Papillary Tubular Adenoma of the Skin

A case of papillary tubular adenoma of the skin in a 31-year-old black man is reported. This lesion is also termed papillary eccrine adenoma, and it commonly occurs in the extremities.     

Eccrine hidrocystoma: two cases of Robinson and Smith types.

Two cases of eccrine hidrocystoma, one of which is a "classic" Robinson type and the other a Smith type, were reported. The walls of both cysts consisted mainly of two layers of flat or low cuboidal epithelial cells with eosinophilic cytoplasm. Immunostaining for S-100 protein was negative in the cells of the cyst wall of the Robinson type and only weakly positive in the inner luminal layer of the Smith type. Electron microscopically, the Smith type showed double-layered cuboidal lining and cell membrane interdigitations as junctions of neighboring cells without any characteristics of the secretory segment of sweat glands, indicating substantial similarity to those of the intradermal portion of the eccrine sweat duct.     

恶性小汗腺汗孔瘤的免疫组化和超微结构观察

目的观察细胞角蛋白在恶性小汗腺汗孔瘤中的表达,以期探讨其组织发生。方法采用免疫组化方法对６例恶性小汗腺汗孔瘤的石蜡包埋标本进行检测,并对其中２例进行透射电镜观察。结果绝大多数肿瘤细胞示３４βＥ１２阳性,部分肿瘤细胞（衬于导管样结构和囊状腔隙内的细胞）示３５βＨ１１、ＣＡＭ５．２和ＰＫＫ１阳性。电镜下可见肿瘤细胞胞质内管样结构。结论证实了恶性小汗腺汗孔瘤来源于小汗腺导管。同时提示,部分肿瘤细胞显示向小汗腺分泌部分化特征。     

Digital papular calcific elastosis: a histopathological, histochemical and ultrastructural study of 20 patients

In 1960, 5 patients were reported with a condition termed "degenerative collagenous plaques of the hands". Ultraviolet light and chronic pressure seem to be the inciting factors. Clinically, it is characterized by keratotic, translucent papules, in linear array, on the radial border of the hands. Histology shows hyperkeratosis and dermal elastosis. The current study documented the histopathological, histochemical and ultrastructural features of 20 patients with this condition and considered the differential diagnoses. The findings were in accordance with those of previous studies, but peculiar, basophilic elastotic masses (BEMs), were a prominent finding. Ultrastructurally, elastic tissue appeared in the form of degenerated non-fragmented and fragmented elastic fibres, degenerated fibres showing foci of increased density, with or without a fibrillar component and as amorphous, structureless material. BEMs arose almost exclusively from degenerated elastic tissue and contained calcium. Disintegrated collagen may be incorporated in the amorphous material and, subsequently, form a minor part of BEMs. Solar elastosis, and its variants, show some similarity to degenerative collagenous plaques of the hands, but lack the constant presence of these calcified angular elastotic masses. BEMs show resemblance to elastic globes, and elastotic bodies found in elastotic nodules of the anthelix and cartilage-hair hypoplasia. In the clinical setting of "degenerative collagenous plaques of the hands", BEMs seem to be unique and due to their extensive presence serve as a non-specific marker for this condition. Digital papular calcific elastosis therefore seems to be more appropriate nomenclature.     

An immunohistochemical and ultrastructural study of syringocystadenoma papilliferum

BACKGROUND: Syringocystadenoma papilliferum is a benign hamartomatous tumour of the skin. The histogenesis of this tumour is still controversial. There have been few reports regarding immunohistochemical investigations using only a limited range of antibodies and ultrastructural studies on this rare tumour. OBJECTIVES: To elucidate the immunohistochemical and ultrastructural properties of this tumour. METHODS: We investigated the immunohistological patterns of 12 different anticytokeratin (CK) antibodies and several other markers in five cases of this tumour, comparing them with the patterns in adult sweat glands. One of these cases was also evaluated ultrastructurally. RESULTS: The luminal columnar cells of the tumour were mostly positive for CK7 and more than 70% were positive for CK19. These cells showed the heterogeneous expression of CK1/5/10/14, CK14 and CK5/8. These patterns were also observed in the luminal cells in the secretory or the ductal portion of the adult sweat glands. The basal cuboidal cells of the tumour almost constantly expressed CK1/5/10/14, CK5/8, CK14 and CK7 (except for one case), similar to the patterns of basal cells in the transitional portion and myoepithelial cells in the sweat glands. However, the basal tumour cells expressed CK19 and vimentin heterogeneously, and alpha-smooth muscle actin focally (three cases). Ultrastructurally, the constituent epithelial cells were mainly divided into three types: luminal cells, basal cells and clear cells. The luminal tumour cells bore features of the secretory or ductal luminal cells of sweat glands, although they were somewhat immature in appearance. The basal tumour cells were fundamentally basaloid in nature. The clear cells were undifferentiated or primitive in appearance, suggesting stem or progenitor cell properties. Transitional forms between the clear cells and the other two cell types were also identified. CONCLUSIONS: The tumour epithelium was composed of several cell types demonstrating various developmental stages from the primitive clear cells to the basal cells demonstrating a tendency to differentiate toward basal cells in the apocrine transitional portion or myoepithelial lineage, or luminal cells toward the ductal or secretory epithelium. These results support the classical concept that syringocystadenoma papilliferum is a hamartomatous tumour that arises from pluripotent cells.     

