Nevoid keratosis of the nipple.
A patient with nevoid keratosis of the nipple is described. The clinical features, histology, therapy, and prognosis are discussed.
Adult↗
SEARCH · Search PubMed
Results for “KERATOSIS”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Loss of heterozygosity in actinic keratosis, squamous cell carcinoma and sun-exposed normal-appearing skin in Japanese: difference between Japanese and Caucasians.
Actinic keratosis (AK) has been considered to be a precursor of squamous cell carcinoma (SCC). However, based on epidemiological and molecular studies, it has become questionable to regard AK as a precancerous lesion. We analyzed 37 AKs and 14 sporadic SCCs using six microsatellite markers in order to elucidate if any genetic instability or loss of heterozygosity (LOH) was implicated in tumorigenesis and progression of non-melanocytic skin tumor. Microsatellite instability (MSI) was not found in any of the AKs or SCCs indicating that genetic instability has little implication in the tumorigenesis of sporadic non-melanocytic skin tumor. LOH was found in seven of 37 lesions of AK, but in only one of 14 lesions of SCC. The significantly lower frequency of LOH than that previously reported in Caucasians suggested that the molecular pathogenesis of AKs and SCCs might be different between Japanese and Caucasians. The higher frequency of LOH in AKs than in SCCs in the present study supported the previous epidemiological and molecular studies that AK was not likely to proceed to SCC. LOH was also demonstrated in histologically normal-appearing skin in three cases suggesting that genetic alteration occurs before histological change appears in the sun-exposed skin.
Aged↗
Detection and sequences of human papillomavirus DNA in nongenital seborrhoeic keratosis of immunopotent individuals.
BACKGROUND: The etiology of seborrhoeic keratosis (SK) is unknown. Its clinical and histopathological similarities to verrucae vulgaris and condyloma acuminatum prompted us to examine whether human papillomavirus (HPV) is present in SK lesions. In the present study, HPVs were frequently detected from genital lesions or hair follicle in immunocompromised host. OBJECTIVE: We analyzed 104 nongenital SK specimens diagnosed by clinical and histopathological examinations for HPV DNA in immunopotent individuals. METHOD: We analyzed SK specimens for HPV DNA using in situ hybridization (ISH), polymerase chain reaction (PCR), Southern blot hybridization, and sequencing of viral DNA of PCR-amplified fragments. And we also examined virion, which is the capsid protein of HPV in ISH-positive specimens by immunochemical examination. We identified eight mucosal and two cutaneous type HPVs. RESULT: ISH revealed that 30 of 104 (28.8%) SK samples contained HPV DNA. All ISH-positive specimens were demonstrated virion in the nuclei of the epidermal keratinocytes. PCR analysis showed that 87 (83.7%) samples contained HPV-18, 81 (77.9%) HPV-6, and 73 (70.2%) contained both HPV-18 and -6. The incidence of HPV-1 (7.7%) and HPV-2 (14.4%) was relatively low. All 20 normal controls were negative for HPV DNA by ISH but seven were positive by PCR sequencing. CONCLUSION: Our results suggest that HPV, possibly coinfection with HPV-6 and -18 and unknown type(s) of HPV, plays an important role in the pathogenesis of SK.
Adult↗
Prevalence of actinic keratosis in Japan.
Most of the epidemiological studies on skin cancer that have been conducted to date have addressed the incidence in light-skinned Caucasians. To determine the prevalence rate of skin cancer and actinic keratosis (AK) on sun-exposed body sites of Japanese in Japan, we examined the skin of 4736 people during health examinations. The study was undertaken in Kasai City, Japan, which had a population of 52,837 in 1992, where participants in a regional health examination were seen by dermatologists. The final diagnosis was made histopathologically. Participants were also interviewed by means of a questionnaire. A total of 36 cases of AK and two of basal cell carcinoma were identified, to give a prevalence of 413.4 per 100,000 for AK. The prevalence among outdoor workers was significantly higher than that of indoor workers. Furthermore, when the participants were classified into three Japanese skin types, the prevalence of AK among people of skin Type I, who are sensitive to UV irradiation, was significantly higher than that among people of skin Types II and III, who are less sensitive.
