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Recessive dystrophic epidermolysis bullosa (RDEB) is a severe hereditary mechanobullous disease resulting from mutations in the COL7A1 gene, coding for type VII collagen. Patients with RDEB tend to develop squamous cell carcinomas (SCCs) at sites of chronic ulceration or scarring on the whole body. Distinguishing SCC from benign hyperkeratotic lesions is often difficult, not only clinically but also histologically in patients with RDEB. We investigated several matrix metallopeptidase (MMP) subtypes by comparing the DNA amplification microarray findings between evident SCCs and benign hyperkeratotic lesions in the same patient with RDEB. We report that MMP13 was found to be strongly positive in SCCs but negative in benign hyperkeratotic lesions. We found that there is an evident difference in the transitional area between SCCs and benign hyperkeratotic lesions. We propose that MMP13 may be a useful differentiating marker between SCC and benign hyperkeratotic lesions in RDEB., (© 2014 British Association of Dermatologists.)

Minimally invasive diagnostic tools have received increased attention for diagnosis, screening and management of nonmelanoma skin cancer (NMSC). Several modalities are commercially available, including high frequency ultrasound, optical coherence tomography and confocal microscopy. While systematic clinical analyses are often lacking, recent reports have shown promising results for reflectance confocal microscopy (RCM) for diagnosis of actinic keratoses and basal cell carcinoma.

Background: Lichenoid keratosis (LK) is a well-described entity which has been proposed to represent an immunological or regressive response to pre-existing epidermal lesions such as solar lentigines or seborrhoeic keratoses., Objectives: To evaluate the dermoscopic criteria of a series of cases of LK with remaining areas of seborrhoeic keratosis which were both dermoscopically and histologically diagnosed., Methods: Pigmented lesions with dermoscopic areas of seborrhoeic keratosis and LK in the same tumour were consecutively diagnosed and prospectively included in the study. All pigmented lesions were examined and registered using DermLite Foto equipment (3Gen, LLC, Dana Point, CA, U.S.A.), at 10-fold magnification, at the Dermatology Department of Hospital de Sant Pau i Santa Tecla (Tarragona, Spain), between 1 January 2003 and 31 December 2005., Results: In total, 24 cases of lesions with dermoscopic areas of seborrhoeic keratosis and LK were collected. In four lesions (17%), the clinical differential diagnosis without dermoscopy included malignant melanoma and in seven lesions (29%), basal cell carcinoma. The diagnosis of LK was clinically considered without dermoscopy in only six cases (25%). A granular pattern was observed to be distributed throughout the LK areas of the lesions. This pattern consisted of the presence of brownish-grey, bluish-grey or whitish-grey coarse granules that formed, in 11 cases (46%), globules and/or short lines. In one lesion, located on the face, these short lines produced annular or rhomboid structures as seen in lentigo maligna melanoma., Conclusions: Dermoscopy is a useful tool which assists in the correct clinical recognition of LK, which may also potentially illuminate the pathogenesis of these tumours, showing the intermediate stage of regressing epidermal lesions in an LK.

These guidelines stemmed from a consensus meeting held by the British Photobiology Group (BPG) in 1999. Following this meeting one of the authors (J.M.M.) was invited to draw up guidelines for the management of actinic keratoses by the British Association of Dermatologists Therapy Guidelines and Audit Subcommittee. Relevant evidence was sought using the search terms 'solar keratosis' and 'actinic keratosis' in Medline from 1966 onwards. Additional and earlier literature was reviewed on the basis of references within post-1966 publications. All articles of apparent relevance were reviewed independently of the nature of the publication. The quality of the evidence elicited has been indicated. The National Ambulatory Medical Care Survey (U.S.A.) was used for further data on topical chemotherapy. Papers were reviewed and discussed by the contributors to the BPG Workshop (see Acknowledgments). Recommendations are evidence based where possible. Strength of recommendation is coupled with quality of evidence. Strength of recommendation includes consideration of apparent cost-benefit and practical considerations. Quality of evidence reflects the nature of the trial structure that provides data of efficacy.

Background: The accuracy of clinical diagnosis of nonpigmented, facial actinic keratosis (AK) is often suboptimal, even for experienced clinicians., Objectives: To investigate the dermoscopic features of nonpigmented AK located on the head/neck that may assist the clinical diagnosis., Methods: Forty-one nonpigmented AKs on facial sites were examined by dermoscopy for any consistent underlying features. Lesions were gathered from skin cancer centres in Australia, Austria, Italy and the U.S.A. All cases were diagnosed histopathologically., Results: Four essential dermoscopic features were observed in facial AK: (i) erythema, revealing a marked pink-to-red 'pseudonetwork' surrounding the hair follicles (95%); (ii) white-to-yellow surface scale (85%); (iii) fine, linear-wavy vessels surrounding the hair follicles (81%); and (vi) hair follicle openings filled with yellowish keratotic plugs (66%) and/or surrounded by a white halo (100%). These features combined, in 95% of cases, to produce a peculiar 'strawberry' appearance., Conclusions: A dermoscopic model of 'strawberry' pattern is presented, which may prove helpful in the in vivo diagnosis of nonpigmented, facial AK. A limitation of this study is the lack of testing of the specificity of the described dermoscopic criteria in differentiating nonpigmented AKs from other nonpigmented skin lesions at this site.

