Linear porokeratosis associated with multiple squamous cell carcinomas.

Linear porokeratosis is a rare subtype of porokeratosis with a higher rate of malignant transformation than other subtypes of porokeratosis. Identification of cornoid lamellae on histology allows for definitive diagnosis, which makes high clinical suspicion and appropriate biopsy essential in establishing the correct diagnosis and developing an effective management plan. We present a case report of linear porokeratosis and discuss aspects of etiology, diagnosis, and management.

Mild to Moderate Dysphagia Following Very Low-dose Abobotulinumtoxin A for Platysmal Bands.

Onabotulinumtoxin A (Botox) can be a safe and successful off-label treatment of vertical platysma bands of various severities. Due to risk of the botulinum toxin diffusing to the underlying anatomic structures such as the deglutition muscles, the larynx, and the neck flexors, a maximal dose of 100 units has been suggested and there have been no known reports of untoward effects with doses less than 60 units. We present a case of mild to moderate dysphagia in a patient after very low doses of Abobutulinumtoxin (60 units, equivalent to 20 units of Onabotulinumtoxin using a 3:1 conversion ratio).

Computer-aided classification of melanocytic lesions using dermoscopic images.

Background: Computer-assisted diagnosis of dermoscopic images of skin lesions has the potential to improve melanoma early detection.

Objective: We sought to evaluate the performance of a novel classifier that uses decision forest classification of dermoscopic images to generate a lesion severity score.

Methods: Severity scores were calculated for 173 dermoscopic images of skin lesions with known histologic diagnosis (39 melanomas, 14 nonmelanoma skin cancers, and 120 benign lesions).

Langerhans Cells Facilitate UVB-Induced Epidermal Carcinogenesis.

UVB light is considered the major environmental inducer of human keratinocyte (KC) DNA mutations, including within the tumor-suppressor gene p53, and chronic exposure is associated with cutaneous squamous cell carcinoma formation. Langerhans cells (LCs) comprise a dendritic network within the suprabasilar epidermis, yet the role of LCs in UVB-induced carcinogenesis is largely unknown. Herein we show that LC-intact epidermis develops UVB-induced tumors more readily than LC-deficient epidermis.

Mechanisms of chemical cooperative carcinogenesis by epidermal Langerhans cells.

Cutaneous squamous cell carcinoma (SCC) is the most prevalent invasive malignancy with metastatic potential. The epidermis is exposed to a variety of environmental DNA-damaging chemicals, principal among which are polyaromatic hydrocarbons (PAHs) ubiquitous in the environment, tobacco smoke, and broiled meats. Langerhans cells (LCs) comprise a network of dendritic cells situated adjacent to basal, suprabasal, and follicular infundibular keratinocytes that when mutated can give rise to SCC, and LC-intact mice are markedly more susceptible than LC-deficient mice to chemical carcinogenesis provoked by initiation with the model PAH, 7,12-dimethylbenz[a]anthracene (DMBA).

EBI3 deficiency leads to diminished T helper type 1 and increased T helper type 2 mediated airway inflammation.

Despite extensive investigation of the signals required for development of T helper type 1 (Th1) and type 2 (Th2) immune responses, the mechanisms involved are still not well-defined. A critical role for Epstein-Barr virus-induced gene 3 (EBI3) in these responses has been proposed. EBI3, initially discovered as a transcriptionally activated gene in Epstein-Barr virus-infected B lymphocytes, codes for a subunit of the cytokine interleukin-27 (IL-27).

The contribution of Langerhans cells to cutaneous malignancy.

The skin is at the forefront of environmental exposures, such as ultraviolet radiation and a myriad of chemicals, and is at risk for malignant transformation. The skin is a highly responsive immunological organ that contains a unique population of immature intraepidermal dendritic cells (DCs) called Langerhans cells (LCs). Although LCs show morphological and migratory changes in response to epidermal perturbation, and can function as antigen-presenting cells to activate T cells, their role in carcinogenesis is unknown.