Portion Of Eccrine Sweat Glands Research Articles

Eccrine Porocarcinoma of the Face is a Great Imitator With Aggressive Behavior.

IntroductionEccrine porocarcinoma (EPC) is a rare subtype of non-melanoma skin cancer developing in the intraepithelial portion of eccrine sweat glands. It is branded with a highly metastatic potential and increased rate of local recurrence after treatment. EPC showcased a trend of developing on the extremities, with presentation on the face sparse.ObjectivesAim of the study was to evaluate the frequency, clinical features, and course of this malignancy presented on the face.MethodsA retrospective review of the skin cancers excised between January 2010 and June 2021 was conducted in the plastic surgery department of a tertiary hospital. Patients were included in the study if EPC on the face was histologically confirmed. A prospectively maintained clinic database and the pathological reports were used to collect data.Results4 EPC cases on the face out of 3984 confirmed skin cancers were identified. None of the cases was suspected clinically, but the diagnosis was established following the histopathologic examination. An aggressive postoperative behavior was confirmed in 2 cases.ConclusionsThe variance in the clinical presentation and the non-specific characteristics are perplexing clinical diagnosis, with the histopathologic examination representing the current standard for confirmation. Early diagnosis and adequate surgical resection are recommended as treatment cornerstones. Clinical awareness ought to be raised and a definitive treatment protocol be established for optimized results.

Étude clinique et histopronostique de 50 cas de porocarcinome eccrine

Eccrine porocarcinoma is a rare cutaneous tumor arising from the intra-epidermal portion of eccrine sweat glands, the acrosyringium. Histoprognostic studies in large series are rare. Herein, we report a retrospective study of 50 cases. Fifty cases of porocarcinoma were retrieved from a histopathological register. Each histopathological sample was evaluated for the following criteria: presence or absence of dermal invasion, pattern of the infiltrative component (pushing or infiltrative), tumor thickness, lymphovascular emboli, perineural invasion and mitotic index. Clinical data and outcome were also retrieved for each patient. Mean patient age was 77 years (range: 43-99 years). The mean duration of progression prior to diagnosis was 4 years and 5 months. The 2 most common skin locations were the head (38%) and lower limbs (20%). The lesions showed no specific distinctive clinical features. Six cases were in situ, and 44 were invasive (23 with limited infiltration and 20 with scattered infiltration). Mean tumor thickness was 4.37 mm (range: 0.5 to 20 mm). Neighboring or remote epidermal involvement was noted in 7 cases. Lymphovascular emboli were observed in 3 cases. No cases of neurotropism were observed. The average mitotic index was 6.5 mitoses/high power (×400) field. A mean follow-up of 24.3 months was available for 48 patients. Local recurrence was noted in 5 patients, 4 of whom died from visceral metastases. These 5 cases showed no distinctive clinical features, a scattered pattern of the invasive component, cuticular cells, significant tumor thickness (mean 12.8 mm, range 9-20 mm), and an elevated mitotic index. Two histopathological criteria were significantly associated with a metastatic outcome: scattered pattern of the dermal invasive component (P=0.04) and significant tumor thickness, above 10mm (P<0.01). Porocarcinoma is a tumor without any particular clinical criteria to distinguish it from squamous cell carcinoma. The architecture of the invasive component and tumor thickness constitute 2 important histoprognostic criteria.

Eccrine porocarcinoma: a case report.

Eccrine porocarcinoma is an extremely rare malignancy of the eccrine sweat gland. It is believed to arise from the intra-epithelial portion of eccrine sweat glands. It can either arise de novo or it can develop in a long standing eccrine poroma. It often occurs in the elderly, with the mean age of occurrence being 67 years. The tumour favours extremities, particularly the legs and feet. The propensity to form multiple cutaneous metastases is an unusual feature of eccrine porocarcinoma. It is also associated with visceral metastasis, resulting in death. An early diagnosis and prompt treatment are thus essential, owing to the aggressive behaviour of the tumour. Keeping in view its rarity of occurrence, we are hereby presenting a case of eccrine porocarcinoma which occurred in a 55-year-old female.

