Decreased CD44 expression and stromal hyaluronate accumulation in myxoid dermatofibroma

Background: Dermatofibroma (DF) is a common benign histiocytic tumor, which has several clinicopathological variants. Myxoid DF is one of these variants, which is characterized by a stromal mucin deposition. CD44 is a polymorphic transmembrane glycoprotein and the principal cell surface receptor of hyaluronate (HA), the major component of the extracellular matrix. In a recent study, we have observed an abnormal accumulation of HA in the superficial dermis of transgenic mice with a keratinocyte-specific CD44 expression defect. We have also shown that HA was accumulated in large amounts in the superficial dermis of lichen sclerosus et atrophicus (LSA) lesions and that the epidermal CD44 expression of LSA skin was significantly decreased or lost. In an another study, we have suggested that a decrease in CD44 expression in follicular epithelial proliferations might be correlated with an abnormal HA accumulation in perifollicular solitary cutaneous myxoma. Recently we have also demonstrated that classical DF lesions displayed a strong CD44 expression in tumor cells and a weak HA positivity in tumor stroma whereas CD44 expression was significantly reduced or absent in dermatofibrosarcoma lesions and the tumor stroma showed strong HA staining. Objective and Methods: Here we present 3 cases of myxoid DF, in which we explored the nature of the mucinous material in myxoid stroma by colloidal iron and hyaluronic acid binding protein stainings, as well as the expression of CD44 in the tumor cells by immunohistochemistry. Results: We show that HA is accumulated in the stroma of all myxoid DF lesions with a significant decrease in CD44 expression in the tumor cells. Conclusion: Our results suggest that a decrease in CD44 expression in the tumor cells may result in stromal myxoid changes characterized by an abnormal HA accumulation in myxoid DF. Copyright (C) 2003 S. Karger AG, Basel

Primary atrophic solitary morphea profunda

Solitary morphea profunda (SMP) is a distinct form of localized scleroderma, a cutaneous disorder of unknown origin. Here, we describe a patient presenting with noninflammatory cupuliform depressed plaques, without any significant skin induration, pigmentation or texture change, that appeared on the left shoulder at a site of previous intramuscular vaccination. Light microscopy studies revealed excessive dermal collagen deposition with thickened hyalinized collagen bundles. Magnetic resonance imaging studies demonstrated tissue fibrosis with thinning of the subcutaneous fat tissue and involvement of the adjacent deltoid muscle, which was confirmed by electromyographic tests. Borrelia serology was negative. Our observation of SMP differed from previously described cases, since it mimicked localized lipoatrophy. Our observation highlights the wide spectrum of clinical presentations of localized scleroderma. The latter should be considered in the presence of lipoatrophy-like lesions for proper workup and therapy

African tick bite fever: not a spotless rickettsiosis!

African tick bite fever is caused by Rickettsia africae, a newly recognized species from South Africa. We report the case of a patient with an unusual site of a tick bite and discuss cutaneous differences from other spotted fevers that may help dermatologists with clinical diagnosis

Evaluation of the precision of operative augmented reality compared to standard neuronavigation using a 3D-printed skull

Augmented reality (AR) in cranial surgery allows direct projection of preregistered overlaid images in real time on the microscope surgical field. In this study, the authors aimed to compare the precision of AR-assisted navigation and standard pointer-based neuronavigation (NV) by using a 3D-printed skull in surgical conditions

Giant cell lichenoid dermatitis in a patient with baboon syndrome

Giant cell lichenoid dermatitis is a recently described pathological entity, which can be seen as an unusual lichenoid drug eruption, a manifestation of sarcoidosis or within herpes zoster scars. Histopathological findings include focal vacuolar alteration of the basal layer with cytoid bodies, dermal and intraepidermal multinucleated giant cells and a mixed chronic inflammatory infiltrate with a lichenoid pattern consisting of lymphocytes, histiocytes, eosinophils and plasma cells. Here, we report a giant cell lichenoid dermatitis in a 41-year-old male patient who developed, 3 days after intravenous treatment with amoxicillin-clavulanic acid for erysipelas of the left leg, a clinical picture suggesting a baboon syndrome characterized by an erythematous and pruritic eruption on the axillary, inguinal and popliteal areas and the anterior side of elbows. This is the first reported case of giant cell lichenoid dermatitis in a patient with baboon syndrome

Evaluation of the effect of standard neuronavigation and augmented reality on the integrity of the perifocal structures during a neurosurgical approach

Intracranial minimally invasive procedures imply working in a restricted surgical corridor surrounded by critical structures, such as vessels and cranial nerves. Any damage to them may affect patient outcome. Neuronavigation systems may reduce the risk of such complications. In this study, the authors sought to compare standard neuronavigation (NV) and augmented reality (AR)-guided navigation with respect to the integrity of the perifocal structures during a neurosurgical approach using a novel model imitating intracranial vessels