The striking correlation of notalgia paresthetica localization with degenerative changes in the spine suggests that spinal nerve impingement may contribute to the pathogenesis of this entity.

Background: Matrix metalloproteinases [MMPs], which degrade the extracellular matrix, play an important role in the invasion and metastasis of squamous cell carcinomas. One MMP, MMP-13, is thought to play a central role in MMP activation. The purpose of this study was to investigate MMP-13 and TIMP-1 expression in squamous cell carcinomas of the head and neck and to relate these levels of expression to histologic patterns of invasion.

Background: Psoriasis vulgaris is a common chronic inflammatory dermatosis. Disorders in keratinocyte proliferation, differentiation, inflammation and immune dysregulation are the major factors implicated in the pathogenesis of psoriasis vulgaris. Methods: The study was performed in skin specimens of 25 patients with psoriasis vulgaris and a control group of 10 individuals without a skin disease. Biopsy specimens from lesional and normal skin were analyzed by immunohistochemical method for expressions of Ki-67, Bcl-2, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL), tumor necrosis factor alpha (TNF-a) and nuclear factor kappa B (NF-kB). In addition, densities of mast cell infiltration were also investigated. Results: Ki-67 and TUNEL indexes and TNF-a and NF-kB expressions were significantly higher in psoriatic epidermis than in normal epidermis (p , 0.05). There was no significant difference at Bcl-2 reactivity between the normal and the psoriatic epidermis (p . 0.05); however, Bcl-2 staining intensity of lymphocytes was higher in psoriatic lesions than in normal dermis (p , 0.05). Additionally, the number of mast cells was significantly higher in psoriatic dermis than in normal skin (p , 0.05). Conclusions: There were several complex factors involved in the pathogenesis of psoriasis. We conclude that cellular damage and apoptosis temporarily coincide with epidermal proliferation during the course of psoriatic hyperplasia. Doger FK, Dikicioglu E, Ergin F, Unal E, Sendur N, Uslu M. Nature of cell kinetics in psoriatic epidermis.

The new proposed classification system for non-invasive urothelial neoplasms does not increase the reproducibility. There is still a need for uniformity in grading in order to compare the different studies and therapies and to provide more accurate information for management.

Background: Notalgia paresthetica (NP) is a sensory neuropathy the pathogenesis of which is not yet completely elucidated. Objective: The aim of this study was to investigate the histopathological changes in NP with special emphasis on cutaneous innervation. Methods: Along with site-matched biopsies from 5 healthy individuals, lesional skin biopsies from 14 cases of NP and biopsies from contralateral nonlesional skin in 9 of these cases were stained with hematoxylin-eosin and Congo red. For immunohistochemical analysis, all samples were stained with two general neural markers (S-100 protein and protein gene product 9.5) and two neuropeptides (vasoactive intestinal polypeptide and substance P). Results: Light microscopy was compatible with postinflammatory hyperpigmentation. Immunohistochemistry did not reveal a significant difference in the staining pattern of lesional skin and control tissue (p > 0.05). Although not reaching statistical significance, the percentage of cases which showed no staining was higher in the group of patients with more chronic NP. Conclusion: The finding of less immunohistochemical staining in cases with more chronicity could be of clinical importance and is worth investigating further.