RUNX-1 and CD44 as markers of resident stem cell derivation in undifferentiated intimal sarcoma of pulmonary artery.
OBJECTIVE
To report a rare case of undifferentiated intimal sarcoma (UIS) of the pulmonary artery in a 44-year-old woman, and to study it by electron microscopy and a novel immunohistochemical (IHC) panel that recognizes markers of endothelial and haematopoietic stemness, in order to extend current knowledge about the histogenesis of this rare neoplasm.


RESULTS
Immunohistochemical reactions for CD31, CD34, α-smooth muscle actin (α-SMA), caldesmon, calponin, actin, desmin, epithelial membrane antigen, WT1, CD117, Ki67, nestin, RUNX-1, platelet-derived growth factor, NG2, CD44, CD90 and CD105 were performed manually or automatically. Neoplastic cells were negative for CD31 and CD34, but positive for calponin, nestin, WT1, CD44, and RUNX-1. Electron microscopy was performed after osmium tetroxide fixation and staining with lead citrate and uranyl acetate. Ultrastructurally, tumour cells had slightly irregular nuclei, cisternae of rough endoplasmic reticulum, and punctate intercellular junctions.


CONCLUSIONS
We report a case of pulmonary artery UIS expressing previously unreported markers, i.e. RUNX-1, nestin, WT1, and CD44, that are commonly seen in different stages of the vascular differentiation hierarchy. These findings, together with the negativity for mature endothelial and smooth muscle markers, raise the question of whether this neoplasm may derive from a vessel wall-resident stem cell, such as the haemangioblast or an embryonic-like stem cell.
Department of Specialistic Surgery and Anaesthesiological Sciences, S. Orsola-Malpighi Hospital, Bologna University, BolognaPathology Unit, Department of Radiological and Histocytopathological Sciences, S. Orsola-Malpighi Hospital, BolognaInstitute of Pathology, Bari University, Bari, Italy.
Francesco
F
Vasuri
Leonardo
L
Resta
Silvia
S
Fittipaldi
Deborah
D
Malvi
Gianandrea
G
Pasquinelli
D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D050676:Core Binding Factor Alpha 2 Subunit / Q000378:metabolism; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D009383:Neoplasms, Vascular Tissue / Q000378:metabolism / Q000473:pathology*; D011651:Pulmonary Artery / Q000473:pathology*; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology*; D013234:Stem Cells / Q000473:pathology*; D017539:Tunica Intima / Q000473:pathology
D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D050676:Core Binding Factor Alpha 2 Subunit; D018960:Hyaluronan Receptors; C493728:RUNX1 protein, human