The precursors of cutaneous squamous cell carcinoma

Early-life or lifetime sun exposure, sun reaction, and the risk of squamous cell carcinoma in an Asian population

BACKGROUND

It has been widely accepted that sun exposure is a risk factor of squamous cell carcinoma (SCC) among fair-skinned populations. However, sun exposure and sun reaction have not been explored in Asians and no gender-specific data were available.

METHOD

In a case-control study, 176 incident skin cancer cases were recruited from National Cheng-Kung University Medical Center from 1996 to 1999. Controls included 216 age-, gender-, and residency-matched subjects from the southwestern Taiwan. A questionnaire was administered to collect information on life style and other risk factors. Logistic regression analysis was performed to evaluate the association between sun exposure or sun reaction and the risk of SCC by gender.

RESULTS

Early-age (age 15 to 24) and lifetime sun exposure were significantly associated with increased risk of SCC in a dose-response pattern [odds ratio (OR) = 1.49-3.08, trend p = 0.009 and 0.0007, respectively]. After stratified by gender, the third tertile of early-age sun exposure was significantly associated with the SCC risk among men (OR = 3.08). The second and third tertiles of lifetime sun exposure was significantly associated with SCC risk among women (OR = 3.78 and 4.53, respectively). Skin reaction after 2-h sun exposure during childhood and adolescence was not significantly associated with the risk of SCC.

CONCLUSIONS

Lifetime sun exposure was more related to SCC risk in women, while early-age sun exposure was more relevant to men's SCC risk. This may be attributable to different lifestyle between men and women.

Imiquimod 5% cream monotherapy for cutaneous squamous cell carcinoma in situ (Bowen's disease): A randomized, double-blind, placebo-controlled trial

BACKGROUND

We conducted a double-blind, placebo-controlled, randomized trial to evaluate the preliminary efficacy and safety of imiquimod 5% cream treatment for cutaneous squamous cell carcinoma (SCC) in situ.

METHODS

In all, 31 patients with biopsy-proven cutaneous SCC in situ were randomly assigned to placebo (vehicle) (n = 16) or imiquimod 5% cream (n = 15) daily for 16 weeks. Patients were assessed at week 28 for the primary end point, resolution of cutaneous SCC in situ.

RESULTS

Of the 31 patients enrolled, 3 dropped out. Intention-to-treat analysis revealed 11 of the 15 patients (73%) in the imiquimod group achieved resolution of cutaneous SCC in situ, with no relapse during the 9-month follow-up period; none in the placebo group achieved resolution (P < .001). Imiquimod 5% cream was generally well tolerated and there were no serious adverse events.

LIMITATIONS

Topical imiquimod 5% cream has proven to be an effective treatment for cutaneous SCC in situ. However, studies to define the ideal dosing regimen and cost-effectiveness are required before it can be accepted as a recognized therapy.

CONCLUSIONS

In this controlled trial, patients with cutaneous SCC in situ receiving topical imiquimod 5% cream as monotherapy experienced a high degree of clinical benefit compared with placebo.

Digital syndactylization for the treatment of interdigital squamous cell carcinoma in situ (Bowen disease)

Bowen disease, or squamous cell carcinoma in situ, has been described as a premalignant intraepidermal lesion of the skin. Although more frequently occurring on limbs, interdigital presentation of squamous cell carcinoma in situ in the foot has been rarely reported, likely because of undetected development. Excision has been recommended as the treatment of choice; however, removal of these lesions from intertriginous skin may present few options for skin closure. Interdigital syndactylization may be an acceptable option for the treatment of interdigital manifestations of Bowen disease. The authors present a case of interdigital squamous cell carcinoma in situ successfully treated with excision and digital syndactylization. At the 2-year follow-up, there was no recurrence and no digital deformities.

Non-melanotic skin tumors of the upper extremity

Most non-melanotic skin cancers involving the upper extremities are squamous cell and basal cell carcinomas. Ultraviolet sun light, fair complexion, and advancing age are important risk factors. Because of their high prevalence, the hand surgeon must be familiar with the diagnosis and clinical management of non-melanotic skin tumors. Early detection ultimately decreases the morbidity associated with the locally destructive nature of these tumors. Following diagnosis, the appropriate steps for management include wide surgical excision with pathologic conformation of normal margins and lymph node dissection for clinically positive nodes

Disseminated squamous cell carcinoma of the skin

BACKGROUND

Squamous cell carcinoma (SCC) accounts for a large proportion of nonmelanoma skin cancers. It may appear mainly on the skin and the mucous membranes; however, it may also appear on any part of the body. The tumor originates from atypical keratinocytes. This tumor, which can be locally destructive, has a metastasis rate of 5% to 10%.

