7. The left second rib demonstrated an increased hyper LBH589 solubility dmso metabolic activity of SUV of 14. The patient underwent a VATS lung biopsy with wedge resection of the nodule in the right lower lobe. The wedge resection contained multiple firm white nodules. One nodule measured 1 × 0.6 × 0.5 cm,

a second nodule measured 0.6 × 0.3 × 0.2 cm and additional smaller nodules measured up to 0.2 cm in diameter. Microscopic examination revealed multiple nodular areas of eosinophilic material containing cells with small uniform nuclei. Some of these cells had prominent intra-cytoplasmic vacuoles. These cells stained positive with immunohistochemical markers for endothelial cells, CD31 and CD34, supporting the diagnosis of Epithelioid Hemangioendothelioma (EHE) (Fig. 1, Fig. 2, Fig. 3 and Fig. 4). EHE is a rare vascular tumor of intermediate behavior that was first described by Weiss in 1982 as an Intravascular Broncho-Alveolar Tumor (IVBAT).17 Pulmonary Epithelioid Hemangioendothelioma (PEH) is a rare, low grade tumor of endothelial origin17 and 6 buy Everolimus and can be found in many organ systems including the lungs, liver, bone, soft tissue and can be found sequentially, or simultaneously.5 When this occurs it can be hard to determine of the tumor is multicentric or a primary

tumor with metastases to other tissues.5 PEH is initially recognized on a chest radiograph or CT scan with the presence of unilateral or bilateral nodules which range in size up to 2 cm3 and 10 and are usually found near medium sized vessels. The problem with this radiological presentation is that it is non-specific. Many physicians would consider a PET scan an important tool used to rule out malignant lung diseases; However, in our patient, only one nodule showed FDG uptake and a negative PET scan in PEH patients is not unheard of.4 There are two Reverse transcriptase possible explanations that attempt to relate the malignancy of a nodule to the FDG uptake. The first is that a larger nodule may show a higher FDG uptake, but the PET scan can fail to detect nodules smaller than 6 mm in diameter. Secondly, a greater FDG uptake can represent a more

clinically malignant potential and the lack of tracer uptake can be evidence of a more benign character. The diagnosis of PEH is made on the basis of histopathological features which are confirmed using immunohistochemical staining. CD34, CD31 and Factor VIII are the well-recognized endothelial cell markers although a new marker, Nuclear Fli-1, a protein that is expressed in endothelial cells as well as in T-cells and megakaryocytes, is being considered for use as a marker for PEH. Gill et al. found that Nuclear Fli-1 was detected in 100 percent of their EHE cases and found that FLI-1, CD34 and CD31 were the markers most sensitive for EHE. It was also found that FLI-1 immuno-staining demonstrated better sensitivity than CD34 and better specificity than CD31.