Adult↗
Apoptosis in the areas of squamous differentiation of irritated seborrheic keratosis.
Seborrheic keratosis (SK) consists of a localized proliferation of basaloid keratinocytes, often accompanied by hyperkeratosis and hyperpigmentation. In irritated SK, these features are associated with areas of squamous differentiation with larger keratinocytes and squamous cell eddies. This work is concerned with the evaluation of apoptosis, as demonstrated by the TUNEL method, in the different varieties of SK. Apoptosis was highly expressed in the areas of squamous differentiation of irritated SK, but only mildly increased in the other varieties of SK. These data support the hypothesis that apoptosis has a role in the squamous differentiation of irritated SK. In consideration also of previous data showing that irritated SK is associated with downregulation of EGF-R expression and 125I-EGF binding, we postulate that the morphologic features of irritated SK could correspond to an involution phase of the disease, characterized by altered cell balance with inadequate cell renewal and increased cell loss.
Adult↗
Basal cell carcinoma with tricholemmal (at the lower portion) differentiation within seborrheic keratosis.
BACKGROUND: Recent genetic investigations support the idea that basal cell carcinoma (BCC) is trichoblastic carcinoma. However, it is generally thought that clear cell basal cell carcinoma is a result of degeneration rather than tricholemmal differentiation. METHODS: We report a case of BCC, with clear cell components, that developed within seborrheic keratosis, with histopathological and immunohistochemical findings. RESULTS: The clear cell components in the present case showed the following four characteristics: (i) at the periphery of the aggregations, columnar clear cells were aligned in a palisade along a well-defined basement membrane; (ii) the nuclei of the columnar clear cells were at the pole opposite the basement membrane; (iii) the clear cells contained glycogen; (iv) in the aggregations with clear cell components, there was diffuse positive staining for cytokeratin 7 (CK7) (OV/TLR/30), but only the inner region stained positive for CK17. These four characteristics are comparable to those of the lower portion of normal outer root sheath. In addition, the BCC in the present case was partly composed of squamous cells that contained glycogen and were selectively positive for CK17 - features similar to those of squamous cells in normal outer root sheath. CONCLUSIONS: Some clear cell BCCs are simply the result of degenerative change, but other clear cell BCCs may be the result of tricholemmal (at the lower portion) differentiation.
Biomarkers, Tumor↗
Expression of matrix metalloproteinase-1, -2 and -3 in squamous cell carcinoma and actinic keratosis.
Matrix metalloproteinase (MMP) plays an important role in extracellular matrix degradation associated with cancer invasion. An expression of MMP-1 (interstitial collagenase), MMP-2 (72-kDa type IV collagenase) and MMP-3 (stromelysin-1) was investigated in squamous cell carcinoma (SCC) and its precancerous condition, actinic keratosis (AK), using in situ hybridization techniques. MMP-1 mRNA was detected in tumour cells and/or in stromal cells in all cases of SCC, four of six AKs adjacent to SCC and four of 16 AKs. MMP-2 and MMP-3 mRNAs were detected in SCC but not in AK. The expression of MMP-3 correlated to that of MMP-1 (P = 0.03) localized at the tumour mass and stroma of the invasive area, while MMP-2 mRNA was detected widely throughout the stroma independent of MMP-1 expression. Our results indicated that the expression of MMP-1, -2 and -3 showed different localization patterns, suggesting a unique role of each MMP in tumour progression. Moreover, MMP-1 expression could be an early event in the development of SCC, and AK demonstrating MMP-1 mRNA, might be in a more advanced dysplastic state, progressing to SCC.
Carcinoma, Squamous Cell↗
Porphyrin formation in actinic keratosis and basal cell carcinoma after topical application of methyl 5-aminolevulinate.