OBJECTIVE

To present a patient with disseminated primary SCC of the skin.

METHODS

In this report, we present a unique case of disseminated SCC that is thought to be primary. As far as we know, the patient neither had any syndrome or a disease predisposing to SCC nor was exposed to toxic substances or ionized radiation. The disease progressed in a very short period. To our knowledge, there has not so far been a case of disseminated primary SCC. The patient was inoperable when he presented to our clinic.

RESULTS

Chemotherapy was instituted in the Department of Medical Oncology; unfortunately, the patient died while on the therapy.

CONCLUSION

An original case of disseminated SCC of the skin is presented.

Proliferative actinic keratosis: three representative cases

OBJECTIVE

This article describes a new subtype of actinic keratosis that exhibits proliferative characteristics both histologically and clinically. We describe three representative cases occuring in the presence of infiltrative squamous cell carcinoma (SCC) and/or basal cell carcinoma (BCC).

METHODS

Histories of each lesion in the three cases discussed were obtained. The lesions were removed by Mohs micrographic surgery. Permanent sections, stained with hematoxylin and eosin, were examined and studied under light microscopy.

RESULTS

All three lesions had failed conventional treatment with liquid nitrogen and/or 5-fluorouracil (5-FU). Histologic examination of the lesions revealed sheets of dysplastic cells growing along the basal layer of the epidermis and migrating down hair follicles and sweat ducts. An associated infiltrative SCC and/or BCC was found in each case.

CONCLUSIONS

Proliferative actinic keratosis is resistant to standard therapies because of deep migration of abnormal cells along hair follicles and sweat ducts. It has a strong propensity to develop infiltrative SCC and may occur concomitantly with BCC.

Squamous cell cancer: a practical approach

Cutaneous squamous cell carcinoma (SCC) is the second most common form of skin cancer and is treated frequently by dermatologists. For many years, the level of knowledge regarding treatment of SCC has taken a backseat to the treatment of basal cell carcinoma and malignant melanoma. As dermatologists become more surgically proficient and assume a leading role in the surgical care for cutaneous carcinoma, a thorough knowledge of the appropriate management of SCC is of paramount importance. In particular, it is essential to recognize that, unlike basal cell carcinoma, certain SCC have a significant metastatic potential and require more comprehensive care. This review targets the etiology, pathogenesis, clinical presentation, histopathology, and treatment of SCC. Particular attention is focused on providing appropriate care for SCC and recognizing and arranging appropriate management for high risk SCC.

Cutaneous manifestations of chronic arsenicism: review of seventeen cases

BACKGROUND

Cutaneous complications arising from exposure to Chinese proprietary medicines known to contain inorganic arsenic have been rarely reported.

OBJECTIVE

Our purpose was to study the nature, incidence, and sequelae of patients with chronic arsenicism and to review the literature on arsenic-induced skin diseases.

METHODS

Case records of patients with cutaneous lesions related to chronic arsenicism seen from January 1990 to December 1996 were reviewed. Patients were interviewed and a complete skin and systemic examination was performed. Data on demography, history of arsenic ingestion, and type and distribution of skin lesions and visceral malignancy were collated.

RESULTS

Seventeen Chinese patients (11 men, six women) were identified; their mean age was 64.5 years. Fourteen patients (82%) had exposure to Chinese proprietary medicines known to contain inorganic arsenic, and three had environmental arsenic exposure from well water. The mean age of these 14 patients was 17.6 years; mean duration of arsenic intake was 6.4 years. Seventeen patients had Bowen's disease; of these, 70% had 2 to 10 lesions. Of the 17 patients with arsenical keratoses on the palms, 76% had 2 to 10 lesions. Of the 14 patients (82%) with plantar arsenical keratoses, 64% had 11 to more than 50 lesions. Eleven patients (65%) had macular hypopigmentation. Seven patients (41%) had 11 squamous cell carcinomas (SCCs); three of the seven had more than one lesion. Fifty-five percent of SCCs arose from preexisting keratotic lesions (n = 4) or Bowen's disease (n = 2), and 45% arose de novo. One patient each (6%) had multiple basal cell carcinomas, laryngeal carcinoma, and metastatic SCC. The latency periods for the development of arsenical keratoses, Bowen's disease, and SCC were 28, 39, and 41 years, respectively. Patients with SCC were significantly older at the start of arsenic exposure and had significantly more palmar arsenical keratoses than those without SCC.

