Sarcomatoid renal cell carcinoma is an uncommon tumor that has to be distinguished from renal carcinosarcoma. We have described three cases of sarcomatoid renal cell carcinoma showing different clinical and light microscopic features. An ultrastructural study of the tumor cells from the sarcomatoid area revealed frequent desmosomal junction, confirming the epithelial nature of the neoplasm. All three cases showed an aggressive clinical course and tended to invade adjacent organs or tissues. We believe that an histological and immunohistochemical examination in conjunction with an electron microscopic examination are necessary to diagnose sarcomatoid renal cell carcinoma.
Carcinoma, Renal Cell* ; Carcinosarcoma* ; Desmosomes ; Microscopy, Electron

Accurnulation of keratinized cells within the infundibulum of pilosebaceous canal is important in the pathogenesis of acne. Light and electron microscopic study of experimentally induced comedones, from the rabbit's external ear canal, was performed to define the earIy morphologic changes within and around the epithelial lining of the comedones. In light microscopic observation, early comedone was composed of loose cohesive horny cells and late comedone was composed of a mixture of loose and tight cohcsive horny cells. Cohesion between horny cells occured, in eIectron microscopic study, in two different ways: initially, by the persistence of desmosomes; later, and to a lesser extent, by tight junctions, which tightly bound the horny cells together. Multiple lipid droplets within the horny ceIls and a gradual decrease in the numbrane coating granules were observed.
Acne Vulgaris ; Desmosomes ; Ear Canal ; Tight Junctions

Well-differentiated papillary mesothelioma (WDPM) of the peritoneum is considered to be a distinct subtype of peritoneal mesothelioma and has mostly behaved in a benign fashion. We report a case of WDPM in a 48-year-old-woman. It was incidentally found during a hysterectomy for a uterine cervical carcinoma. Grossly, the tumor was composed of multiple peritoneal nodules, measuring up to 2 cm. Microscopically, the nodules showed well-developed papillae lined by a single layer of cuboidal mesothelial cells. Immunohistochemical staining revealed a positive reaction for cytokeratin and a negative reacion for carcinoembryonic antigen and Leu-M1. Ultrastructurally, the tumor cells showed numerous long, slender microvilli and desmosomes.
Carcinoembryonic Antigen ; Desmosomes ; Hysterectomy ; Keratins ; Mesothelioma* ; Microvilli ; Peritoneum*

We have observed the ultrastructures of Langerhans cell in the normal limbal eonjunctiva by electron microscopy and expression of HLA-DR antigen by peroxidase-antiperoxidase(PAP) method in the normal limbal conjunctiva. In electron microscope, Langerhans cell had no junctional complex like desmosome, irregular and invaginated nucleus, and characteristic Birbeck granlues in the cytoplasm. In PAP method, HLA-DR-positive cells were found in basal or suprabasal layer of conjunctival epithelium as dendritic form.
Conjunctiva* ; Cytoplasm ; Desmosomes ; Epithelium ; HLA-DR Antigens* ; Microscopy, Electron

Osteofibrous dysplasia (OFD)-like adamantinoma is a rare skeletal tumor that is characterized by the predominant OFD-like pattern with scattered epithelial nests. Adamantinoma shares clinical features (the majority of lesions in the tibia and the prevalent age group), radiologic findings (radiolucency with sclerotic shadow), and pathologic similarities (particularly the presence of scattered cytokeratin-positive stromal cells) with OFD. We describe a case of OFD-like adamantinoma. Epithelial cell nests express the epithelial membrane antigen, pancytokeratin, CK14, and collagen type IV. Ultrastructurally, the oval to spindle cells in the epithelial foci had abundant tonofilaments, and well-formed desmosomes with dense plaques, of which well preserved desmosomes are demonstrated for the first time in OFD-like adamantinoma. These immunohistochemical and ultrastructural findings further support that the origin of epithelial cells of classic and OFD-like adamantinoma are epithelial cells transformed from fibroblastic cells in the proliferating osteofibrous tissue.
Adamantinoma* ; Collagen Type IV ; Desmosomes ; Epithelial Cells ; Fibroblasts ; Fibroma, Ossifying ; Immunohistochemistry ; Intermediate Filaments ; Mucin-1 ; Tibia

We have experienced two cases of extramammary Paget's disease. The first case was a 68-year-old male who showed erythematous, crusted, oozing, eczematoid patches on the scroturn, penile root and pubic area, and verrucous plaque on the left pubic area of 5 years' duration. The second case was a 60-year-old male who showed erythematous, oozing, hyperkeratotic plaque and nodular mass on the scrotum of 4 years' duration. In electron microscopic findings of the first case, the Paget's cells was suggested to be formed by pleuripotential germinative cells; well developed microvilli, numerous electron lucent secretory granules, a few electron dense granules, apocrine type secretion and well developed desmosome.
Aged ; Desmosomes ; Humans ; Male ; Microvilli ; Middle Aged ; Paget Disease, Extramammary ; Scrotum ; Secretory Vesicles

