ABSTRACT
A 58-year-old man was admitted to our hospital complaining of right chest pain. Chest X-ray and chest computed tomography (CT) disclosed a 9 cm mass in the right anterior mediastinum. The tumor demonstrated low signal intensity on T1-weighted images, and high signal intensity on T2-weighted images. It showed delayed enhancement on dynamic magnetic resonance (MR). The operation was performed and the tumor including the infiltrated pericardium and upper and middle lobe of right lung was resected. Histologically, the tumor showed a multinodular proliferation of spindle-shaped or polygonal tumor cells with abundant myxoid background. The histopathological diagnosis of the tumor was myxoid malignant fibrous histiocytoma (MFH). This is a case report of primary myxoid MFH in the anterior mediastinum. The case is rare in its primary site, but it is typical in CT and MR findings.
Subject(s)
Histiocytoma, Malignant Fibrous/pathology , Mediastinal Neoplasms/pathology , Humans , Male , Middle AgedABSTRACT
Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. The present study was undertaken to investigate whether treatment with the antifibrotic drug pirfenidone attenuates the bleomycin (BL)-induced overexpression of HSP47 in the lungs. Male ICR mice were intravenously injected with BL or saline (SA). Pirfenidone or control drug (CD) was administered 14 days after commencement of BL or SA, and continued throughout the course of the experiment. The mice were randomly divided into three experimental groups: 1) SA-treated with CD (SA group); 2) BL-treated with CD (BL group); and 3) BL-treated with pirfenidone (pirfenidone group). Lungs of the pirfenidone group showed a marked reduction of fibrotic lesions compared with the corresponding BL group. Immunohistochemical studies showed that BL treatment significantly increased the number of macrophages, myofibroblasts, HSP47-positive type II pneumocytes and HSP47-positive interstitial spindle-shaped cells. Treatment with pirfenidone significantly reduced the number of these cells compared with the corresponding BL group. Furthermore, treatment with pirfenidone significantly suppressed the BL-induced increase of the positive ratio of HSP47 and alpha-smooth muscle actin to interstitial spindle-shaped cells. The present study results showed that pirfenidone inhibited heat shock protein 47-positive cells and myofibroblasts, the principal cells responsible for the accumulation and deposition of extracellular matrix seen in pulmonary fibrosis.