CONCLUSION

Exposure to Chinese proprietary medicines containing inorganic arsenic poses a risk for the development of cutaneous and systemic malignancies. Long-term follow-up is necessary for tumor detection because of long latency periods. Surveillance programs are important to restrict the sale of Chinese proprietary medicines that may contain inorganic arsenic.

Actinic keratoses. Differential diagnosis and treatment

Actinic keratoses are extremely common premalignant keratinocytic neoplastic lesions that develop primarily in fair-complexioned individuals during midlife or beyond. Genetic, occupational and other environmental factors predispose to the development of these lesions. Without treatment, a significant number may progress to fully developed neoplasms, especially squamous cell carcinoma, over a period of 20 to 50 years. The multistep theory of carcinogenesis is helpful in understanding the pathogenesis and progression of this important and highly prevalent lesion.

Premalignant keratinocytic neoplasms

Premalignant keratinocytic keratoses are common, especially in pale-complected persons in whom they appear most often as an actinic keratosis. Although the actinic keratosis has a very low malignant potential, arsenic, tar, thermal, scar, reactional, and radiation keratoses may be more clinically aggressive. This article discusses these premalignant keratinocytic neoplasms.

Feline cutaneous and subcutaneous neoplasms

This article contains practical information about the more common feline skin tumors and an update on recent treatments. The tumor type, gross appearance, clinical behavior, prognosis, and treatment are provided.

Multiple risk factors associated with arsenic-induced skin cancer: effects of chronic liver disease and malnutritional status

In order to evaluate the prevalence and multiple risk factors of arsenic-induced skin cancer among residents in Taiwanese villages in which chronic arseniasis is hyperendemic, a total of 1571 subjects aged 30 or more years were recruited between September 1988 and March 1989. All of them were interviewed personally by a public health nurse using a structured questionnaire, and 1081 interviewed study subjects, including 468 men and 613 women, participated in physical examination, giving a participation rate of 68.8%. The overall prevalence of skin cancer was as high as 6.1%, showing an increase with age in both men and women. There was a significant dose-response relation between skin cancer prevalence and chronic arsenic exposure as indexed by duration of residence in the endemic area, duration of consumption of high-arsenic artesian well water, average arsenic exposure in parts per million (p.p.m.) and cumulative arsenic exposure in p.p.m.-years. Chronic carriers of hepatitis B surface antigen with liver dysfunction had an increased prevalence of skin cancer. Undernourishment, indexed by a high consumption of dried sweet potato as a staple food, was also significantly associated with an increased prevalence of arsenic-induced skin cancer. All these risk factors remained statistically significant in the multiple logistic regression analysis. Consistent with animal experiments, the findings imply that liver function and nutritional status may affect the metabolism of inorganic arsenic and the development of subsequent skin cancers.

Proliferative actinic keratosis

BACKGROUND

Solar/actinic keratoses (AKS) are premalignant lesions, usually less than 1 cm in diameter, that appear on chronically sun-damaged skin.

METHODS

We describe four patients with a form of AK that enlarged and recurred despite standard treatment. Histologic examination revealed a single and multilayered sheet of anaplastic cells along the undersurface of the epidermis extending down hair follicles and present over a large area.

RESULTS

Three of the patients developed either a squamous cell carcinoma (SCC) or basal cell carcinoma (BCC) within the area encompassed by the AK.

CONCLUSIONS

These cases represent an insidious, proliferative form of AK with an increased tendency to develop into skin cancer.

Multicentric squamous cell carcinoma in situ resembling Bowen's disease in cats

Multicentric squamous cell carcinoma in situ was studied in 12 cats (eight castrated males and four spayed females). The neoplasms occurred in middle-aged to old (mean age = 12 years) mixed-breed cats with a variety of hair-coat colors. The lesions were found in haired pigmented regions of the skin, including the trunk, limbs, feet, head, and neck, and were unrelated to exposure to sunlight. Lesions occurred at multiple sites in nine cats and at solitary sites in three cats and were from 0.5 cm to 3.0 cm in diameter, irregular, slightly elevated, plaque-like or papillated, and partially alopecic. Histologically, the lesions consisted of sharply demarcated regions of neoplastic, keratinocytic infiltration of the epidermal and follicular infundibular epithelium. Neoplastic cells were confined to the epithelium without frank invasion of the dermis. Two histologic subclasses of multicentric squamous cell carcinoma in situ were identified, the irregular nonhyperkeratotic type and the verrucous hyperkeratotic type. Three cats also had invasive squamous cell carcinoma adjacent to lesions characteristic of multicentric squamous cell carcinoma in situ. Grossly, these were solitary 2.0-4.0 cm-diameter firm, crusted, crateriform cutaneous masses. During follow-up periods of 4 to 20 months (mean follow-up period = 11 months), neoplasms did not recur locally after surgical excision; however, similar lesions developed at new sites in four cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Bowenoid changes in Kaposi's sarcoma

BACKGROUND

Previous reports have documented the coexistence of multiple infectious organisms or Kaposi's sarcoma within the same biopsy specimens of mucocutaneous lesions in human immunodeficiency virus- (HIV) infected patients.

