title: PIM-1 kinase expression in adipocytic neoplasms: diagnostic and biological implications.
abstract: The differential diagnosis of soft tissue tumours poses a considerable challenge for pathologists, especially adipocytic tumours, as these may show considerable overlap in clinical presentation and morphological features with many other mesenchymal neoplasms. Hence, a specific and reliable marker that identifies adipocytic differentiation is much sought. We investigated the immunohistochemical expression of PIM-1 kinase in 35 samples of soft tissue tumours using tissue microarray technology and 49 full sections of adipocytic (n = 26) and non-adipocytic tumours (n = 23). Benign and malignant adipocytic tumours showed strong expression of PIM-1 while the non-adipocytic tumours were either negative or showed only weak staining for the protein. In myxoid liposarcomas, PIM-1 showed a distinct, unique vacuolar staining pattern, clearly outlining fine cytoplasmic lipid vacuoles. By contrast, non-adipocytic myxoid tumours (myxoma, chordoma and myxoid chondrosarcoma) did not show this vacuolar pattern of PIM-1 staining, although vacuolated cells were present on H&E. This differential expression was confirmed at a gene expression level in selected cases. Our results indicate that the expression of PIM-1 in adipose tissue may be a useful marker of adipocytic differentiation, in particular if the staining is both of high intensity and present in a unique, vacuolar pattern.
authors.affiliation: Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Min En
authors.initials: ME
authors.lastname: Nga
authors.forename: Nu Nu Ma
authors.initials: NN
authors.lastname: Swe
authors.forename: Kang Ting
authors.initials: KT
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Shen
authors.forename: Michael B
authors.initials: MB
authors.lastname: Lilly
authors.forename: Siew Pang
authors.initials: SP
authors.lastname: Chan
authors.forename: Manuel
authors.initials: M
authors.lastname: Salto-Tellez
authors.forename: Kakoli
authors.initials: K
authors.lastname: Das
mesh_terms: D017667:Adipocytes / Q000201:enzymology* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D018205:Neoplasms, Adipose Tissue / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D051573:Proto-Oncogene Proteins c-pim-1 / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012509:Sarcoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D046888:Tissue Array Analysis; D014617:Vacuoles / Q000201:enzymology
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; C496634:PIM1 protein, human; D051573:Proto-Oncogene Proteins c-pim-1