摘要:

We evaluated the incidence, morphology, and immunophenotype of intraepidermal collections of mononuclear cells (ICMC) in a large number of inflammatory dermatosis and cutaneous lymphomas. ICMC appeared as small to large aggregates of cells, showing a morphology variable from monocytes to obvious dendritic cells, admixed with rare lymphocytes. ICMC were recognized in the epidermis or within hair follicle epithelium, and were either loosely or compactly arranged. ICMC were identified in 124 of 1,248 skin biopsies (9.9%) of inflammatory or lymphoid infiltrates, and were particularly frequent in spongiotic (43.4%) and in lichenoid dermatitis (10%), whereas they were rarely found in nonspecific superficial dermatitis (3.8%) and in psoriasis (4.7%). ICMC were also frequent in cutaneous T-cell lymphoma (13.3%), where they mimicked Pautrier abscesses. The ICMC forming cells showed a unique phenotype: the majority of them expressed CD1a and S-100, and lacked CD14, similar to mature Langerhans cells, but they were also strongly labeled by anti-CD11b, anti-CD36, and anti-CD68. Moreover, a subpopulation of them expressed CD83, an antigen that is usually absent on Langerhans cells. The occurrence of ICMC is a rather frequent, although hitherto poorly studied, phenomenon, occurring in several dermatosis, but particularly frequent in spongiosis-associated skin reactions. The cells within ICMC are represented by dendritic cells and dendritic cell precursors, whose phenotype indicates their derivation from circulating monocytes and differentiation into mature Langerhans cells.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

To characterize the immunophenotype of inflammatory cells in lichen sclerosus (LS), we performed a comparative case control study using one-and two-color immunohistochemistry and the nitro blue tetrazolium (NBT) reaction. Study material consisted of 100 biopsies from patients with LS or from 12 control groups consisting of inflammatory, scarring, and depigmenting cutaneous disorders. In addition, fresh tissue was sampled from four vulvectomy specimens for NBT testing. The typical inflammatory infiltrate of LS contained numerous epidermotropic CD3+, CD8+, CD57+ cells, increased intraepidermal HLA-DR+ cells, and a dermal infiltrate rich in CD8+, CD57+, HLA-DR+, and CD68+ inflammatory cells. Comparing LS to the 12 control groups, epidermotropic CD57+ lymphocytes independently predicted LS (P = 0.006, logistic regression, multivariate analysis). Among the 12 control groups, only specimens of the inflammatory stage of morphea exhibited numerous dermal CD57+ lymphocytes. Two-color immunohistochemistry confirmed the CD3+/CD8+CD57+ and CD3+/CD8+/CD57+HLA-DR+ epidermotropic and dermal lymphocytic phenotypes and the dermal macrophage CD68+HLA-DR+ phenotype. In LS, the NBT reaction revealed evidence of superoxide production associated with CD68+HLA-DR+ cells. Expansion of CD8+CD57+ lymphocytes is associated with viral infections, autoimmune disease, malignancies, and transplantation and is suspected to be the result of chronic excessive antigen challenge. In these pathologic states, CD8+CD57+ lymphocytes (as terminally differentiated, antigen-specific T cells) participate in the suppression of cytolytic activity to limit tissue damage. In LS, activated macrophages and lymphocytes indicate persistent antigen-driven inflammation. LS's numerous CD8+CD57+ lymphocytes may be either the mediators or the consequence of its hallmark sclerosis.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

CD34 antigen is expressed in normal human skin on endothelium, in spindle cells located around adnexal structures, and in a subset of interstitial cells in the reticular dermis. CD34 expression has also been identified in a number of fibrohistiocytic neoplasms, such as dermatofibrosarcoma protuberans and solitary fibrous tumors of soft tissue. CD34 expression has not previously been described in sclerotic, or “plywood” fibromas. Here presented are three lesions from three patients, in which histologic examination revealed a well-circumscribed dermal nodule composed of spindled cells with focal nuclear pseudoinclusions. There was extensive fibrosis with hypocellular, storiform areas, characteristic of sclerotic fibroma. The spindled cells strongly expressed CD34, but not factor XIIIa or markers of melanocytic, neural, or muscular differentiation. A diagnosis of Cowden syndrome was considered in one of the cases. These cases provide evidence that CD34 expression can occur in sclerotic fibromas, either solitary or associated with Cowden syndrome. When diagnosing a sclerotic fibroma, one should comment in the report regarding the possibility of Cowden syndrome.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Two cases showing changes of sclerotic fibroma developed in association with an inflammatory process, especially folliculitis. The lesion in the first case showed a well-circumscribed, nonencapsulated nodule in the dermis, which consisted of a perifollicular fibrotic area and a peripheral sclerotic area. In addition to the usual findings of sclerotic fibroma, spindle cells were heavily infiltrated in a storiform and fascicular pattern around the degenerated hair follicle, suggestive of dermatofibroma. The lesion in the second case showed the typical findings of sclerotic fibroma in association with folliculitis and hair follicle remnants. Our observations suggest that solitary sclerotic fibroma of the skin may be a degenerated or sclerotic end stage of other fibrous conditions, such as dermatofibroma, and that it may be induced by inflammation, especially folliculitis.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Desmoplastic malignant melanoma (DMM) is a rare and locally aggressive variant of malignant melanoma, which is difficult to diagnose clinically and microscopically. A retrospective study of 21 DMM were collected during 7 years, representing 1.7% of melanomas. By comparing S-100 and hematoxylin and eosin (H & E) staining in DMM, we sought to determine whether S-100 staining offered a more accurate means of assessing dermal and neural invasion, tumor thickness, and peripheral margins. Eleven cases were excluded because the tumor extended past the deep margin. Six cases that were stained with S-100 showed a greater tumor thickness than by H & E (difference of 0.13 to 2.79 mm). In two cases, the tumor thickness was greater by using H & E than S-100, and there was no difference in the remaining two cases. Of the eight cases in which the peripheral margins were positive by S-100, neoplastic cells were only apparent at those margins in four cases when examined with H & E. The remaining two cases showed negative margins by both stains. Clinical follow-up was obtained from nine cases, and none had recurrence of melanoma. Particularly for hypocellular and amelanotic tumors, S-100 staining proved to be a valuable adjunct in determining the extent of the tumor at the peripheral margins.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The histologic features of regression may be found in some basal cell carcinomas (BCCs), and it is known that T-cell infiltrates have a significant role in host defense against this tumor. We examined 945 hair follicles (HFs) adjacent to 150 regressing BCCs of skin for the presence of inflammatory infiltrates and compared the results against 315 HFs in 50 samples of normal skin. Focal T-cell infiltrates localized mainly to the upper portion of the HFs were found in 14.5% of the follicles adjacent to regressing BCCs. A statistically significant increase of inflammation in HFs was observed in BCCs with active regression compared with BCCs with inactive and mixed regression (P < 0.05). An increase in the number of HFs involved by T lymphocytes was also found in regressing BCCs compared to normal skin ( P < 0.00005). These data suggest that the damage to the follicles is concordant with active regression of BCCs. We speculate that the immune-mediated regression of BCCs is not only specifically directed to the cells of the tumor but may also induce activated lymphocytes with cytotoxic capability to cross react with the follicular epithelium.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