Photodynamic therapy using topical methyl 5-aminolevulinate (MAL) is a new treatment modality for basal cell carcinoma (BCC) and actinic keratosis (AK). MAL induces endogenous porphyrins, which act as photosensitizers. Pharmacokinetic studies of the porphyrin-inducing effect of MAL creams (Metvix) applied in different concentrations (16-160 mg/g) and application times are presented. Surface fluorescence measurements were used to monitor porphyrin accumulation in 18 superficial BCCs and 32 AKs. For both lesion types, the fluorescence increased during the first 13 of 28 hours of continuous MAL application. A 20-fold site-to-site variation was observed, and there were no significant MAL concentration dependencies. The selectivity between lesions and normal skin was 10-fold during the first hours and decreased throughout the application time. Fluorescence microscopy images of tissue sections from 32 nodular BCCs were analyzed to calculate the porphyrin content in tumor tissue as a function of depth. Significant correlation to MAL concentration was seen within the tumors treated for 3 hours. Increase to 18-hour MAL application enhanced the fluorescence levels in superficial tumor layers, but not in deep layers. In conclusion, application of the 160 mg/g cream for 3 hours gave advantageous porphyrin distributions for all types of lesions.
Administration, Topical↗
Ultraviolet light downregulates CD95 ligand and TRAIL receptor expression facilitating actinic keratosis and squamous cell carcinoma formation.
Long-term ultraviolet light exposure of human skin epidermis in Caucasians is associated with an increased risk for the development of melanoma and nonmelanoma skin cancers. Ultraviolet radiation not only induces DNA damage in epidermal cells, it also interferes with skin homeostasis, which is maintained by a unique distribution pattern of apoptosis-inducing and apoptosis-preventing molecules. We demonstrate that, beside CD95 ligand, TRAIL and TRAIL receptors also function as important sensors in the human epidermis preserving skin integrity and preventing cell transformation. Ultraviolet irradiation extensively changes the expression pattern of some of these molecules, diminishing their sensor function. In particular, CD95 ligand and to a somewhat lesser extent TRAIL receptors are downregulated upon ultraviolet light exposure. CD95 ligand downregulation is not due to protein degradation as in situ hybridization experiments strongly support a transcriptional regulation. The downregulation of these molecules with sensor function increases the risk that aberrant cells are less efficiently eliminated. This concept is supported by the fact that the expression of these molecules is also low or absent in actinic keratosis, a precancerous state that has developed as the consequence of long-term ultraviolet exposure. Progression to invasive neoplasms is then accompanied by an upregulation of CD95 ligand and a downregulation of CD95 and of the TRAIL receptors. The high expression of CD95 ligand, TRAIL, and FLIP in squamous cell carcinoma may then contribute to the immune escape of the tumor, whereas the lack of expression of CD95 and TRAIL receptors prevents autolysis of the tumor.
Adult↗
Actinic keratosis: epidemiology and progression to squamous cell carcinoma.
Actinic keratoses are a common problem in the population, and one of the most common conditions treated by dermatologists. Risk factors for the development of actinic keratosis are those associated with increased sun exposure and increased susceptibility to sun exposure such as low latitude, working outdoors, light skin, and history of sunburn. The role of the immune system is clear from the frequency of actinic keratoses in transplant patients. There is strong evidence that actinic keratoses can progress to squamous cell carcinoma, underscoring the need to identify and treat patients at risk.
Aged↗
Summary of actinic keratosis studies with imiquimod 5% cream.
Imiquimod is being investigated as a therapeutic option for the management of actinic keratosis. Three recent clinical trials have demonstrated a reasonable efficacy rate and high safety profile. 'Cycle' therapy may improve the safety profile while maintaining efficacy. 'Field' treatment with imiquimod may uncover and treat 'subclinical' actinic keratoses, which in turn may potentially result in fewer recurrences. Longer follow-up studies are required to investigate this possibility.
Adjuvants, Immunologic↗
From actinic keratosis to squamous cell carcinoma.
The development of actinic keratosis (AK) and squamous cell carcinoma (SCC) is the result of a complex sequence of events initiated by exposure to ultraviolet (UV) light. The application of sunscreens prior to sun exposure has been reported to reduce the incidence of AK. The initial damage takes place in the DNA and most of the UV-induced lesions in the DNA are repaired. However, mutations may occur as a result of base mispairing of the cell and its DNA replicate before the DNA lesion is repaired. The genes involved in the repair process are also potential UV targets. Mutations in the tumour suppressor gene p53 are a common feature of AK and SCC. The hairless mouse is the best available animal model, in which lesions resembling human AK (papillomas), keratoacanthomas and SCCs may be induced. This model of multistage carcinogenesis offers an excellent tool for mechanistic studies. The relative efficacy of UV wavelengths (action spectrum) that induce SCC has been determined using the hairless mouse as a model. The action spectrum has been extrapolated to humans skin and is recognised worldwide.