Oral hairy leukoplakia in AIDS patients: an ultrastructural study

Hairy leukoplakia is a specific oral lesion associated with the opportunistic development of Epstein-Barr virus in the oral epithelium. It is now considered to be an early sign of HIV-induced immunosuppression. Four cases of oral hairy leukoplakia (OHL) from the lateral borders of the tongue of male AIDS patients were investigated by transmission electron microscopy. At the ultrastructural level, herpes-like viral particles were detected in the oral lesions of all cases. Indirect immunofluorescence performed on two cases showed the presence of EBV antigens in the nuclei and the cytoplasm of the infected epithelial cells. None of the specimens contained ultrastructural evidence of human papillomaviruses.     

Distinctive eosinophilic cytoplasmic inclusion bodies in melanocytic nevi: an immunohistochemical and ultrastructural study

Background: We sought to further determine the histochemical, immunohistochemical and ultrastructural properties of eosinophilic cytoplasmic inclusion bodies in melanocytic nevi. Methods: Skin specimens from four patients with a known diagnosis of conventional melanocytic nevus (3) or Spitz nevus (1) and containing intracytoplasmic eosinophilic inclusion bodies were selected. In addition, melanomas (25), Spitz nevi (10) and blue nevi (4) were examined to determine the frequency of the inclusions. Results: Inclusions tended to be located in multinucleated melanocytes with abundant vacuolated cytoplasm. In conventional (hematoxylin and eosin‐stained) sections, the degree of density and eosinophilia of intracytoplasmic inclusions varied with size. Periodic acid‐Schiff, Fontana and Congo red stains showed no reactivity. All bodies were immunoreactive for ubiquitin but negative for tyrosinase, keratin and vimentin. Ultrastructurally, inclusion bodies were non‐membrane bound, ranged from 4 to 7 µm, and were comprised of radiating filamentous structures with or without an electron‐dense core. Electron probe x‐ray microanalysis revealed no significant peaks. None of additional melanomas, Spitz nevi and blue nevi that were evaluated showed similar inclusions. Conclusions: The inclusion bodies described herein bear no resemblance to other cytoplasmic inclusion bodies previously described in melanocytic lesions. There is no discernible relationship to melanosomes by ultrastructural analysis. We postulate a relationship with dysfunction of ubiquitin‐mediated protein degradation occurring in melanocytes. Shon W, Wada DA, Gibson LE, Flotte TJ, Scheithauer BW. Distinctive eosinophilic cytoplasmic inclusion bodies in melanocytic nevi: an immunohistochemical and ultrastructural study.     

Androgenetic alopecia in males: a histopathological and ultrastructural study

Background  Androgenetic alopecia is a common cosmetic hair disorder, resulting from interplay of genetic, endocrine, and aging factors leading to a patterned follicular miniaturization. Microinflammation seems to be a potential active player in this process.
Aims  To study the histopathological and ultrastructural changes occurring in male androgenetic alopecia (AGA).
Patients/methods  Fifty-five subjects were included in this study (40 with AGA and 15 as normal age-matched controls). Skin biopsies from frontal bald area and occipital hairy area were subjected to histopathological examination, immunohistochemical staining for collagen I and ultrastructural study.
Results  The frontal bald area of patients showed highly significant increase in telogen hairs and decrease in anagen/telogen ratio and terminal/vellus hair ratio ( P  <   0.001). Perifollicular inflammation was almost a constant feature in early cases and showed a significant inverse correlation with perifollicular fibrosis ( P  =   0.048), which was more marked with thickening of the follicular sheath in advanced cases.
Conclusion  Follicular microinflammation plays an integral role in the pathogenesis of AGA in early cases. Over time, thickening of perifollicular sheath takes place due to increased deposition of collagen, resulting in marked perifollicular fibrosis, and sometimes ends by complete destruction of the affected follicles in advanced cases.     

