Head and neck manifestations of langerhan's cell histiocytosis in children: a 46-year experience.

OBJECTIVE: Langerhan's cell histiocytosis (LCH) is an uncommon disease characterized by abnormal proliferation of polyclonal Langerhan's cells, most commonly presenting with head and neck manifestations. This is a report of a series of patients with LCH at St. Jude Children's Research Hospital over a 46-year period. The purpose was to examine the head and neck presentations of LCH, their treatments and outcomes, and to compare with other previously reported series. METHODS: This was a retrospective study of all patients with a diagnosis of LCH who presented to St. Jude Children's Research Hospital, Memphis, TN between 1962 and 2008. Patients who presented with an initial diagnosis of LCH but were later determined to not fit the diagnostic criteria were excluded from the study. IRB approval was obtained and a chart review was conducted to collect data regarding demographics, tumor site(s) and manifestations, pathology, treatment, surgical procedures, and outcomes. This data was compiled and compared to previously published results. RESULTS: Eighty-eight cases of LCH with at least one head and neck manifestation were diagnosed during the period studied. There were 54 males and 34 females, with an average age of onset of 4.1 years. The most common lesions were those involving the skull (44.3%) and cervical lymph nodes (40.9%). The most common treatment was chemotherapy (80%) and corticosteroids (64%), with vinblastine being the most common chemotherapeutic agent. Surgical intervention occurred in 39% of cases. Total mortality due to LCH was 9.1%. The results were found to generally concur with other previously published studies. CONCLUSION: This study represents the largest series of head and neck manifestations of LCH reported to date. Although LCH is a rare disease, it often mimics other common head and neck pathologies and therefore requires a high index of suspicion. Biopsy is required for definitive diagnosis and the mainstay of treatment is chemotherapy.

Characterization of a synthetic bioactive polymer by nonlinear optical microscopy.

Tissue Engineering is a new emerging field that offers many possibilities to produce three-dimensional and functional tissues like ligaments or scaffolds. The biocompatibility of these materials is crucial in tissue engineering, since they should be integrated in situ and should induce a good cell adhesion and proliferation. One of the most promising materials used for tissue engineering are polyesters such as Poly-ε-caprolactone (PCL), which is used in this work. In our case, the bio-integration is reached by grafting a bioactive polymer (pNaSS) on a PCL surface. Using nonlinear microscopy, PCL structure is visualized by SHG and proteins and cells by two-photon excitation autofluorescence generation. A comparative study between grafted and nongrafted polymer films is provided. We demonstrate that the polymer grafting improves the protein adsorption by a factor of 75% and increase the cell spreading onto the polymer surface. Since the spreading is directly related to cell adhesion and proliferation, we demonstrate that the pNaSS grafting promotes PCL biocompatibility.