Effect of dipolar aprotic permeability enhancers on the basal stratum corneum.

The effect of dimethyl sulfoxide, dimethyl formamide, and dimethyl acetamide on the basal stratum corneum of excised nude mouse skin was investigated. All of these dipolar aprotic solvents caused a swelling of the basal stratum corneum cells and a disruption of the normal keratin pattern. This behavior suggests that dipolar aprotic solvents might alter the barrier properties of the basal stratum corneum cells. To test this hypothesis, the distribution of topically applied, electron-dense divalent metal ions (Hg2+ and Ni2+) was studied in excised nude mouse skin which had been perturbed by the application of dipolar aprotic solvents, and in controls which had not been so treated. In control skin membranes, Hg2+ and Ni2+ were located almost exclusively in the intercellular space of the stratum corneum. However, with the application of a dipolar aprotic solvent, Hg2+ and Ni2+ were found in the intercellular spaces and inside the basal stratum corneum cells, where they appeared to be primarily associated with the cytoplasmic filaments. Sulfide precipitation allowed for the localization of Hg2+ and Ni2+, and subsequent chemical identification by energy-dispersive X-ray microanalysis. The spatial resolution of X-ray microanalysis studies was approximately 0.5-0.75 micron. The spatial alteration in mercury and nickel precipitate distribution, which occurs when the skin is pretreated with a dipolar aprotic solvent, is consistent with the hypothesis that the pathway of Hg2+ and Ni2+ diffusion through the basal stratum corneum has also been modified.

Metastatic basal cell carcinoma to the lung.

Basal cell carcinoma is a relatively common tumor with an increasing incidence. Despite this, metastatic disease is an extremely rare event. A review of metastatic basal cell carcinoma is presented.

Pedunculated proliferative papillomatosis.

Skin tags (soft fibromas) are benign connective tissue neoplasms of the dermis. As a rule they occur as soft, skin-colored, filiform, often pedunculated growths in intertriginous areas. The classification and naming of these lesions is somewhat arbitrary due to their banal clinical and histological spectrum of characteristics. We report an unusual case of a peculiar proliferation of dermal and epidermal components that clinically and histologically appears to fit into this category of soft fibroma.

Multiple warty dyskeratomas of the scalp.

Two patients presented with the unusual condition of multiple warty dyskeratomas on the scalp. Biopsies of affected skin stained positive with human keratin monoclonal antibodies HKN-6 and -7, specific for cortex and inner root sheath of normal human hair, respectively. Multiple warty dyskeratomas are a rare occurrence and their aetiopathogenesis remains elusive. Positive immunohistochemical staining of a lesion with antikeratin antibodies HKN-6 and -7, specific for human hair keratin, suggests a follicular origin for warty dyskeratoma.

Cutaneous and neurologic disease associated with HTLV-I infection.

Human T-lymphotropic virus type I (HTLV-I) is the etiologic agent of HTLV-I associated myelopathy (HAM)/tropical spastic paresis (TSP), and adult T-cell leukemia/lymphoma (ATLL). ATLL has been associated with HTLV-I in the southeastern United States. However, to our knowledge, no case reports of HAM/TSP in association with ATLL occurring in the United States have been described. We describe a 40-year-old black woman with a 10-year history of recalcitrant psoriasiform eruption and erythrodermic flares. Medical history is additionally significant for a 2-year history of HTLV-I-associated myelopathy and lower extremity spastic paresis. Polymerase chain reaction with Southern blot analysis was used to detect HTLV-I proviral genome from frozen skin biopsy specimens and peripheral blood mononuclear cells.