Animals↗
Role of endothelin-1 in hyperpigmentation in seborrhoeic keratosis.
Seborrhoeic keratosis (SK) is a benign epidermal tumour with a varying degree of pigmentation. We have recently demonstrated that endothelin-1 (ET-1) is a strong keratinocyte-derived mitogen and melanogen for human melanocytes in UVB-induced melanosis. To clarify the role of ET-1 in hyperpigmentation in SK, we have used immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to see whether the production of ET-1 is accentuated in SK. Immunohistochemical analysis in SK (n = 7; acanthotic and deeply pigmented types) revealed marked immunostaining with anti-ET-1 in almost all basaloid and basal cells as compared with definite staining confined to basal cells in the perilesional normal controls. In parallel, RT-PCR of ET-1 mRNA demonstrated accentuated expression of ET-1 transcript in SK (n = 4) in comparison with that in the perilesional normal controls, accompanied by a similarly accentuated expression of tyrosinase mRNA. These findings suggest that ET-1 plays a part in the hyperpigmentation seen in SK.
Adult↗
Linear melanonychia due to subungual keratosis of the nail bed: a report of two cases.
Longitudinal melanonychia displaying features of keratinized acanthoma is described in two patients. In both cases, a pigmented band consisting of a subungual keratinized epithelial ridge originated in the nail bed. We have been able to show, using the clinical and histological findings, that the origin of the pigment is linked to its synthesis within the acanthoma of the nail bed. These lesions are reminiscent of pigmented seborrhoeic keratosis. The horny cysts are replaced, because of the special physiological longitudinal arrangement of the ridges in the nail bed, by a single, prominent, longitudinal, keratinized and pigmented mass.
Aged↗
Keratosis follicularis squamosa (Dohi): a follicular keratotic disorder well known in Japan.
Keratosis follicularis squamosa (KFS) is a keratinizing disorder, which is well recognized in Japan but rarely reported in other countries. KFS is characterized by asymptomatic small scaly patches with a follicular plug that is scattered on the trunk and thighs. It is easily diagnosed by its characteristic appearance that was originally described in Japanese as "lotus leaves on the water". We report a typical case of KFS and review the mainly Japanese literature. We conclude that KFS is a distinct clinical entity of unknown origin. World-wide recognition of this disease should further clarify the prevalence and pathogenesis of this skin condition.
Adult↗
The mechanism of hyperpigmentation in seborrhoeic keratosis involves the high expression of endothelin-converting enzyme-1alpha and TNF-alpha, which stimulate secretion of endothelin 1.
BACKGROUND: Seborrhoeic keratosis (SK) is a benign epidermal tumour with increased pigmentation. We have recently demonstrated that increased secretion of endothelin (ET)-1, a strong keratinocyte-derived mitogen and melanogen for human melanocytes, is intrinsically involved in the hyperpigmentation mechanism of SK. OBJECTIVES: To examine whether the increased ET secretion results from cytokines that induce ET production and/or from differences in the processing of ET that lead to its final active, secreted form. METHODS: We used immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to determine whether ET-inducing enzymes and/or cytokines are also highly expressed in SK. RESULTS: RT-PCR of mRNAs encoding interleukin (IL)-1alpha, tumour necrosis factor (TNF)-alpha and endothelin-converting enzyme (ECE)-1alpha demonstrated that there is an increased expression of TNF-alpha and ECE-1alpha mRNAs in SK, whereas the IL-1alpha transcript is rather downregulated in SK compared with that in perilesional normal epidermis. In parallel, immunohistochemical analysis of SK revealed marked immunostaining for TNF-alpha in basaloid cells at lower levels of the epidermis and in basal cells, and for ECE-1alpha in most basaloid and basal cells in comparison with their weak staining throughout the epidermis in perilesional normal controls. In contrast, immunostaining for IL-1alpha was almost negative in SK relative to distinctive staining throughout the epidermis in the perilesional normal controls. CONCLUSIONS: These findings suggest that the increased secretion of ET-1 leading to enhanced pigmentation in SK results from the co-ordinated increased expression of TNF-alpha and ECE-1alpha.
