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Michael Landthaler

Publications and source records attributed to Michael Landthaler.

At least 55 records · Page 3Linked to original sources
PubMed2005

Neodymium-YAG Laser for hemangiomas and vascular malformations -- long term results.

BACKGROUND: Hemangiomas and vascular malformations are the most common vascular lesions of infancy. Different lasers can be used for treatment. Nd:YAG laser photocoagulation is particularly effective because of its deep penetration into tissue. PATIENTS AND METHODS: Thirty-one patients, aged from three months to 18 years, with voluminous hemangiomas and venous malformations were treated with a cw-neodymium:YAG laser. The quartz fibre was used in percutaneous and intralesional technique. Long-term follow-up data were acquired by clinical control or a patient questionnaire for a maximal period of eight years. Twenty patients could be evaluated. RESULTS: In the group with hemangiomas (n = 15), three cases showed nearly complete remission (> 90 %), ten cases had a partial reduction in size (50 - 90 %), in one case there was stable disease and in one case tumor growth. In the group with venous malformations (n = 5) two cases showed an excellent response (> 90 %), one case a moderate response (25 - 50 %) and in two cases there was no improvement. Adverse effects included scars (40 %), hyper- and hypopigmentation (23 %), mild atrophy (20 %) and a wrinkled texture (17 %). After maximal reduction in size, 30 % of the patients were not satisfied with the laser treatment outcome and elected surgical excision of the residual lesion. CONCLUSIONS: The neodymium:yttrium aluminium garnet (Nd:YAG) laser with percutaneous or intralesional application technique is a valuable tool for selected patients with hemangiomas and venous malformations.

Adolescent↗
PubMed2005

Early recurrence of eruptive vellus hair cysts after Er:YAG laser therapy: case report and review of the literature.

BACKGROUND: Therapy of eruptive vellus hair cysts (EVHCs) often leads to unsatisfying results or recurrences. Recently, erbium:yttrium-aluminum-garnet (Er:YAG) laser therapy has been recommended in this condition. OBJECTIVE: To report the results of Er:YAG laser treatment and discuss the treatment options in EVHC, presenting a review of the literature. METHODS: Full-face Er:YAG laser therapy was performed in a 30-year-old female patient with a 15-year history of cosmetically bothersome facial EVHCs. RESULTS: Immediately after the laser treatment, the ablated skin showed an even surface, presenting no residual signs of EVHCs. After reepithelialization, however, early recurrence of EVHCs occurred. Recurrence was also observed in the previously treated test spot, where slight atrophy indicated deeper ablation. CONCLUSION: Er:YAG laser therapy might be a treatment option for distinct lesions of EVHCs but proved to be ineffective in a case of EVHCs in the face, where the depth of ablation is limited owing to the risk of atrophy or scarring and where deep enucleation of distinct single cysts was not possible owing to the dense dissemination of the lesions. Despite numerous treatment options reported in the literature, therapy for EVHCs is still challenging owing to recurrences or side effects.

Adult↗
PubMed2005

Ephrin-B2 overexpression enhances integrin-mediated ECM-attachment and migration of B16 melanoma cells.

Eph-receptor tyrosine kinases (Eph-RTKs) and their membrane-bound receptor-like ligands, the ephrins, represent a cell-cell signaling system that directs cellular migration during development. Differential expression in cancer suggests similar roles in tumor progression. We have previously shown that ephrin-B2 mRNA is overexpressed in advanced malignant melanomas (MM). In this study, immunohistochemistry revealed a most prominent expression of ephrin-B2 in the invasive front of advanced MM. Therefore, we addressed the question of whether ephrin-B2 signaling modulates MM cell migration and matrix interaction. Using a wild-type ephrin-B2-negative B16 mouse MM subclone we show that overexpression of ephrin-B2 leads to the formation of multiple lamellipodia, enhanced polymerisation of actin fibers, and induction of focal adhesion complexes with constitutive activation of focal adhesion kinase. Consequently, ephrin-B2-overexpressing B16 cells display a significant increase of beta1-integrin-mediated attachment to matrix components, preferentially laminin and fibronectin. As a further effect of ephrin-B2 overexpression, we observed an accelerated migration in both Boyden chamber invasion experiments as well as in in vitro scratch-wound assays. We conclude that ephrin-B2 can act as a major modulator of cell migration and matrix interactions of MM cells, which possibly contributes to the expansion and metastatic spread of MM in vivo.

Animals↗
PubMed2004

Differential gene expression of Eph receptors and ephrins in benign human tissues and cancers.