There are glaring discrepancies in the microanatomical descriptions of cellulite in the literature. We revisited this common skin condition in women with a microscopic examination of 39 autopsy specimens. A control group consisted of 4 women and 11 men showing no evidence of cellulite. The lumpy aspect of the dermohypodermal interface appeared to represent a gender-linked characteristic of the thighs and buttocks without being a specific sign of cellulite. Incipient cellulite identified by the mattress phenomenon was related to the presence of focally enlarged fibrosclerotic strands partitioning the subcutis. Such strands possibly serve as a physiologic buttress against fat herniation limiting the outpouching of fat lobules on pinching the skin. These structures might represent a reactive process to sustained hypodermal pressure caused by fat accumulation. Full-blown cellulite likely represents subjugation of the hypertrophic response when connective tissue is overcome by progressive fat accumulation. Histologic aspects reminiscent of stretch marks are identified within the hypodermal strands, resulting in clinical skin dimpling.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Canine histiocytic proliferative disorders include reactive diseases such as cutaneous and systemic histiocytosis and neoplastic diseases such as cutaneous histiocytoma and localized and disseminated histiocytic sarcoma (malignant histiocytosis). Their etiology and pathogenesis are unknown. Canine cutaneous and systemic histiocytosis target the skin and subcutis and have similar clinical behavior. Systemic histiocytosis also affects other organ systems. Clinicopathologic and phenotypic features of canine cutaneous and systemic histiocytosis were examined in this study. Canine cutaneous (18 cases) and systemic (26 cases) histiocytosis were characterized by angiocentric, pleocellular accumulations consisting of CD1+, CD11c+, MHC II+, CD4+, and Thy-1+(CD90) activated dermal dendritic antigen-presenting cells (APC) with admixed CD3+, CD8+, TCR&agr;&bgr;+T lymphocytes, and neutrophils. Hence, canine cutaneous and systemic histiocytosis represent two clinical manifestations of a reactive proliferation of dermal dendritic cells. Cultures and special stains failed to identify infectious agents. Canine reactive histiocytoses respond to immunosuppressive therapy (cyclosporine A or leflunomide). Therefore, immunedysregulatory mechanisms are likely to be involved. Spontaneous reactive histiocytoses are frequently seen in dogs, and they constitute an excellent model to study pathologic mechanisms involved in reactive proliferations of dermal dendritic APC.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

c-kitprotooncogene encodes a type III transmembrane receptor kinase, the stem cell factor receptor, or KIT. The ligand of the KIT, stem cell factor, is a cytokine that stimulates mast cell growth and differentiation. We have studied immunohistochemically KIT expression in 23 canine mast cell tumors (MCTs), 10 histiocytomas, 5 malignant melanomas, and in 2 cell lines derived from mast cells (HMC-1, human and C2, canine). As expected, KIT was detected both in the human mast cell leukemia cell line (HMC-1) and in the canine mastocytoma cell line C2. In normal canine skin, KIT expression was confined to mast cells. All canine MCTs expressed KIT, although the intensity of the staining reaction varied considerably among the 23 neoplasms. Grade III tumors showed the highest expression of KIT, whereas grade I tumors showed the lowest expression of KIT. Two patterns of KIT expression were detected in mast cells. In normal canine mast cells and in some neoplastic mast cells, KIT appeared mainly on the cell membrane. However, in many canine MCTs, KIT is accumulated in the cytoplasm, usually near the cell nucleus. The meaning of these two patterns is not clear. Expression of KIT could not be detected immunohistochemically in any of the other neoplasias investigated. According to our results, it can be concluded that most, if not all, canine MCT express KIT. Furthermore, there is an inverse correlation between the degree of differentiation and the expression of KIT. Moreover, according to our results, KIT can be used as a reliable immunohistochemical marker for canine mast cells and undifferentiated mast cell tumors.

ISSN:0193-1091    

出版商:OVID    

年代:2000

数据来源: OVID