Expression and localization of the vascular endothelial growth factor and changes of microvessel density during hair follicle development of Liaoning cashmere goats

Vascular endothelial growth factors (VEGFs) play important roles in neovascularization, tissue development, and angiogenesis. In this study, changes in VEGF expression patterns and microvessel density (MVD), and their correlations, were investigated during hair follicle development in epidermal appendages of Liaoning cashmere goats. Polyclonal antibodies to VEGF and microvessels were used for monthly immunohistochemical examinations of normal skin specimens from adult female goats for one year. VEGF was expressed in the hair bulb of primary and secondary hair follicles, the outer and inner root sheaths, sebaceous glands (ductal and secretory portions), eccrine sweat glands (ductal and secretory portions), and the epidermis. Abundant expression of VEGF was observed in the follicular basement membrane zone surrounding the bulb matrix and in ductal and secretory portions of eccrine sweat glands. The change in VEGFs in primary hair follicles showed a bimodal pattern, with the first peak observed from March to May, and the second in August. Maximal expression in secondary hair follicles occurred in May and August. Therefore, VEGF expression in primary and secondary hair follicles is synchronized throughout the year, and is correlated to hair development. In the later telogen and anagen phases, VEGF expression was higher in the secondary, compared to the primary, hair follicle. Changes in MVD also showed a bimodal pattern with peaks in May and August. VEGF expression and MVD showed moderate and strongly positive correlation in the primary and secondary hair follicles, respectively. Therefore, MVD and VEGF are closely related to the processes involved in hair cycle regulation.

Telocytes in human skin – are they involved in skin regeneration?

Telocytes (TCs), a particular interstitial cell type, have been recently described in a wide variety of mammalian organs (www.telocytes.com). The TCs are identified morphologically by a small cell body and extremely long (tens to hundreds of μm), thin prolongations (less than 100 nm in diameter, below the resolving power of light microscopy) called telopodes. Here, we demonstrated with electron microscopy and immunofluorescence that TCs were present in human dermis. In particular, TCs were found in the reticular dermis, around blood vessels, in the perifollicular sheath, outside the glassy membrane and surrounding sebaceous glands, arrector pili muscles and both the secretory and excretory portions of eccrine sweat glands. Immunofluorescence screening and laser scanning confocal microscopy showed two subpopulations of dermal TCs; one expressed c-kit/CD117 and the other was positive for CD34. Both subpopulations were also positive for vimentin. The TCs were connected to each other by homocellular junctions, and they formed an interstitial 3D network. We also found TCs adjoined to stem cells in the bulge region of hair follicles. Moreover, TCs established atypical heterocellular junctions with stem cells (clusters of undifferentiated cells). Given the frequency of allergic skin pathologies, we would like to emphasize the finding that close, planar junctions were frequently observed between TCs and mast cells. In conclusion, based on TC distribution and intercellular connections, our results suggested that TCs might be involved in skin homeostasis, skin remodelling, skin regeneration and skin repair.

Metastatic eccrine porocarcinoma: report of a case and review of the literature

Eccrine porocarcinoma (EPC) is a rare type of skin cancer arising from the intraepidermal portion of eccrine sweat glands or acrosyringium, representing 0.005-0.01% of all cutaneous tumors. About 20% of EPC will recur and about 20% will metastasize to regional lymph nodes. There is a mortality rate of 67% in patients with lymph node metastases. Although rare, the occurrence of distant metastases has been reported.We report a case of patient with EPC of the left arm, with axillary nodal involvement and subsequent local relapse, treated by complete lymph node dissection and electrochemotherapy (ECT).EPC is an unusual tumor to diagnose. Neither chemotherapy nor radiation therapy has been proven to be of clinical benefit in treating metastatic disease. Although in the current case the short follow-up period is a limitation, we consider in the management of EPC a therapeutic approach involving surgery and ECT, because of its aggressive potential for loregional metastatic spread.

Stimulation of keratinocyte differentiation – a new role for the vanilloid receptor subtype 1 (VR1/TRPV1)?