BACKGROUND: Eph receptors and their ligands, the ephrins, represent a large class of cell-cell communication molecules with well-defined developmental functions. Their role in healthy adult tissues and in human disease is still largely unknown, although diverse roles in carcinogenesis have been postulated. METHODS: We established a set of fluorescent PCR probes and primers for the definition of individual gene expression profiles of 12 different Eph receptors and 8 ephrins in 13 different healthy tissues. The mRNA expression profiles were studied in human lung, colorectal, kidney, liver, and brain cancers. RESULTS: The family of Eph receptors/ephrins was widely expressed in adult tissues with organ-site-specific patterns: EphB6 was highest in the thymus, compatible with an involvement in T-cell maturation. Brain and testis shared a unique pattern with EphA6, EphA8, and EphB1 being the most prominent. EphA7 had a high abundance in the kidney vasculature. Ephrin-A3 was up-regulated 26-fold in lung cancer, and EphB2 was up-regulated 9-fold in hepatocellular carcinoma. EphA8 was down-regulated in colon cancer, and EphA1/EphA8 was down-regulated in glioblastomas. CONCLUSION: Eph/Ephrin genes are widely expressed in all adult organs with certain organ-site-specific patterns. Because their function in adult tissues remains unknown, further analysis of their role in disease may disclose new insights beyond their well-defined meaning in development.

Adult↗
PubMed2004

Antiangiogenic therapy with pioglitazone, rofecoxib, and trofosfamide in a patient with endemic kaposi sarcoma.

BACKGROUND: Kaposi sarcoma (KS) in patients who are seronegative and seropositive for human immunodeficiency virus is currently the most common malignant tumor in central Africa. It accounts for 50% of all tumors reported in central African countries. Owing to the rising number of patients and the limitations of current therapies, there is an urgent demand for new strategies to treat KS. OBSERVATION: We describe a 42-year-old dark-skinned patient from Mozambique with endemic KS. The tumor was first diagnosed 8 years earlier when an ulcerated nodule appeared at his right ankle joint. Subsequently, multiple reddish brown nodules appeared on both feet and the left thigh. Results of dermatohistopathological analysis confirmed the diagnosis of KS. Topical therapies including cryotherapy, carbon-dioxide laser, and photodynamic therapy could not prevent new recurrences and further cutaneous dissemination. Therefore, a novel antiangiogenic systemic therapy was started that was previously shown to be effective in angiosarcomas other than KS. The regimen consists of the biomodulators pioglitazone hydrochloride and rofecoxib combined with a metronomic (daily) low-dose chemotherapy with trofosfamide. We observed a partial remission, which has been stable for 18 months. No significant toxic effects were observed. CONCLUSION: The suggested antiangiogenic strategy has the potential to become a cheap, practical, feasible alternative treatment for endemic KS, particularly suitable for the outpatient setting.

Adult↗
PubMed2004

Discrimination of melanocytic tumors by cDNA array hybridization of tissues prepared by laser pressure catapulting.

Gene expression profiling by cDNA array analysis in melanoma is hampered by the need for large amounts of RNA to prepare reliable probes for array hybridization. On the other hand, for ex vivo analysis of malignant cells from melanocytic tumors laser pressure catapulting is an essential prerequisite to obtain noncontaminated melanocytic preparations; however, laser pressure catapulting prepared material provides only nanogram amounts of RNA. In this study we present an approach to overcome these limitations by combining laser pressure catapulting and real-time polymerase chain reaction based SMART cDNA amplification technology. Reproducible and reliable hybridization patterns from about 500 laser pressure catapulting prepared cell equivalents from 22 cases of melanocytic tumors were generated using array analysis. Univariate analysis revealed significant differences of the expression pattern of melanocytic nevi, melanomas, and melanoma metastases. Multivariate analysis with four genes being the best univariate discriminative features (tyrosinase related protein 2, translation initiation factor 2 gamma, ubiquitine conjugating enzyme E2I and one expressed sequence tag) allowed clustering of nevi, melanomas, and melanoma metastases with an accuracy of 82%. Data validation was performed by additional quantitative reverse transcription-polymerase chain reaction (TaqMan-reverse transcription-polymerase chain reaction). Taken together, this study shows, that (1) array analysis is feasible on tumors with rather low cell numbers, and (2) differences in expression profiles allow discrimination between benign and malignant lesions. Expression patterns of marker genes defined in unequivocal histopathologic entities may improve the diagnostic and prognostic assessment of difficult melanocytic lesions, which is still the hardest problem in dermatopathology.

Biopsy↗
PubMed2004

[The "red melanoma"--a rare form of amelanotic malignant melanoma].

