Sebum, cosmetics, and skin care.

Recent contributions to the understanding of the physiology and biochemistry of sebum production and of the lipids on the skin surface are leading to the development of effective strategies to regulate excessive sebum production and its consequences through the use of cosmetics and skin care products.

Confocal reflectance imaging of folliculitis in vivo: correlation with routine histology.

Near-infrared confocal reflectance microscopy (CM) is a high-resolution: non-invasive imaging technique with promising future in dermatology. A pustular lesion from a 35-year-old male with a known history of folliculitis was non-invasively viewed with CM and later biopsied. Optical sections were correlated with routine histology. This optical technique allows us to view non-invasively transverse skin sections to a controlled depth in real time. In the CM images, tissue can be visualize with cellular and subcellular detail as shown by imaging infiltrating neutrophils (PMNs) within the subcorneal pustule of a superficial folliculitis in vivo.

Syringofibrocarcinoma versus squamous cell carcinoma involving syringofibroadenoma: is there a malignant counterpart of Mascaro's syringofibroadenoma?

Although a benign syringofibroadenoma has been recognized as an eccrine tumor exhibiting net-like ductal proliferation embedded in fibroma-like stroma, a malignant counterpart has not been described heretofore. An 82-year-old man with severely sun-damaged skin had a 3 cm plaque in the dorsum of his left hand. The clinical diagnosis was squamous cell carcinoma. Histologically, the lesion was a bowenoid squamous cell carcinoma, both in situ (Bowen's disease-like) and bluntly invasive, with a concurrent phase showing unequivocal and widespread ductal differentiation, local expression of carcinoembryonic antigen, and sclerotic stroma. This syringofibrocarcinoma also impinged laterally on a mature and benign syringofibroadenoma and occurred above a minute deep dermal trichoepithelioma. This report presents a probably unrecognized new malignant tumor, clearly distinct yet related to both squamous cell carcinoma and eccrine carcinoma. Because its organoid architecture and the resemblance to and impingement on syringofibroadenoma, the term syringofibrocarcinoma is proposed.

A beta 2RARE-LacZ transgene identifies retinoic acid-mediated transcriptional activation in distinct cutaneous sites.

Retinoic acid and its derivatives (retinoids) exert profound influences on epithelial growth differentiation in a variety of tissues, including the skin. How retinoic acid mediates these effects is not fully understood. The recent cloning of a series of nuclear receptors for retinoic acid (RARs) has demonstrated that these proteins can function as ligand-inducible transcriptional enhancing factors. Moreover, all receptors are members of the steroid/thyroid hormone multigene family. In vitro studies have demonstrated the expression of RAR alpha, RAR beta, and RAR gamma in various cell types found in the skin. While multiple isoforms exist for each of the three RARs, it is unclear where each of these receptors functions in vivo to mediate the tissue-specific effects of retinoic acid. As a first step in determining sites of retinoic acid-mediated transcriptional activation in the skin and its appendages, we developed a transgenic model in which the retinoic acid response element (RARE) of the RAR beta 2 isoform is linked to a beta-galactosidase reporter gene. Our observations consistently demonstrate that retinoic acid transcriptionally activates the beta 2RARE in distinct areas of the skin. Of interest, certain of these areas are known to contain stem cells. These data clearly demonstrate that this type of transgenic "reporter" model can be used to further define retinoic acid-regulated signal transduction pathways in the skin, as well as other complex tissues. Furthermore, these observations raise the possibility that transcriptional activation of RAR beta 2 may regulate the growth and differentiation programs of selected populations of stem cells in the skin and its appendages.

Multiple agminated pigmented Spitz nevi (mimicking acral lentiginous malignant melanoma and dysplastic nevus) in an African-American girl.

BACKGROUND: Reed's nevi are distinguished from Sptiz tumors by their significant melanogenesis and growth pattern. They may be confused with melanoma on clinical and histologic grounds. CASE REPORT: An unusual case in which multiple agminated Reed's nevi mimicked acral lentiginous malignant melanoma in an African-American girl is presented. A critical review of the literature is presented to assist in the diagnosis. CONCLUSIONS: Awareness of this entity and of its possible clinical presentations and judicious application of conventional hematoxylin-eosin microscopic criteria remain the most useful methods to bring the correct diagnosis in most instances. Mutilating or excessive surgery may be avoided for most cases of pigmented spindle and epithelioid cell nevus.

Effects of tretinoin on photodamaged skin. A histologic study.