Vanilloids and endogenous cannabinoids mediate their actions via the vanilloid receptor subtype 1 (VR1/TRPV1), a non‐selective cation channel, which is widely distributed in the central and peripheral nervous system. Only recently, VR1 has been shown to be expressed in keratinocytes in vitro and in vivo. However, a precise description of VR1 localization in epithelial cells was missing. To determine this, we investigated VR1‐immunoreactivity as well as mRNA and protein expression in a series of biopsies from normal, diseased, and capsaicin‐treated human skin. VR1 was found in epidermal keratinocytes, the inner root sheet and the infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts, and the secretory portion of eccrine sweat glands upon immunohistochemistry, RT‐PCR and Western blot analysis. Interestingly, in diseased skin such as prurigo nodularis, psoriasis vulgaris, and atopic dermatitis, VR1 expression in keratinocytes correlated with the degree of epidermal differentiation. Enhanced VR1 immunoreactivity and protein content was found in prurigo nodularis in which epidermal keratinocytes are highly differentiated. Under effective capsaicin therapy of prurigo nodularis, the epidermis thinned and the distribution pattern of VR1 on epidermal keratinocytes normalized. In psoriasis vulgaris, a disease with disturbed epidermal differentiation, less intense immunostaining for VR1 was observed. This could be confirmed by western blot analysis showing less VR1 protein amount in comparison to prurigo nodularis although histologically both showed a thickened epidermis. In atopic dermatitis, which is characterized by a moderate epidermal hyperplasia only and regular differentiated keratinocytes, VR1 immunoreactivity was unchanged in comparison to normal skin. These findings suggest that VR1 may contribute to regular differentiation of keratinocytes. VR1 activation opens non‐selective cation channels with high permeability to calcium, a ion that is crucially important for the synthesis of cornification proteins such as involucrin, fillagrin and loricrin. The role of VR1 in other epithelial cells of appendage structures remains to be determined. In summary, VR1 is widely distributed in the skin suggesting a central role for this receptor not only in nociception but also maturation and function of epithelial cells.

Expression of vanilloid receptor subtype 1 (VR1/TRPV1) in the skin – implications for neurogenic inflammation and nociceptive sensations

The vanilloid receptor subtype 1 (VR1/TRPV1) is a non‐selective cation channel that binds the vanilloid capsaicin and endogenous cannabinoids. In human skin, VR1 has recently been shown to be expressed by keratinocytes in vitro and in vivo. To determine a precise localization of VR1 in other cutaneous compartments in particular cutaneous nerve fibres, we investigated VR1 immunoreactivity as well as mRNA and protein expression in a series of normal and capsaicin‐treated human skin. VR1 immunoreactivity could be observed in cutaneous sensory nerve fibres, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts and the secretory portion of eccrine sweat glands. Upon RT‐PCR and Western blot, the expression of VR1 was confirmed in primary mast cells and keratinocytes from human skin. During capsaicin therapy, VR1‐receptor distribution was unchanged, while a reduction of neuropeptides (substance P, calcitonin gene‐related peptide) was observed in nerve fibres. After cessation of capsaicin therapy, neuropeptides re‐accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a central role for this receptor, e.g. in nociception and inflammation.

Expression of vanilloid receptor subtype 1 in cutaneous sensory nerve fibers, mast cells, and epithelial cells of appendage structures.

The vanilloid receptor subtype 1 (VR1)/(TRPV1), binding capsaicin, is a non-selective cation channel that recently has been shown in human keratinocytes in vitro and in vivo. However, a description of VR1 localization in other cutaneous compartments in particular cutaneous nerve fibers is still lacking. We therefore investigated VR1 immunoreactivity as well as mRNA and protein expression in a series (n = 26) of normal (n = 7), diseased (n = 13) [prurigo nodularis (PN) (n = 10), generalized pruritus (n = 1), and mastocytosis (n = 2)], and capsaicin-treated human skin (n = 6). VR1 immunoreactivity could be observed in cutaneous sensory nerve fibers, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and the infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts, and the secretory portion of eccrine sweat glands. Upon reverse transcriptase-polymerase chain reaction and Western blot analysis, VR1 was detected in mast cells and keratinocytes from human skin. In pruritic skin of PN, VR1 expression was highly increased in epidermal keratinocytes and nerve fibers, which was normalized after capsaicin application. During capsaicin therapy, a reduction of neuropeptides (substance P, calcitonin gene-related peptide) was observed. After cessation of capsaicin therapy, neuropeptides re-accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a major role for this receptor, e.g. in nociception and neurogenic inflammation.