The two major variants of amelanotic malignant melanoma are the verrucous and the polypoid forms. A further--albeit rare--red eczematous variety has also been described. We report two female patients with reddish, non-pigmented, scaly lesions on the upper arm and the shoulder that had developed 2 to 3 years previously. One biopsy showed the diagnosis of a melanoma growing in situ while the second revealed a highly atypical melanocytic tumour. However, the histopathological examination of the entire tumour showed a superficial spreading amelanotic malignant melanoma. Therefore, in non-healing erythematous lesions, even without pigmentation or ulceration, the rare differential diagnosis of amelanotic malignant melanoma should be taken in consideration and a biopsy should be performed prior to therapy without histological control.

Aged↗
PubMed2004

Progressive hyperpigmentation and generalized lentiginosis without associated systemic symptoms: a rare hereditary pigmentation disorder in south-east Germany.

Familial progressive hyperpigmentation is rarely described in the literature. We report on five patients from three different families presenting with a peculiar progressive pigmentary disorder. The patients show a progressive diffuse, partly blotchy, hyperpigmentation, intermixed with scattered small hypopigmented macules, a few large hypopigmented areas, occasional café-au-lait spots and, most remarkably, a generalized lentiginosis. Histology revealed different degrees of basal layer hyperpigmentation and pigment incontinence, also in the spots appearing hypopigmented. Ultrastructural analysis showed a normal mode of Caucasian-like melanogenesis with varying content of regular melanosome complexes within the keratinocytes. All families are clustered in a small area around the town of Teublitz in south-east Germany with about 20,000 inhabitants, suggesting a genetic founder effect. Pedigree analysis is compatible with an autosomal dominant mode of inheritance with variable penetrance. Only a few similar, but not identical, cases have been reported in the past. This cluster of cases may therefore represent a rare and perhaps novel variant of a familial progressive disorder of hyperpigmentation.

Adolescent↗
PubMed2004

Lentigo maligna and lentigo maligna melanoma in young adults.

BACKGROUND: We observed two young women with skin types II to III according to Fitzpatrick's classification who developed pigmented macules in the face that were histologically diagnosed as lentigo maligna melanomas. OBJECTIVE: The objective of this study was to examine lentigo maligna melanoma in young adults. METHODS: According to private photographs of one of those patients a precursor lesion was clinically apparent as early as in her 26th year. Ten years later, the diagnosis of a lentigo maligna melanoma was made. The other patient was diagnosed with lentigo maligna at the age of 37. After excision, a relapse occurred in her 39th year. At this time histopathology revealed an early invasive lentigo maligna melanoma. RESULTS: These case reports demonstrate that the diagnosis of both lentigo maligna and lentigo maligna melanoma cannot be dismissed because of young age or well-tanning skin types. CONCLUSION: We conclude that owing to changes in social behavior and sporting activities with high short-term ultraviolet exposures, one must be aware of the possibility of an unusual early onset of lentigo maligna and lentigo maligna melanoma already in the third and fourth decade of life. Furthermore, our observations support the effectiveness of dermatoscopy in diagnosing ambiguous pigmented skin lesions in sun-exposed skin.

Adult↗
PubMed2003

Antiangiogenetic therapy with pioglitazone, rofecoxib, and metronomic trofosfamide in patients with advanced malignant vascular tumors.

BACKGROUND: Systemic therapy options for patients with advanced angiosarcomas are limited, and their prognosis is poor. The idea of angiostatic therapy following the paradigm of metronomic dosed chemotherapeutics combined with proapoptotic biomodulators had not been considered previously in these patients. Therefore, in a pilot study, the efficacy of metronomically scheduled, low-dose trofosfamide in combination with the peroxisome proliferator-activated receptor gamma agonist, pioglitazone, and the selective cyclooxygenase-2 inhibitor, rofecoxib, was evaluated in patients with advanced vascular malignancies. METHODS: Six patients with advanced and pretreated but progressive, malignant vascular tumors (5 angiosarcomas and 1 hemangioendothelioma) received a combination of pioglitazone (45 mg per day orally) plus rofecoxib (25 mg per day orally) and, after 14 days, trofosfamide (3 x 50 mg per day orally). The therapy was administered continuously until progression was observed. If necessary, doses were modified according to side effects. RESULTS: Two patients responded with complete remission of disease, one patient responded with partial remission, and three patients achieved stabilization of disease (no change). The median progression-free survival was 7.7 months (range, 2-15 months). Side effects generally were mild (World Health Organization Grade 1-2). Hospitalization was not necessary. CONCLUSIONS: This new triple combination of low-dose metronomic trofosfamide, pioglitazone, and rofecoxib may represent a feasible new alternative in the palliative treatment of patients with advanced malignant vascular tumors.

Administration, Oral↗
PubMed2003

Treatment of oral lichen planus with the 308-nm UVB excimer laser--early preliminary results in eight patients.

