Melanization in basal cell carcinomas: microscopic characterization of clinically pigmented and non-pigmented tumours.

Clinical and microscopic pigmentation may affect the treatment outcomes in basal cell carcinoma. However, there have not been any in-depth histopathological comparisons between clinically pigmented and non-pigmented basal cell carcinomas with regards to microscopic melanization. The aims of our study were to determine the proportion of pigmented basal cell carcinomas presenting to the National Skin Centre in Singapore, to characterize the histological pattern of melanization and to perform a semi-quantitative analysis of the degree of microscopic melanization of the tumours. Patients with clinical features and histologically confirmed basal cell carcinomas were recruited. Demographic data and clinical characteristics were recorded and basal cell carcinoma sections were examined for histological subtype and pattern of melanization. Twenty-five Chinese patients with 30 basal cell carcinomas were recruited. Three of the five clinically non-pigmented and all of the clinically pigmented basal cell carcinomas had microscopic evidence of melanization. Microscopic melanization in clinically non-pigmented basal cell carcinomas was present only focally or in the centre of the tumour mass. Both groups of basal cell carcinomas may be colonized by melanocytes. Two morphological types of melanocytes, a dendritic and round cell type, were identified. Future research is required to evaluate if the degree of microscopic melanization influences the treatment outcome of basal cell carcinomas.

Clinical and molecular dilemmas in the diagnosis of familial epidermolysis bullosa pruriginosa.

Dystrophic epidermolysis bullosa is a rare and clinically heterogeneous mechanobullous disorder. One unusual clinical variant is epidermolysis bullosa pruriginosa (EBP), in which the combination of pruritus and skin fragility can lead to hypertrophic, lichenified nodules and plaques. This form of inherited epidermolysis bullosa may not develop clinically until adult life, leading to diagnostic confusion with acquired disorders, such as nodular prurigo, lichen simplex, lichen planus, hypertrophic scarring, or dermatitis artefacta. As in all other forms of dystrophic epidermolysis bullosa, the molecular pathology involves mutations in the gene encoding the anchoring fibril protein, type VII collagen (COL7A1), but there is no clear genotype-phenotype correlation in EBP. In this report, we describe a Chinese-Singaporean family with EBP in whom an autosomal dominant glycine substitution mutation, p.G2251E, was identified in exon 86 of the COL7A1 gene. This heterozygous mutation was identified in the genomic DNA of all 4 affected adults tested, as well as 2 clinically unaffected offspring (aged 9-29 years). Based on DNA sequencing, we predict that these individuals may develop EBP later in life, although additional factors leading to disease expression may determine phenotypic expression. Nevertheless, we plan to closely monitor these potentially presymptomatic individuals for symptoms of pruritus and early signs of the genetic disorder.

Risk factors associated with having psoriatic arthritis in patients with cutaneous psoriasis.

The aim of this study was to determine if the following characteristics were associated with the presence of psoriatic arthritis in a sample of psoriasis patients: race, family history of psoriasis and psoriatic arthritis, age of onset of psoriasis, smoking, alcohol consumption and the maximum body surface area (BSA) affected by psoriasis. This was a case-control study involving 400 psoriasis patients who attended the Psoriasis and Photo-medicine clinic in the National Skin Center of Singapore over a 1-year period. Cases were psoriasis patients with psoriatic arthritis while controls were psoriasis patients without psoriatic arthritis. The diagnosis of psoriatic arthritis was made by rheumatologists and participants completed a self-administered standardized questionnaire. The maximum BSA involved was determined from the case notes. Psoriatic arthritis was not significantly associated with sex, race, age of onset of psoriasis, a family history of psoriasis, smoking and alcohol consumption but was significantly associated with a family history of psoriatic arthritis (P < 0.001) and the maximum body surface involved (P = 0.05). Using multivariate analysis to control for variables, the presence of psoriatic arthritis was significantly associated with a family history of psoriatic arthritis (odds ratio [OR] = 20.5; 95% confidence interval [CI] = 2.49-169.10) and the maximum BSA involved (OR = 2.52; 95% CI = 1.33-4.75). Indian psoriatic patients were more likely to have psoriatic arthritis compared to the other races. A family history of psoriatic arthritis and a greater maximum body surface involved may be associated with having psoriatic arthritis in this study population of psoriasis patients.

Treatment of acquired bilateral nevus of ota-like macules (Hori's nevus) with a combination of the 532 nm Q-Switched Nd:YAG laser followed by the 1,064 nm Q-switched Nd:YAG is more effective: prospective study.

BACKGROUND: Acquired bilateral nevus of Ota-like macules (Hori's nevus) is a common dyschromatosis among Asian women. Q-switched lasers have been used successfully as a treatment modality. OBJECTIVE: The purpose of this study was to compare the efficacy of using the Q-switched 532 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser followed by the 1,064 nm laser versus the Q-switched 1,064 nm Nd:YAG laser alone in the treatment of Hori's nevus. METHODS: This is a prospective left-right comparative study. Ten women with bilateral Hori's nevus were recruited and treated with a combination of the Q-switched 532 and 1,064 nm Nd:YAG lasers on the right cheek and the Q-switched 1,064 nm Nd:YAG laser alone on the left cheek. Only one laser treatment session was performed. The degree of pigmentation was objectively recorded with a mexameter. Subjective assessment was made by both patients and two blinded, nontreating dermatologists. RESULTS: At 6 months, there was a statistically significant difference (p = .009) of 35.10 points using objective mexameter measurements between the two sides, favoring the side treated with a combination of 532 and 1,064 nm laser treatment. Subjective grading by the patients and blinded dermatologists also confirmed that combination therapy was more successful after one treatment. Although combination treatment had a higher incidence of mild postinflammatory changes, this disappeared within 2 months. CONCLUSIONS: Concurrent use of the Q-switched 532 nm Nd:YAG laser in combination with the 1,064 nm laser is more effective in pigment clearance than the Q-switched 1,064 nm Nd:YAG laser alone for Hori's nevi.

Photo recall phenomenon: an adverse reaction to taxanes.

Taxanes are a new group of chemotherapeutic agents, which share some pharmacological characteristics with methotrexate. Methotrexate has previously been reported to cause a photo recall phenomenon which develops 3-5 days after UV radiation, suggesting that taxanes can induce a similar reaction. This should be added to the list of cutaneous side-effects of this class of chemotherapeutic agents. We report a case of photo recall phenomenon in a 55-year-old Chinese woman with metastatic breast cancer who was undergoing chemotherapy with taxanes.