Immunohistochemical localization of activated EGF receptor in human eccrine and apocrine sweat glands.

Epidermal growth factor (EGF) is secreted into sweat from secretory cells of human sweat glands. The function of EGF in sweat is poorly understood. The biological function of EGF is exerted by the binding of EGF to the receptor (EGFR) and its activation. Therefore, we immunohistochemically localized the activated form of EGFR in human eccrine and apocrine sweat glands to assess the functional importance of the EGF-EGFR system in human sweat glands. Frozen sections of human skin were stained with a monoclonal antibody (MAb) specific for tyrosine-phosphorylated (activated) EGFR and with an MAb that stains both activated and non-activated EGFR. In the secretory portion of eccrine sweat glands, nuclei of the secretory cells were stained with the anti-activated EGFR MAb. In coiled and straight portions of eccrine sweat ducts, nuclei of luminal and peripheral cells were stained with the antibody specific for activated EGFR. Luminal cell membranes and luminal cytoplasm of inner ductal cells possessed non-activated EGFR. In the secretory portion of apocrine sweat glands, activated EGFRs were present in cytoplasm and nuclei of secretory cells. These data suggest that EGF, already known to be present in the cytoplasm of secretory cells in eccrine and apocrine sweat glands, activates EGFR in the nuclei of secretory cells themselves in an intracrine manner. Because ductal cells do not express EGF, EGF in the sweat secreted from the secretory cells should activate EGFR in the ductal cells in a paracrine manner. (J Histochem Cytochem 49:597-601, 2001)

The Appearance, Density, and Distribution of Merkel Cells in Human Embryonic and Fetal Skin: Their Relation to Sweat Gland and Hair Follicle Development

The density and distribution of Merkel cells in human embryonic and fetal skin were studied using an immunolabeling technique on epidermal and dermal sheets obtained by ethylenediamine tetraacetic acid separation. Merkel cells were identified by the known cytokeratin markers CK20 and CK18. Merkel cells showed CK20 immunoreactivity as early as 56 d estimated gestational age (EGA) in the palmar epidermis (133.11 +/- 44.27 cells/mm2). The density increased rapidly, reaching a maximum of more than 1400 cells/mm2 at 80-90 d EGA. At this stage, the cells became distributed along the primary epidermal ridges. In the palmar epidermis of fetuses older than 100 d EGA, the distribution of Merkel cells showed the same pattern, but the density then decreased gradually. Merkel cells were not observed in ductal and glandular portions of eccrine sweat glands. In the epidermal sheets of hairy skin, a few cells were first seen in the fetus at 75 d EGA. At 100 d EGA, only a few Merkel cells were observed, mostly in the hair pegs and bulbous hair pegs. In the older fetus, ring-like arrangements and aggregates of Merkel cells were prominent in the infundibulum and bulge of hair follicles, respectively. Merkel cells were both globular and dendritic in shape. The ratio of dendritic to globular cells increased gradually until the period of highest Merkel cell density in both the glabrous and hairy skin. All Merkel cells located in the dermis were globular in shape. In accord with the results obtained, we postulate that Merkel cells may have some functional role in the formation and proliferation of eccrine sweat glands and hair follicle anlagen in developing skin.

Electron microscopic observation of the transitional portion in the human eccrine sweat gland.