Hairy leucoplakia—a clinical, histopathological and ultrastructural study in 33 patients

Thirty-three cases of hairy leucoplakia (HL) in HIV-positive patients were studied. The most frequent clinical presentation was the development of corrugated plaques on the lateral sides of the tongue without spiculations on the surface. In all biopsies, herpetic-type viral inclusions were found. In 12 out of 14 cases in whom an electromicroscopic study was carried out, only viral particles of the herpes group were found. Human papillomavirus (HPV) was not demonstrated, although by means of immunohistochemistry, positive labelling for HPV was found in 95% of the cases. The aetiopathological significance of these findings remains to be evaluated.     

Cutaneous ciliated cyst: a case report and histochemical, immunohistochemical, and ultrastructural study

A 19-year-old woman with a cutaneous ciliated cyst on her buttock is reported. Histological, histochemical, and electron microscopic studies revealed ciliated cells, mucinous cells showing merocrine secretion, and areas of squamous metaplasia in the cyst wall. This is the first case of cutaneous ciliated cyst that contained non-ciliated mucinous cells as a component.     

The inflammatory response in drug-induced acute urticaria: ultrastructural study of the dermal microvascular unit

BACKGROUND: Drug exposure is one of the main aetiologies of urticaria and represents the second most common cause in acute urticarias. Studies involving the ultrastructural aspects of urticaria are relatively rare in the literature. Most of the articles published report on skin biopsies of experimentally induced urticaria, and acute urticaria has been studied even less from a morphological point of view. OBJECTIVES: The aims of this study were to observe ultrastructural cell characteristics in five patients with drug-induced acute urticaria and possible aspects of the inflammatory skin response. METHODS: Clinical manifestations, light microscopy and transmission electron microscopy were evaluated. RESULTS: With light microscopy, a mild perivascular lymphocyte-monocyte infiltrate was observed with few neutrophils and dermal oedema in skin biopsies of five patients. With electron microscopy, a mild vascular dilatation was observed, with platelets in the lumen and several lymphocytes and dendritic cells close to the superficial dermal vessels. Some mast cells appeared normal, whereas others were granule-depleted. In some areas, mast cells, lymphocytes and satellite dendritic cells were closely associated, as well as some macrophages. A significant number of plasma cells, eosinophils and polymorphonuclear neutrophils were not observed; however, the presence of lymphocytes and macrophages was significant. The epidermis and the dermal-epidermal junction were preserved, except for a discrete oedema in keratinocytes. CONCLUSIONS: The ultrastructural aspect of drug-induced acute urticaria is similar to that observed in urticaria caused by Urtica dioica, intradermal histamine and cold urticaria. The presence of the cellular triad with mast cells, dendritic (or satellite) cells and lymphocytes suggests a functional interaction of these cells. These findings support the possible existence of mechanisms in the dermis that may participate in protective and/or injurious vasocentric immune reactions.     

Sweat gland adenoma with predominant myoepithelial differentiated features: case report and immunohistochemical study.

A 56-year-old man presented with a subcutaneous mass adjacent to the sternoclavicular joint region, which had predominant spindle-shaped myoepithelial cells and a small number of tubular or trabecular epithelial cells that resembled eccrine differentiation under a light microscope. Immunohistochemical studies showed positive staining for muscle-specific actin and vimentin in the myoepithelial cells, but staining was negative for S-100 protein and keratin. The tubular and trabecular epithelial cells stained positively for keratin, EMA and CEA. We believe that this rare tumor had the potential for biphasic differentiation and should be differentiated from other biphasic differentiated or mixed tumors in this site. Immunohistochemical staining was useful for diagnosis and differential diagnosis.     

Morphogenesis of the cornoid lamella: histochemical, immunohistochemical, and ultrastructural study of porokeratosis

To elucidate the morphogenesis of cornoid lamellae (CL) in porokeratosis, skin lesions of three cases of disseminated superficial actinic porokeratosis and a case of linear porokeratosis were examined. By N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide staining, SH groups were present in the living layer of the epidermis beneath CL and irregularly disappeared at the bottom of CL, whereas SS linkages appeared in dyskeratotic cells in the living layer and in the irregularly shaped cell membranes of the horny cells. Epidermis beneath CL showed an increased and irregular involucrin expression. Ultrastructurally, the living keratinocytes contained many cytoplasmic vacuoles and had a smaller number of lamellar bodies than normal. Intercellular lamellar sheets were incompletely formed. The dyskeratotic cells and the lower horny cells contained many small vacuoles but formed a marginal band. The horny cells of CL also formed a marginal band and, further, a keratin pattern. CL may be formed by hyperproliferative atypical kertatinocytes which keratinize rapidly and irregularly and show defective desquamation due to the paucity of intercellular lamellar sheets.     

