PIM-1 kinase expression in adipocytic neoplasms: diagnostic and biological implications.
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.
Nga
Min En
ME
Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Swe
Nu Nu Ma
NN
Chen
Kang Ting
KT
Shen
Liang
L
Lilly
Michael B
MB
Chan
Siew Pang
SP
Salto-Tellez
Manuel
M
Das
Kakoli
K
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
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; C496634:PIM1 protein, human; D051573:Proto-Oncogene Proteins c-pim-1