A Rare Case of Peripheral Primitive Neuroectodermal Tumor Arising from the Minor Salivary Gland in a Young Woman

We report here a case of peripheral primitive neuroectodermal tumor (PNET) arising from the minor salivary gland. A 22-year-old woman was admitted to our hospital for surgical excision of a small painless cheek tumor with a 7-month history. Macroscopically, the tumor measured 10 × 5 × 6mm and was located in the minor salivary gland. Microscopically, the tumor comprised proliferating, small, round cells with scant cytoplasm and high nuclear cytoplasmic ratios. The tumor cells showed some mitotic figures and Homer-Wright-type rosettes. Immunohistochemically, the tumor cells were immunopositive for CD99, synaptophysin, CD56, S-100 protein, and vimentin. Based on these findings, the patient was diagnosed as having PNET arising from the minor salivary gland. There are very few case reports of PNET in the head and neck region, and to the best of our knowledge, this is the first case report of PNET arising from the minor salivary gland

p53 phosphorylation in mouse skin and in vitro human skin model by high-dose-radiation exposure

The skin is an eternal organ that is most frequently exposed to radiation. High-dose radiation initiates and promotes acute radiation injury. Thus, it is important to investigate the influence of high-dose radiation exposure on the skin at the molecular level. The post-translational modification of p53 plays a central role in radiation responses, including apoptosis and cell growth arrest. Although it is well known that ataxia telangiectasia mutated (ATM) kinase and DNA-dependent protein kinase (DNA-PK) can phosphorylate Ser15/Ser18 of p53 in vitro, the post-translational modification pattern and the modifier of p53 in the skin after exposure to high-dose X-rays are not yet well understood. Here we show that the phosphorylation of p53 on Ser15/Ser18, as well as the phosphorylation of histone H2AX on Ser139, was detected in the keratinocytes of the mouse skin and human skin models after high-dose X-ray irradiation. Following high-dose X-ray irradiation, both proteins were also phosphorylated in the skin keratinocytes of both ATM gene knockout mice and DNA-PK-deficient SCID mice

Differentiation-Associated Localization of nPKCμ, a Ca++-Independent Protein Kinase C, in Normal Human Skin and Skin Diseases

The expression of nPKCμ, a Ca++-independent isoform of protein kinase C in normal human skin, and skin from patients with psoriasis, squamous cell carcinoma, basal cell epithelioma, nevus pigmentosus, and seborrheic keratosis, were examined by immunohistochemical staining using a polyclonal antibody raised against a synthetic peptide at a diverse region of the nPKCμ molecule. In normal epidermis, the strongest staining was observed in the uppermost granular layer with no staining of the spinous or basal layers. The inner layer of the intra-epidermal eccrine duct was also strongly stained. Weak staining was observed in several layers of the outer root sheath of the follicular infundibulum. No staining was detected in the inner root sheath of the hair follicles, hair matrix, sebaceous gland, eccrine gland, intradermal eccrine duct, arrectores pilorum, melanocytes, Langerhans cells, fibroblasts, or blood vessels. In psoriatic skin, stained keratinocytes were distributed in the suprabasal layers with the most being observed in the uppermost layer and the least in layers closed to the basal layer. In squamous cell carcinoma, weak staining was observed in the keratotic cells around horny pearls. In the basal cell epithelioma and nevus pigmentosus, the cells were not stained, whereas in seborrheic keratosis, cells that stained were located in the granular layer. We conclude from the evidence presented above that nPKCμ is expressed in close association with epidermal differentiation in normal skin and skin diseases