The transitional portion in human eccrine sweat glands was observed by transmission electron microscope (TEM). The transitional portion, consisting of columnar epithelial cells (columnar cells) and basal cells, formed a very short segment about 25 to 50 microns in length. The portion was abruptly connected to the secretory segment, and shifted to the excretory duct without marked ultrastructural changes. The columnar cells were morphologically characterized by small apical vesicles as reported in previous reports. Considering the frequency of the mitosis of the columnar cells, the transitional portion seemed to be one of the areas of cell proliferation in the gland. Basal cells were sparse in the region connecting the secretory segment, but dense near the duct. Basal cells in the secretory segment side of the transitional portion, containing thin microfilament-bundles in the infranuclear cytoplasm, were considered to be immature myoepithelial cells. On its ductal side, however, the basal cells showed morphological profiles similar to ductal peripheral cells. These findings suggest that the differentiation of myoepithelial cells occurs in the transitional portion of eccrine sweat glands.

Dispersed Cell Culture of Human Sweat Duct Cells under Serum‐free Conditions

Human eccrine gland duct cells were successfully cultured using a serum-free medium, K-GM medium. Eccrine sweat ducts were isolated from dispase treated skin specimens from palms or soles. After treatment of the isolated ducts with trypsin and EDTA, dispersed cells were cultured in K-GM medium. In primary cultures, small colonies were seen 3 to 4 days after inoculation. Then the cells rapidly proliferated and formed large colonies with a paving stone-like cell arrangement. During the culture, small dome shaped areas were sometimes formed in the centers of colonies. Cultures multiplied for a maximum of 7 passages. The plating efficiencies of the 1st to 6th passage cells were about 20% to 30%. Immunocytochemically, cultured cells were positively stained with anti-carcinoembryonic antigens, K8.37 and K8.13, but not with anti-S100 protein, anti-HLA-DR, 34 beta B4, or PKK3. An electron micrograph of the cultured cells showed a multilayer of flattened cells linked by desmosomes. These results indicate that the cultured cells possessed the staining properties compatible with those of the ductal portion of eccrine sweat glands. No contamination by other mesenchymal cells, such as fibroblasts, was seen during the culture.

Anti-D47: a monoclonal antibody reacting with the secretory cells of human eccrine sweat glands.

Anti-D47 is a monoclonal antibody reacting with a surface antigen of human cortical thymocytes (different from the T6 antigen). It was prepared by immunization of mice with human thymocytes. The known cross-reactivity of monoclonal antibodies prepared against thymic cells with skin components prompted us to test anti-D47 on human skin as well as animal tissues. No labelling was observed on animal tissues. On human skin, anti-D47 was found to react with the secretory portion of eccrine sweat glands (ESG), i.e. with a cytoplasmic antigen of the secretory cells lining the deep portion of ESG glomeruli. No labelling was observed on apocrine sweat glands or on the excretory portion of ESG. Anti-D47 was also tested on histologically proven extramammary (vulvar) Paget's disease and basal cell epitheliomas: no staining of the neoplastic cells was observed. Anti-D47 appears to be an immunological marker of the secretory cells of human ESG and a new tool for the investigation of human sweat gland pathology.

Ultrastructure of eccrine cystadenoma. A case report

A case of eccrine cystadenoma was studied by electron microscopy. The tumor showed two types of cells, luminal and basal cells. The cells lacked the characteristics of the secretory segment of the sweat glands. The features of the luminal cells are similar to those of the intradermal portion of the eccrine sweat duct. In some areas, the lesion showed features characteristic of apocrine gland structure. Nuclear bodies were very frequent. The ultrastructural findings of eccrine cystadenoma support an origin from the ductal portion of eccrine sweat glands. (<i>Arch Dermatol</i>115:1217-1221, 1979)

Ultrastructure of Eccrine Cystadenoma

A case of eccrine cystadenoma was studied by electron microscopy. The tumor showed two types of cells, luminal and basal cells. The cells lacked the characteristics of the secretory segment of the sweat glands. The features of the luminal cells are similar to those of the intradermal portion of the eccrine sweat duct. In some areas, the lesion showed features characteristic of apocrine gland structure. Nuclear bodies were very frequent. The ultrastructural findings of eccrine cystadenoma support an origin from the ductal portion of eccrine sweat glands.