Research advances in microRNA in pancreatic ductal adenocarcinoma / 中国医学科学院学报

MicroRNA (miRNA), small non-coding RNA consisted of 19-24 nucleotides, are able to regulate gene expression at the post-transcriptional level. The aberrant expressions of miRNA have been found in various cancers and contribute to carcinogenesis by promoting the expression of proto-oncogenes or by inhibiting the expression of tumor suppressor genes. miRNA are related closely with the oncogenesis, progression, and prognosis of tumors. The discovery of the aberrant expression of miRNA in pancreatic ductal adenocarcinoma (PDA) and its target genes are helpful for the understanding of the pathogenesis of PDA and for the early diagnosis and prediction of this disease. In this paper, we summarize the recent research advances in miRNA expression in PDA and its target genes and discuss the potential role of miRNA in the diagnosis, and treatment of PDA.

Pathologic study of diffuse pulmonary interstitial fibrosis caused by chronic hypersensitivity pneumonitis / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the pathologic characteristics of chronic hypersensitivity pneumonitis, especially the pattern of pulmonary interstitial fibrosis; and to compare the histologic features with those of idiopathic interstitial pneumonitis.</p><p><b>METHODS</b>The HE-stained paraffin sections of 10 cases of chronic hypersensitivity pneumonitis encountered during the period from 2000 to 2008 were retrospectively analyzed.</p><p><b>RESULTS</b>There were altogether 6 males and 4 females, with age of patients ranging from 23 to 59 years (mean=47.2 years). Clinically, the patients presented with chronic cough and shortness of breath for 4 months to 6 years. Histologically, 7 cases showed usual interstitial pneumonitis (UIP)-like fibrosis. Patchy fibrosis was observed under the pleura, adjacent to interlobular septa and around bronchioles. In all of the 7 cases, foci of fibroblastic proliferation, as well as bronchiolar metaplasia of peribronchiolar alveoli and mild bronchiolitis, were noted. Three cases presented with mild honeycomb changes of lung and 3 cases showed non-specific interstitial pneumonitis (NSIP)-like fibrosis, in which the alveolar septa were expanded by fibrous tissue and collagen, with relative preservation of alveolar architecture. Bronchiolitis and lymphocytic infiltrates in alveolar septa were seen. Schaumann bodies were identified in 1 case. In general, patients with chronic hypersensitivity pneumonitis were younger than patients with idiopathic UIP. Computed tomography often showed upper and middle lobar involvement and mosaic attenuation. Compared with idiopathic UIP, the UIP-like fibrosis of chronic hypersensitivity pneumonitis often occurred not only under the pleura and adjacent to interlobular septa, but also around bronchioles and was accompanied by bronchiolar metaplasia.</p><p><b>CONCLUSIONS</b>Chronic hypersensitivity pneumonitis can mimic other types of lung conditions with interstitial fibrosis, especially UIP and NSIP. As a result, some cases of chronic hypersensitivity pneumonitis may be misdiagnosed as such.</p>

Extranodal Rosai-Dorfman disease / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the diagnosis and differential diagnosis of extranodal Rosai-Dorfman disease.</p><p><b>METHODS</b>Two cases of extranodal Rosai-Dorfman disease were studied using hematoxylin-eosin, and immunohistochemical staining, along with a literature review.</p><p><b>RESULTS</b>The lesions of RDD were characterized by the presence of large histiocytes with emperipolesis, accompanied by infiltration of lymphocytes, plasma cells and other inflammatory cells. The large histiocytes had an abundant cytoplasm, pale to eosinophilic in appearance, positive for S-100 protein staining, with a vesicular nucleus and a small basophilic nucleolus in each cell.</p><p><b>CONCLUSIONS</b>Extranodal Rosai-Dorfman disease is known as an idiopathic proliferative disease of histiocytes with a distinct morphologic feature and is very rare. Differential diagnosis from other types of fibrohistiocytic proliferation lesions is recommended.</p>