The histologic effects of topical tretinoin therapy on photodamaged facial skin were investigated in two 24-week, double-blind, randomized, vehicle-controlled studies involving 533 subjects at eight US centers. Three concentrations of tretinoin (0.05%, 0.01%, and 0.001%) in a new emollient cream were studied. Pretherapy and posttherapy biopsy specimens from the periorbital (crow's foot) area were examined by conventional light microscopy and computerized image analysis. Four significant dose-dependent differences from vehicle were found in the tretinoin groups: increased epidermal thickness, increased granular layer thickness, decreased melanin content, and stratum corneum compaction. There was no significant difference between 0.001% tretinoin and the vehicle, and no obvious dermal changes were detected in any group. The four epidermal changes in tretinoin-treated skin establish the biologic activity of the new emollient cream formulation and may partially account for the clinical improvements in photodamage observed in the same group of subjects.

Cutaneous metaplastic synovial cyst.

Metaplastic synovial cyst, a recently described entity, is histologically characterized by a cystic cavity lined by metaplastic synovial tissue that is often hyperplastic and protrudes into its lumen as villous structures. Clinically, these lesions resemble suture granuloma and develop at the site of previous surgical trauma. We have studied 4 cases of this unusual entity and have investigated the immunohistochemical profile in an effort to determine the nature and derivation of their lining tissue. One of our cases is unique since the lesion was associated with a basal cell carcinoma. A history of previous surgery was noted in one, and history of trauma in 2 of the 4 cases. Our immunohistochemical observations confirmed a mesenchymal derivation for the "synovial like villous structures" but non-availability of a specific "synovial" marker does not permit us to conclude with certainty the synovial nature of the metaplastic tissue. Cutaneous metaplastic synovial cysts are unique lesions which deserve attention and should be included in the differential diagnosis of cutaneous cysts.

Congenital self-healing reticulohistiocytosis. A new entity in the differential diagnosis of neonatal papulovesicular eruptions.

A case of congenital self-healing reticulohistiocytosis is described. The case is different from those previously described because papulovesicles, rather than the papulonodules that are usually characteristic of this disease, predominated. All lesions regressed within 2 months of presentation, and at 2-year follow-up, the patient continues to develop normally without recurrence of the eruption or progression to internal organ involvement. Electron microscopic examination revealed numerous Langerhans' granules admixed with myelinlike laminated dense granules characteristic of this disease. The unique physical presentation in this case, as well as the criteria used to differentiate this disorder from the more malignant forms of histiocytosis and other childhood papulovesicular eruptions, is emphasized.

Vasa previa: parto vaginal con nina viva (comunicacion del primer caso en Venezuela). / Vasa praevia: vaginal labor with alive newborn infant (communication of the first case in Venezuela)

Se describe un caso de vasa previa asistido por via vaginal con sobrevida fetal. Se hace referencia a otro caso (1) tambien exitoso, atendido por cesarea. Se realiza una somera revision de la literatura reciente sobre este tema

Enanismo tanatoforico. (Communicacion del primer caso en Venzuela). / Tanatophoric dwarfism. (Communication of the first case in Venezuela)

Se comunica el primer caso de enanismo tanatoforico en Venezuela, se hacen comentarios en relacion al mismo y se hace somera revision de la literatura sobre el tema

Results of radiotherapy in control of stage I and II non-Hodgkin's lymphoma.

We retrospectively analyzed 114 patients with non-Hodgkin's lymphoma, clinical stages I and II, classified by the criteria of Rappaport and treated by radiotherapy alone. Of 84 patients classifiable, one-third were nodular and two-thirds diffuse lymphomas. Berkson-Gage actuarial and relapse-free survivals were determined for these two groups and for subgroups stratified by histology, stage, and by presence or absence of extranodal disease. Five year relapse-free and overall survivals were 83% and 100%, respectively, for the nodular group and 37% and 59% for the diffuse group. Extranodal involvement was less frequent in the nodular (19%) than in the diffuse (52%) group, where it was associated with Stage IE disease and increased relapse-free and actuarial survival. Histopathological subtype in the diffuse group (histiocytic versus combined lymphocytic poorly differentiated and mixed lymphocytic-histiocytic) did not influence survival. Extranodal involvement and stage I disease were associated with better survival in the diffuse histiocytic group. Successful radiotherapy for all stages of disease, all histologies, was not correlated with extended versus involved fields, and 89% of the relapses in the entire series were by wide dissemination.

Expression of herpesvirus in adherent cells derived from bone marrow of latently infected guinea pigs.

The role of bone marrow adherent cells in the latency of guinea pig herpes-like virus (GPHLV) was explored. Cultures of macrophage-enriched adherent cells derived from infected guinea pigs were examined for evidence of latent GPHLV infection. Expression of the virus was detected in these cultures 9 to 10 days after in vitro cultivation. Increasing virus infectivity titers as well as light and electron microscopic evidence of virion assembly in macrophages and fibroblasts were demonstrated. Infections virus was detected in the bone marrow adherent cells that had attached for 30 or 120 minutes but only following reverse cocultivation. The data showed not only that the bone marrow adherent cells were susceptible to GPHLV in vitro but also that GPHLV was harbored by the macrophage-enriched bone marrow population in vivo in latently infected guinea pigs.