Expression of CA 50 in normal human skin: comparative study of CEA and CA 19-9.

Normal skin specimens from different body sites were estimated for the expression of CA 50 in comparison with CA 19-9 and CEA. Expression of CA 50 and CA 19-9 was observed in the ductal system and a small part of the secretory portion of eccrine units, but never in any other skin components including apocrine units. CEA was expressed on the ductal and a small part of the secretory portion of apocrine units as well as on those of eccrine units. However, the expression pattern and intensity in eccrine units were different from those of CA 50 or CA 19-9. We concluded that CA 50 was strongly expressed in the normal ductal system of eccrine units and hence could be standardized to stain the eccrine ductal portion and that immunohistochemical comparative studies with CA 19-9 or CEA might be a good methodological technique for discriminating an eccrine or apocrine origin for some skin disorders.     

Alopecia mice derived from albino ddY mice: breeding, histological and ultrastructural studies

Sparse-haired (SH) mice arose spontaneously in a stock of sib-mated albino ddY mice. Hair loss in the skin of SH mice begins at 3 weeks of age and progresses with age. On the basis of breeding studies between SH mice and albino ddY mice, the phenotype of SH mice is identified as autosomal recessive inheritance. Histological examination shows that numerous pilary canals begin to widen and the outer root sheath becomes thin at 1 week of age. The inner root sheath and the hair were separated. Ultrastructural examination reveals that electron dense materials which formed coalesced and irregularly coiled chains are seen at the level of firm attachment of the hair to its inner root sheath. At the level of hair and inner root sheath separation, linear materials with high electron density are observed in the exocuticle of the hair cuticle. These results suggest that the appearance of electron dense materials is closely related to the mechanism of hair loss in SH mice and SH mice may be useful as an animal model in human hypotrichosis.     

Myofibroblastic differentiation in atypical fibroxanthomas occurring on sun-exposed skin and in a burn scar: an ultrastructural and immunohistochemical study

Herein, we report the investigation of two cases of atypical fibroxanthoma (AFX). One AFX developed within actinically damaged skin, as is typical, while the other developed within a burn scar within non-sun-exposed skin. The two tumors showed almost identical histopathological, immunohistochemical and ultrastructural features. The tumors were composed of pleomorphic spindled, epithelioid, multinucleated and bizarre cells with enlarged atypical nuclei. Most tumor cells expressed vimentin and about 50% expressed CD10. Some tumor cells also expressed α-smooth muscle actin and CD68. However, there was no expression of cytokeratins, p63, S-100 protein, melan-A, HMB 45, desmin, epithelial membrane antigen or CD34. Ultrastructurally, the tumor cells contained myofilaments with dense patches but lacked plasmalemmal caveolae and basal lamina. The most prominent finding was the identification of fibronexus junctions. In addition, there were tumor cells containing numerous lysosomal granules. In conclusion, we clearly showed myofibroblastic differentiation in AFX by electron microscopy. We report also a case of AFX directly developing within a burn scar in the absence of actinic damage.     

Intrinsic aging vs. photoaging: a comparative histopathological,immunohistochemical, and ultrastructural study of skin

Cutaneous aging is a complex biological phenomenon affecting the different constituents of the skin. To compare the effects of intrinsic and extrinsic aging processes, a total of 83 biopsies were collected from sun-exposed and protected skin of healthy volunteers representing decades from the 1st to the 9th (6-84 years of age). Routine histopathology coupled with computer-assisted image analysis was used to assess epidermal changes. Immunoperoxidase techniques with antibodies against type I and type III collagens and elastin were used to quantitatively evaluate changes in collagen and elastic fibers and their ultrastructure was examined by transmission electron microscopy. Epidermal thickness was found to be constant in different decades in both sun-exposed and protected skin; however, it was significantly greater in sun-exposed skin (P = 0.0001). In protected skin, type I and III collagen staining was altered only after the 8th decade, while in sun-exposed skin the relative staining intensity significantly decreased from 82.5% and 80.4% in the 1st decade to 53.2% and 44.1% in the 9th decade, respectively (P = 0.0004 and 0.0008). In facial skin the collagen fiber architecture appeared disorganized after the 4th decade. The staining intensity of elastin in protected skin significantly decreased from 49.2% in the 1st decade to 30.4% in the 9th decade (P = 0.05), whereas in sun-exposed skin the intensity gradually increased from 56.5% in the 1st decade to 75.2% in the 9th decade (P = 0.001). The accumulated elastin in facial skin was morphologically abnormal and appeared to occupy the areas of lost collagen. Collectively, the aging processes, whether intrinsic or extrinsic, have both quantitative and qualitative effects on collagen and elastic fibers in the skin.