Confetti leucoderma can occur in a variety of unrelated skin disorders and is often a diagnostic challenge. We describe a 33-year-old man with a history of mycosis fungoides and vitiligo. He developed disseminated 1-2-mm round-shaped leucodermic lesions 6 months after psoralen photochemotherapy and 12 months after systemic therapy with interferon. The skin lesions had a discrete hyperkeratotic scale. Multiple skin biopsies and immunohistochemical studies showed lamellar orthohyperkeratosis, papillomatosis, hypomelanotic keratinocytes but a normal number of melanocytes. Langerhans cells, in contrast, were reduced in lesional skin. Electron microscopy disclosed only a few type I and II melanosomes in lesional melanocytes, while keratinocytes were largely devoid of any melanosomes. This constellation of clinical, immunohistochemical and ultrastructural findings has not been reported before and distinguishes our case from leucoderma punctatum, idiopathic guttate hypomelanosis and disseminated hypopigmented keratoses. We suggest that the skin lesions observed in our patient represent an unusual response to ultraviolet damage to melanocytes followed by reactive epidermal hyperkeratosis.

Background: Progression of cutaneous squamous neoplasms from actinic keratosis (AK) to Bowen's disease (BD; squamous cell carcinoma in situ) has important implications for clinical management and treatment, thus requiring accurate diagnosis. p16INK4a is a cell cycle regulatory tumour suppressor protein that negatively regulates D-type cyclins in the G1 cell cycle phase via intimate interplay with the retinoblastoma gene. Expression of a paraffin-reactive p16INK4a marker has recently been shown to increase in cervical squamous neoplasms as lesions progress from low-grade dysplasia to squamous cell carcinoma in situ. p16INK4a expression in the progression of squamous cutaneous neoplasia, however, has not been evaluated., Objectives: To evaluate p16INK4a expression in the progression of squamous cutaneous neoplasia., Methods: Biopsies of 203 squamous cutaneous neoplasms with unequivocal features of AK (n = 87) and BD (n = 116) as well as a benign squamous control group (verruca vulgaris: n = 10; seborrhoeic keratosis: n = 11; scar tissue: n = 8) obtained between January and December 2001 at Henry Ford Hospital (Detroit, MI, U.S.A.) were immunostained for p16INK4a (Dako; clone E6H4; dilution 1 : 50) using large core (1.5 mm) tissue microarray analysis. Nuclear/cytoplasmic immunoreactivity in > 10% of neoplastic cells was considered positive., Results: Of 203 cases, 166 (81.8%) were interpretable (AK 59; BD 107). Mean patient age was 71.0 years (range 33-93); 57% were male. Sites of involvement were: head and extremities 75.9%, trunk/buttocks 21.7%, genital region 2.4%. p16INK4a immunostaining was positive in 90 of 107 (84.1%) BD cases, four of 59 (6.8%) AK cases and none of 29 benign squamous controls. The sensitivity and specificity of p16INK4a for a diagnosis of BD (vs. benign squamous controls/AK) was 84.1% and 95.5%, respectively (P < 0.0001, Fisher's exact test, two-sided)., Conclusions: p16INK4a is a sensitive and specific marker for distinguishing BD from AK/benign squamous cutaneous lesions and may be helpful as an adjunct to histomorphology in the diagnosis and appropriate clinical management of these lesions.

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.

Solar keratoses (SKs) or actinic keratoses are common dysplastic epidermal lesions which occur in pale-skinned individuals who are chronically exposed to intense sunlight. Together with basal cell carcinomas and squamous cell carcinomas, they constitute a major public health problem in such individuals. Reported SK prevalence rates range from 11 to 25% in various northern hemisphere populations, and amongst Australian adults the range is from 40 to 60%. In the only study to date reporting SK incidence data, 60% of subjects aged 40 years and over with SKs at baseline developed new lesions during 12 months of follow-up, compared with only 19% of those who were lesion-free on the first examination. Because existing epidemiological data on SKs are sparse, very little is known of their natural history, their role in carcinogenesis, or their preventability. In this review, current knowledge about the aetiology, diagnosis, and occurrence of SKs is discussed, as is the need for prospective studies in unselected communities. With accurate baseline data, public health authorities should be in a better position to determine the best preventive strategies, and to evaluate the effectiveness of these programmes.

With rare exceptions, the presence of cornoid lamellae in skin biopsy specimens is considered diagnostic of porokeratosis. Since the initial descriptions of this condition by Mibelli (1893) and Respighi (1893), there has been debate concerning its relationship to the eccrine sweat duct. This paper describes an epidermal naevus, which pathologically demonstrated gross examples of cornoid lamellae associated exclusively with the eccrine duct and ostia, and which appears to represent a naevus or benign hamartoma of these structures. This entity needs to be clearly differentiated from porokeratosis of Mibelli.

The final alpha-keratin compositions attained in the outer horny layer of 16 dyskeratoses have been compared with the series of compositions which is produced during normal epidermal differentiation. In each case, the abnormal outer horny layer composition corresponded with that of normal basal, spinous, granular or inner horny cells, with, in some cases, the addition of alpha-keratins characteristic of hyperproliferating/regenerating keratinocytes. The results have implications for the aetiology of these diseases. In addition, the distinction between the alpha-keratin patterns in certain of the conditions was sufficiently clear to allow the use of the technique as a non-invasive aid to diagnosis.