Clinical Pathologic And Immunohistochemical Studies Of Inflammatory Pseudotumor

Objective 1 To analyze the clinicopathological features of inflammatory pseudotumor, inflammatory myofibroblastic tumor and organizing pneumonia. 2 To identify the expression and clinical value of ALK, SMA and P53 protein in inflammatory pseudotumor and organizing pneumonia. Methods 100 cases of inflammatory pseudotumor(42 cases of fibrohistiocytic type, 58 cases of plasma cell granuloma type) of the lung and 10 cases of organizing pneumonia were chosen from the patients who were diagnosed inflammatory pseudotumor in department of Pathology, Cancer Institute & Hospital Affiliating Tianjin Medical University during the period of February 1999 to Aprial 2005. Archival tissue specimen of these 110 cases were examined for ALK, SMA and P53 expression by way of immunohistochemical staining. Rusults 1 Clinical manifestationIn the one hundred patients who had IPT , 79 patients were male;5 patients who had organizing pneumonia were male. The ages of the 100 patients who had IPT were between 38 and 73, the number of patients who were lower than 50, higher than 60, between 50 and 59 were 37, 25, 38 cases respectively. 58 cases of IPT were located in the right lung;4 cases of organizing pneumonia were located in the right lung.The diameter ofIPT was between 1. 2cm and 15cm, and the diameter of organizing pneumonia was between lcm and 7cm. The common symptoms were cough, expectoration, bloody phlegm, chest distress, chest pain, fever etc. In our patients 5 cases of FHC ,4 PCG and 1 organizing pneumonia had no symptom.2 Pathologic findingsMacrogrophy: There were no obvious differentiation among FHC , PCG and organizing pneumonia.Microgrophy: FHC was mainly composed of spindle cells including myofibroblast admixed with a prominent inflammatory infiltrate usually consisting of lymphocytes and plasma cells, focal ossification and calsification also could be seen. PCG was mainly composed of spindle cells including myofibroblast, fibroblast and collagen fiber with a great quantity of plasmacyte infiltration, Russell corpuscle and lymphocyte also could be seen;sometimes we could see lymphatic follicle in the edge of the lesion. In organizing pneumonia , fibroblast proliferated and entered into bronchiole, alveolar duct and fiberous lock or fibrous polyp. Suppuration and Masson corpuscle also could beseen.3 Immunohistochemical phenotype3.1 The expression of ALK proteinThe rate of immuno-positive staining of ALK protein in inflammatory pseudotumor of the lung was 30%, in which the rates in fibrohistiocytic type and plasma cell granuloma type were 52. 4%, 13. 8% respectively, There was obvious difference between them. There was no relationships betweenthe rate of immuno-positive staining of ALK protein and sex, site, tumor size and symptom(P>0. 05) in inflammatory pseudotumor of the lung;the expression status of ALK in patients older than 53 was higher than those younger than 53 years old. In the inflammatory pseudotumor of the lung, there was one case in cases of immuno-positive staining of ALK protein had lymph node metastasis (3. 3%), and two cases in cases of immuno-negetive staining of ALK protein had lymph node metastasis(1. 4%). All the 10 cases organizing pneumonia were immuno-negative staining of ALK protein. 3.2 The expression of SMA protein and its relationship with ALK proteinThe rate of immuno-positive staining of SMA protein of the lung was 86%, no significant difference was found between fibrohistiocytic type, and organizing pneumonia. There was obvious relationships between the expression of SMA and ALK (P<0.01) in inflammatory pseudotumor. 3. 3 The expression of P53 proteinNo one of the cases of inflammatory pseudotumor and organizing pneumonia were positive expression of P53 protein. Conclusion 1 The expression status of ALK protein in was higher than in significantly, inflammatory pseudotumor and inflammatory myofibroblastic tumor may not be a same concept, in inflammatory pseudotumor , many of fibrohistiocytic type may be,and at least some plasma cell granuloma type may be inflammatory myofibroblastic tumor. 2 In inflammatory pseudotumor, the cases of immuno-positive staining of ALK protein often were patients from 50 to 70 years old. There were no relationships between the rate of immuno-positive staining of ALK proteinand sex, site, tumor size and symptom in inflammatory pseudotumor of the lung. 3 There was one case in three cases who had lymph node metastasis expressed ALK protein, which meant the expression of ALK protein were not related with lymph node metastasis. 4 There was obvious right relationship between the expression of SMA and ALK. 5 No one of the cases of inflammatory pseudotumor and organizing pneumonia were positive expression of P53 protein,which meant gene mutation of P53 might not be the main tumorigenesis mechanism of IMT.