Cell Culture Techniques↗
Lamin expression in normal human skin, actinic keratosis, squamous cell carcinoma and basal cell carcinoma.
BACKGROUND: Aberrant expression patterns of nuclear lamins have been described in various types of cancer depending on the subtype of cancer, its aggressiveness, proliferative capacity and degree of differentiation. In general, the expression of A-type lamins (lamins A and C) has been correlated with a non-proliferating, differentiated state of cells and tissues. OBJECTIVES: To establish and compare the expression patterns of lamins in normal human skin, actinic keratosis (AK), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). METHODS: Expression patterns of the individual lamin subtypes were studied immunohistochemically. The proliferation capacity of the tumour cells was detected using a specific antibody to Ki-67, and was related to the A-type lamin expression patterns. RESULTS: In normal skin, lamin A was expressed in the suprabasal cell compartment of the epidermis, whereas the basal cells were mostly unstained. BCCs and SCCs stained positive in most cells, while the epidermis overlying BCC and SCC and the epidermis in AK stained homogeneously and strongly in the basal cells in addition to the suprabasal cells. Lamin C was expressed in some basal cells of normal epidermis while the suprabasal cells stained strongly positive. Both BCCs and SCCs stained strongly positive for lamin C, with the difference that in BCC the staining was predominantly present in nucleolar structures with occasional staining of the nuclear envelope. The epidermis overlying SCC showed strong positivity in the lamina of virtually all cells. The expression of lamin C in the basal cells of AK resembled the expression pattern seen in the epidermis overlying BCC, i.e. a nucleolar staining next to nuclear envelope staining. Lamin B1 and B2 were found in virtually all cells in normal epidermis, AK, BCC, SCC and the epidermis overlying cancer. The percentage of Ki-67-expressing cells was highest in BCC (45%), and gradually decreased via epidermis overlying BCC, AK, SCC, and epidermis overlying SCC, to normal skin (11%). Simultaneous expression of A-type lamins and Ki-67 occurred in approximately 50% of the proliferating (Ki-67 positive) cells in BCC and SCC. CONCLUSIONS: Significant changes occur in the expression patterns of A-type lamins in both premalignant and malignant lesions of the skin. The profound overlap of lamin A and Ki-67 staining patterns indicates that the proliferating tumour cells may obtain a certain degree of differentiation. Finally, lamin A expression in the basal cell layer of the apparently normal epidermis overlying BCC may suggest its involvement in the primary process.
Basal Cell Carcinoma↗
Comparison of the microvasculature of basal cell carcinoma and actinic keratosis using intravital microscopy and immunohistochemistry.
BACKGROUND: Angiogenesis is a prerequisite for growth of invasive tumours. We hypothesized that angiogenesis would be present in invasive basal cell carcinoma (BCC) but not in a noninvasive tumour such as actinic keratosis (AK). OBJECTIVES: To investigate both types of tumour for evidence of angiogenesis. METHODS: Patients with BCC or AK underwent intravital videocapillaroscopy. Three regions were examined: the tumour, perilesional skin and a control site. Microvessel width, area fraction and length density were determined from capillaroscopy images. Biopsies were stained for CD34 and a microvessel count was performed. RESULTS: Capillaroscopy demonstrated a grossly disorganized tumour microcirculation in BCC. Compared with control skin, microvessel width was increased 2.4-fold, area fraction was increased 4.9-fold and length density was increased 5.9-fold. In AK, microvessel width was increased 1.7-fold, area fraction 2.5-fold and length density 3.4-fold. Vessel width and area fraction were significantly greater in BCC than AK. Biopsies showed significant increases in microvessel length density for both BCC and AK compared with control skin, with BCC significantly greater than AK. CONCLUSIONS: Angiogenesis was demonstrated in BCC in humans in vivo, and to a lesser extent in AK.
Aged↗