OBJECTIVE

A 31-year-old black man with the acquired immunodeficiency syndrome (AIDS) who had Bowenoid changes and Kaposi's sarcoma within the same cutaneous lesion is described.

METHODS

Microbiologic cultures, microscopic examination, and polymerase chain reaction were performed on a lesional skin biopsy specimen to evaluate for infectious organisms, histopathology, and the presence of human papillomavirus (HPV) deoxyribonucleic acid (DNA), respectively.

RESULTS

Bacteria, fungi, and mycobacteria were not detected with special stains and cultures. The histologic findings were consistent with Bowen's disease in the epidermis and patch stage Kaposi's sarcoma in the dermis. There was no polymerase chain reaction product generated from the HPV-specific primers in two individual polymerase chain reaction assays.

CONCLUSION

The possibility that coexisting infectious or neoplastic disorders, or both, may be present within a single mucocutaneous lesion should always be considered when evaluating a lesion from an HIV seropositive individual.

Mutant p53 expression in solar keratosis: an immunohistochemical study

Thirty-eight solar keratoses from 32 patients were studied for expression of mutant p53 protein by an immunohistochemical technique. Twenty-eight of the 38 solar keratoses (73.7%) showed positive and variable nuclear labelling, whereas 10 specimens were immunonegative. The nuclear immunopositivity which was seen in all variants was mostly diffuse in distribution. The adjacent "normal" epidermis of 8 keratoses showed positive mutant p53 labelling. Eight of the keratoses were associated with invasive squamous cell carcinoma of which only two were immunopositive. Cytoplasmic labelling was never a feature. The study demonstrates that mutant p53 protein is commonly expressed in all variants of solar keratosis and that its expression correlates with atypical keratinocyte proliferation. It is proposed that the demonstration of mutant p53 in the adjacent normal epidermis may be a potential marker of early neoplastic transformation.

Arsenic-induced skin toxicity

We reviewed available literature on the effects of inorganic arsenic on the skin to determine the potential hazards and to collate information regarding dosage and exposure to the incidence of skin cancer. Arsenic intake may result from occupational or medicinal exposure, or from drinking well water in areas with high arsenic levels in the soil. Arsenic causes a variety of benign skin lesions including hyperpigmentation and hyperkeratosis. Some hyperkeratotic lesions and squamous cell carcinomas in situ may progress to invasive carcinoma; other invasive squamous cell carcinomas will develop de novo. These cutaneous squamous cancers may metastasize; mortality is low, but has been reported. Locally invasive but non-metastasizing basal cell carcinomas may arise as well. These lesions occur in a characteristic pattern of distribution and are usually multiple. Observers reporting medicinally administered arsenic have described dose-response relationships between the amount of arsenic ingested and the frequency of various skin lesions. For arsenic found in drinking water, however, there is more controversy regarding the doses and exposure times necessary for cutaneous toxicity.

The benign acanthomas

An important, yet neglected, problem in dermatopathology, is the evaluation of the benign acanthomas, the benign tumors of epidermal keratinocytes. The benign acanthomas may be simulated by lesions which are not benign (e.g. actinic keratosis), not tumors (e.g. normal plantar skin), or are not epidermal (e.g. dermatofibroma). In addition to normal (epidermoid) keratinization (e.g., seborrheic keratosis and related conditions), the variants of the benign acanthomas show a wide range of aberrant keratinization, including epidermolytic hyperkeratosis (epidermolytic acanthoma), dyskeratosis (warty dyskeratoma), acantholysis (acantholytic acanthoma), cornoid lamellation (porokeratosis), lichenoid hyperplasia (lichen planus-like keratosis), and absence of keratinization (clear cell acanthoma).

Adnexal metaplasia in carcinoma in situ of the skin

Two cases of epidermoid carcinoma in situ of the skin, one with mucinous metaplasia and the other with sebaceous metaplasia, are reported. These unique cases suggest a spectrum of differentiation possible by neoplastic epidermal keratinocytes, which may help in the understanding of the histogenesis of certain skin neoplasms.