure to ultraviolet radiation is undoubtedly of great risk; therefore, the national campaigns against aggressive, seasonal sun exposure, especially in children and adolescents, as well as using sunscreens, are of great value in the fight against BCC development.

Keratoacanthoma developing in sites of previous trauma: a report of two cases and review of the literature

Keratoacanthoma is a common benign squamous neoplasm that only rarely progresses to metastatic carcinoma. The cause of keratoacanthoma is unclear; however, suspected causes include ultraviolet light, genetic factors, immunosuppression, chemical carcinogens, viruses, and trauma. Keratoacanthomas have been reported only rarely to arise in sites of previous trauma. We report 2 cases of keratoacanthomas arising shortly after episodes of cutaneous trauma and provide a review of the literature of similar cases previously reported. It is likely that an interaction exists between a variety of factors in the development of keratoacanthomas; however, it appears that a predilection exists for these lesions to arise in trauma sites.