A case of hypertrophic lichen planus was reported and the literature reviewed. A 69-year-old widowed woman displayed generaIized discrete, multiple, round, various sized, flat-topped, hypertrophied papules and nodules on the abdomen, trunk and four extrimies for 42 years. An electron microscopic finding revealed widespread breakdown and thickening of the basal lamina at the dermo-epidermal junction and a degenerating change of the desmosomes. No particular intran uclear particles or bodies were discovered. We suggest that emotional factors and autoimmune mechanism might be the cause of the eruption in this case.
Abdomen ; Aged ; Basement Membrane ; Desmosomes ; Female ; Humans ; Lichen Planus* ; Lichens* ; Widowhood

BACKGROUND: Desmocollins (Dsc) are calcium-dependent transmembrane glycoproteins of desmosomes that are important in the junction complex of epidermis and maintain structural integrity of the skin from external stressors. Among three Dscs (Dsc 1, 2, 3), Dsc 1 and 3 are distributed on skin. OBJECTIVE: The purpose of this study was to observe the Dsc 1 distribution pattern on the skin and oral mucosa during fetal development. METHODS: Skin was obtained from the sole and scalp of 33 fetuses, ranging from 10 to 37 weeks of gestational age. Immunohistochemical staining was performed on the paraffin-embedded tissue using a Dsc 1 monoclonal antibody. RESULTS: Dsc 1 was expressed in the suprabasal layer but not in the basal layer of the epidermis of the sole at the 10th week of gestation. Thereafter, Dsc 1 expression further increased in the suprabasal layer with initiation of stratification and increased gradually in the granular layers of the sole and scalp epidermis. Dsc 1 was strongly expressed in the superficial layer of the infundibulum and inner root sheath of the hair follicle but was not expressed in the sebaceous cells or other hair components. The eccrine duct epithelium was focally and weakly positive for Dsc 1 expression. Furthermore, Dsc 1 was not expressed in oral mucosa, although the oro-cutaneous portion was strongly expressed in the superficial layer. CONCLUSION: Dsc 1 was strongly expressed in the suprabasal cells of the epidermis during fetal skin development, and expression increased gradually in the granular layer and inner root sheath of the hair follicle. However, Dsc 1 was not expressed in basal cells or in oral mucosa. Dsc 1 may play a role in the maintenance of epithelial integrity as part of desmosomes.
Desmocollins ; Desmosomes ; Epidermis ; Epithelium ; Fetus ; Gestational Age ; Glycoproteins ; Hair ; Hair Follicle ; Mouth Mucosa ; Pregnancy ; Scalp ; Skin

Pemphigus vulgaris is an autoimmune blistering disease of the skin and mucous membranes. It is characterized, histologically, by intraepidermal blisters, and immunopathologically, by the bound and circulating IgG directed to the epithelial desmosomes. In the majority of patients, painful mucous membrane erosions, especially in the oral cavity, are the presenting sign. The hair follicle is also a preferential target for pemphigus autoantibodies as the desmosomal proteins are overexpressed in follicular epithelium. We herein report a case of pemphigus vulgaris presenting with normal anagen effluvium.
Autoantibodies ; Blister ; Desmosomes ; Epithelium ; Hair Follicle ; Humans ; Immunoglobulin G ; Mouth ; Mucous Membrane ; Pemphigus* ; Skin

BACKGROUND: Matrix metalloproteinases (MMPs) participate in extracellular matrix degradation and may play an important role in basal membrane damage in many dermatologic diseases. Recent studies implicated the importance of MMP-9 in the pathogenesis of bulla formation of bullous pemphigoid (BP). Various autoimmune bullous diseases are strongly associated with desmosome or hemidesmosome pathologies, and show an increased level of lesional MMP and exposed autoantigens from these structures. OBJECTIVE: This study evaluated the level of MMP-2, -3, and -9 in three types of autoimmune bullous disease [BP, pemphigus vulgaris (PV), pemphigus foliaceus (PF)] with the aim of investigating the role of MMPs in the pathogenesis of autoimmune bullous diseases. METHODS: Sample specimens were obtained from skin lesions of patients with BP (n=12), PV (n=10), and PF (n=12), and from normal controls (n=8). The immunohistochemical expression of MMP-2, -3, and -9 was analyzed and serum levels of MMP-2, -3, and -9 were measured by enzyme-linked immunosorbant assay (ELISA). The results were analyzed with reference to graded levels of clinical severity. RESULTS: Expression of dermal MMP-2, -3, and -9 were increased in BP, PV, and PF (p=0.036, 0.022, and 0.015, respectively). However, decreased expression of the three MMPs in the epidermis of skin lesions may have resulted from epidermal destruction. ELISA-determined serum levels of MMP-2, -3, and -9 increased in BP, PV and PF. Interestingly, MMP-2 was significantly increased in the sera of BP patients (p=0.015), consistent with the previous studies concerning the role of gelatinase (MMP-2 and -9) in the pathogenesis of BP. In BP patients, clinical severity was proportional to increased levels of MMP-2 in both skin lesions and and sera. CONCLUSION: The increased expression of MMP-2, -3, and -9 in skin lesions and sera may reflect the involvement of these enzymes in the mechanism of bulla formation in autoimmune bullous diseases including BP. In addition, expression of MMP and clinical severity may be closely connected.
Autoantigens ; Blister ; Desmosomes ; Epidermis ; Extracellular Matrix ; Gelatinases ; Hemidesmosomes ; Humans ; Matrix Metalloproteinases ; Membranes ; Pemphigoid, Bullous ; Pemphigus ; Skin