BACKGROUND AND OBJECTIVES: Oral lichen planus (OLP) is a chronic disease of uncertain origin. Many patients with OLP are refractory to all available therapies. The 308-nm excimer laser was used as a possible additional method in the treatment of OLP. STUDY DESIGN/MATERIALS AND METHODS: Eight patients with OLP were treated using the 308-nm UVB excimer laser. RESULTS: Clinical improvement was achieved in six patients. Two patients showed complete remission, of which one patient showed recurrence of the lesions after 4 weeks. CONCLUSION: The preliminary results in our opinion warrant further studies of this treatment.

Adult↗
PubMed2003

[Porokeratotic eccrine ostial and dermal duct naevus (PEODDN)].

The porokeratotic eccrine ostial and dermal duct naevus or PEODDN represents a very rare hamartoma of the eccrine sweat glands. A 16-year old boy had developed subtle hyperkeratotic skin lesions on his right hallux at six months of age. When he was eight years old, he developed similar lesions on his right palm. Clinically the lesions were coniform hyperkeratoses. The histopathological examination confirmed the diagnosis of a PEODDN showing typical cornoid lamella where the eccrine secretory ducts penetrated the epidermis. Although porokeratotic eccrine ostial and dermal duct naevi are generally considered as unresponsive to conservative treatment, in our patient topical treatment with tazarotene gel 0.1% resulted in a significant improvement within three weeks.

Administration, Topical↗
PubMed2003

Influence of 5-aminolevulinic acid and red light on collagen metabolism of human dermal fibroblasts.

Patients with localized scleroderma receiving topical photodynamic therapy with 5-aminolevulinic acid show a reduction in skin tightness, suggesting that this therapy reduces skin sclerosis. To investigate potential mechanisms, the effects of 5-aminolevulinic acid and light on collagen metabolism were studied in vitro. Normal and scleroderma fibroblasts were treated with sublethal doses of 5-aminolevulinic acid and red light and transferred to three-dimensional collagen lattices. Cell supernatants were taken 6-72 h after photodynamic therapy to determine protein levels of the matrix metalloproteinases 1, 2, and 3, and of their inhibitors, tissue inhibitor of metalloproteinase 1 and 2 by enzyme-linked immunosorbent assay. Cellular mRNA expression of these proteins and of collagen type I and III was measured by quantitative real-time polymerase chain reaction. A significant, time-dependent induction of matrix metalloproteinase 1 (up to 2.4-fold after 48 h) and matrix metalloproteinase 3 (up to 4.3-fold after 48 h) protein levels was seen after 5-aminolevulinic acid-photodynamic therapy. Irradiation with ultraviolet A light, used as a positive control, showed a similar induction of matrix metalloproteinase 1 (2.3-fold after 48 h). The mRNA levels of matrix metalloproteinase 1 and matrix metalloproteinase 3 were significantly increased 12 h after irradiation, whereas collagen type I mRNA was strongly decreased already 6 h following irradiation. Collagen type III, tissue inhibitor of metalloproteinase 1, and matrix metalloproteinase 2 did not change after photodynamic therapy. Addition of nontoxic concentrations of sodium azide, a singlet-oxygen quencher, significantly inhibited induction of matrix metalloproteinase 1 by 5-aminolevulinic acid and light. These data show that 5-aminolevulinic acid and light induce matrix metalloproteinase 1 and matrix metalloproteinase 3 expression in normal and scleroderma fibroblasts in a singlet oxygen-dependent way while reducing collagen type I mRNA expression. Induction of collagen-degrading enzymes together with reduction of collagen production might be responsible for the anti-sclerotic effects of 5-aminolevulinic acid-photodynamic therapy observed in vivo.

Aminolevulinic Acid↗
PubMed2003

Bullous malignant melanoma: an unusual differential diagnosis of a hemorrhagic friction blister.

BACKGROUND: A 66-year-old woman presented to our outpatient clinic with a 3 x 2.5-cm tense, hemorrhagic-appearing bulla on her forefoot. Histopathology and immunohistochemistry confirmed a transtumoral-transepidermal blister formation within an advanced acrolentiginous malignant melanoma (MM). OBJECTIVE: To study bullous malignant melanoma. METHODS: Blistering in MMs represents a rare but clinically important pitfall in clinical differential diagnosis. The blisters are typically due to the disruption of the cohesion between neoplastic cells and keratinocytes, but physical friction may also contribute. RESULTS: Hemorrhagic blistering is, in many cases, a relatively insignificant finding in which frictional forces are imposed. CONCLUSION: The case reported here underscores that in rare cases MMs, particularly if acrally located, can be complicated by hemorrhagic blistering. Because of the life-threatening consequences, one should be aware of this rare differential diagnosis.

Aged↗