J. Arrese Estrada

Factor-XIIIa-Positive Dendrocytes and the Dermal Microvascular Unit

We present an immunohistochemical study with factor XIIIa antibody performed in a variety of cutaneous diseases. Our observations suggest that factor-XIIIa-positive dendrocytes, in noninflammatory conWe present an immunohistochemical study with factor XIIIa antibody performed in a variety of cutaneous diseases. Our observations suggest that factor-XIIIa-positive dendrocytes, in noninflammatory conditions, may be resident phagocytic cells intimately associated with the microvascular units of the skin.

Oral Cyclosporin and Alopecia areata

A 30-year-old woman with severe alopecia areata of the scalp was treated with oral cyclosporin for 3 months. Clinical, histological and immunohistochemical assessments failed to reveal any improvement.

Cutaneous manifestations in systemic trichosporonosis

Trichosporonosis due to Trichosporon beigelii is increasingly recognized in neutropenic immunocompromised patients. We report the clinical and histological presentation of three cases, as well as a study of the prevalence of T. beigelii colonization of normal‐looking skin in patients receiving intensive chemotherapy for cancer.

Immunohistochemical Expression of Epidermal Growth Factor Receptors in Nuclei of a Subpopulation of Keratinocytes and Sweat Gland Cells

We have raised a polyclonal antibody to the 170-kD epidermal growth factor receptor. We found an intercellular pattern of immunoreactivity in the epidermis as well as a positivity of the cytoplasm of keratinocytes and eccrine secretory cells. In some samples, a nuclear labelling was evidenced in these type of cells. There is a close resemblance in the topographical distribution of these cells with nuclear labelling and those synthesizing DNA under phytohaemagglutinin stimulation.

Cyanoacrylate skin surface stripping: an improved approach for distinguishing dysplastic nevi from malignant melanomas

We present a novel approach for improving the management of patients with pigmented neoplasms including malignant melanomas and dysplastic nevi. A cohort of 215 dysplastic nevi and malignant melanomas was studied by cyanoacrylate skin surface stripping (CSSS) and conventional histology. Presence of atypical melanocytes was found in the stratum corneum in more than 95% of malignant melanomas and was always absent in dysplastic nevi. We conclude that this non‐invasive technique is rapid, easy to perform, and inexpensive. Its specificity and sensitivity are high enough to be considered by clinicians as an aid for distinguishing dysplastic nevi from malignant melanomas. We recommend this ancillary technique as a screening procedure though not as a substitute for conservative excisional biopsy, when doubt persists in the diagnosis of atypical pigmented neoplasms.

Dermal dendrocytes and photochemotherapy

We studied the fate of dermal dendrocytes in patients treated with psoralens and ultraviolet light by combining immunohistochemistry and computerized image analysis. Factor-XIIIa-positive dermal dendrocytes were found to be altered in these patients. When compared with controls, dermal dendrocytes were often increased in number and had an uneven size and tissue distribution. Their cytoplasm was occasionally fragmented. These changes were more pronounced when early photosclerosis was present. The alterations described probably reflect vascular changes, and may be responsible for immunomodulating actions and disorder of the connective tissue structure induced by ultraviolet light.