A great number of lichenoid lesions have overlapping clinicopathological features, so the use of adjunct tests to establish definitive diagnosis is recommended for correct management and prognosis of the lesions. In this context, direct immunofluorescence (DIF) can be a useful tool. Thus, this study aimed to characterize the clinical, histopathological, and DIF pattern in patients with oral lichen planus (OLP) and patients with oral lichenoid lesions (OLLs). Patients with OLP and patients with OLL were characterized and compared with patients with mucous membrane pemphigoid, pemphigus vulgaris, and fibrous hyperplasia through a cross-sectional study. Patients with OLP (n = 30) and patients with OLL (n = 26) were mostly white women in the fifth decade of age, with reticular lesions mainly on the buccal mucosa. All patients with OLP and half of the patients with OLL showed liquefaction degeneration at the basal cell layer and a band-like lymphocytic infiltrate in the subepithelial tissue. Twenty-two patients with OLP (73.3%), 10 with OLL (38.4%), 25 with mucous membrane pemphigoid (96.1%), and all with pemphigus vulgaris (100%) had positive DIF. There was no positive DIF in patients with fibrous hyperplasia. The most frequent DIF pattern in patients with OLP and patients with OLL was linear fibrinogen at the basement membrane zone, and a logistic regression model for positive DIF found statistically significant difference in OLP versus OLL (odds ratio, 3.73; confidence interval, 1.23-11.38). Although clinical and histopathological features are sufficient for diagnosing most of the patients with OLP and OLL, DIF is a key tool in differentiating some lichenoid lesions and could improve the diagnosis of OLP and OLL, especially in lesions showing typical clinical and histological features of OLP.

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BackgroundParaneoplastic pemphigus is a rare multiorgan disease of autoimmune causes, usually triggered by neoplasias, mainly of lymphoproliferative origin, such as leukemia and lymphoma. This disorder is categorized by the presence of autoantibodies that react against proteins, such as desmoplakins, desmogleins, desmocollins, and others that exist in cellular junctions. Paraneoplastic pemphigus can manifest clinically in a variety of ways, ranging from mucositis to lesions involving the skin and pulmonary changes. The diagnosis depends on the correlation between the clinical and histopathologic evaluations. Currently, the treatment of this disease is still very difficult and ineffective. The prognosis is poor, and the mortality rate is very high.Case presentationWe report a case of a Caucasian patient who had chronic lymphocytic leukemia and developed paraneoplastic pemphigus with severe impairment of skin and mucosa. The initial diagnostic hypothesis was Stevens-Johnson syndrome. The histopathological examination of the skin biopsy was compatible with paraneoplastic pemphigus, and the definitive diagnosis was made on the basis of clinical-pathological correlation.ConclusionsWith the presence of multiorgan lesions in patients with lymphoproliferative neoplasia, paraneoplastic pemphigus should always be considered among the possible diagnostic hypotheses, because diagnosis and early treatment may allow a better prognosis for the patient.

Objective: To evaluate intra-and interobserver agreement in the identification of incidental enchondromas at knee magnetic resonance imaging, and to assess the prevalence of imaging findings. Materials and Methods: Retrospective study reviewing 326 knee magnetic resonance images acquired in the period between November 2009 and September 2010. The images were independently and blindly analyzed by two specialists in musculoskeletal radiology, with the objective of identifying incidental enchondromas, presence of foci with signal similar to bone marrow and foci of signal absence suggestive of calcifications within the enchondromas. Inter-and intraobserver agreements were analyzed. Results: Eleven lesions compatible with enchondromas (3.3%) were identified. The interobserver agreement for the presence of enchondroma was high. Prevalence of foci of bone marrow signal inside the enchondromas was of 54.55%, and foci suggestive of calcification corresponded to 36.36%. The intraobserver agreement for foci of bone marrow signal in enchondromas was perfect, and interobserver agreement was high. Conclusion: The prevalence of incidental enchondromas in the current study was compatible with data in the literature. Excellent agreement was observed in the identification of enchondromas and in the assessment of imaging findings. A higher prevalence of fat signal foci was observed as compared with signal absence suggestive of calcifications. Keywords: Enchondromas; Magnetic resonance imaging; Knee; Bone marrow.Objetivo: Avaliar a confiabilidade intra e interobservador na identificação de encondromas incidentais na ressonância magnética de joelho e estudar a prevalência das características de imagens destas lesões. Materiais e Métodos: Estudo retrospectivo, com revisão de 326 ressonâncias magnéticas do joelho realizadas entre novembro de 2009 e setembro de 2010. As imagens foram analisadas por dois médicos especialistas em radiologia musculoesquelética, de forma independente e às cegas, visando a identificar encondromas incidentais, presença de focos com sinal semelhante à medula óssea e focos de ausência de sinal sugestivos de calcificações no interior dos encondromas. Foram realizadas análises das concordâncias inter e intraobservador. Resultados: Foram identificadas 11 lesões compatíveis com encondromas (3,3%). A concordância interobservador para presença de encondroma foi alta. A prevalência de focos de sinal de medula óssea no interior dos encondromas foi 54,55% e de focos sugestivos de calcificação foi 36,36%. A concordância intraobservador para focos de sinal de medula óssea nos encondromas foi perfeita, e a concordância interobservador foi alta. Conclusão: A prevalência de encondromas incidentais no trabalho atual foi consistente com a literatura. Foi observada excelente concordância no estudo de confiabilidade da identificação de encondromas e de suas características, notando-se maior prevalência de focos com sinal de gordura do que de calcificações. Unitermos: Encondromas; Ressonância magnética; Joelho; Medula óssea. Ab...

Malignant triton tumor (MTT) is an aggressive peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Less than 100 cases have been described, being mostly male children with type 1 neurofibromatosis. We report a 6-year-old female with MTT and no diagnostic criteria for neurofibromatosis type 1. Cytogenetic analysis showed a 46,X,-X[4]/46,XX[16] karyotype. She underwent a transfemoral amputation and chemotherapy and is free of disease 15 months after diagnosis. The few cytogenetic studies of MTT described in the literature have been inconclusive. Further cytogenetic analyses are needed to understand the role of chromosome X monosomy in the pathogenesis of this rare tumor.