PMC6612390_01
Computed tomography image showing multifocal hepatic lesions with peripheral enhancement and central hypoattenuation. Blue arrows point to calcifications.
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fig1
Some of the masses showed calcifications (Figure 1).
Photomicrographs of hepatic epithelioid hemangioendothelioma. (a) This mass shows one of the low magnification morphologic patterns of this tumor; well-formed vascular channels in a sclerotic matrix with focal calcification (original magnification x 100). (b) Other areas resembled focal nodular hyperplasia with a multinodular proliferation of hepatocytes around a stellate area of fibrosis (original magnification x40). (inset) The tumor cells characterized by mild nuclear atypia and abundant cytoplasm subtly infiltrate the collagen as seen in the center of this image (original magnification x400). (c) This photomicrograph shows the second phenotype of the tumor cells. Instead of well-formed vascular channels, the tumor cells are characterized by pale eosinophilic cytoplasm and intracytoplasmic vacuoles (original magnification x400). (d) The endothelial phenotype of the tumor cells is confirmed by strong and diffuse expression ERG (original magnification x100). (e) Tumor cells are negative for CAMTA1 (original magnification x100). (f) The mimic of typical focal nodular hyperplasia extended beyond hematoxylin and eosin stained stains to a map-like expression of glutamine synthetase (original magnification x40).
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A subset of the nodules contained well-formed vascular channels and scattered cords of tumor cells embedded in an abundantly sclerotic hyalinized matrix (Figure 2(a)), while other areas of tumor were characterized by small, irregular central hyalinized scars containing small subtle foci of neoplastic cells and a mild bile ductular reaction (Figure 2(b)). Scattered intracytoplasmic vacuoles were noted in the tumor cells arranged in a linear pattern (Figure 2(c)). The surrounding liver parenchyma had a nodular architecture, reminiscent of focal nodular hyperplasia (Figure 2(b)). Immunohistochemically, the tumor cells showed an endothelial phenotype with strong expression of CD31 (clone JC70A; 1/350; Dako) and ERG (clone EPR3864; predilute; Ventana) (Figure 2(d)). The tumor nuclei were positive for TFE3 (clone MRQ-37; 1/50; Cell Marque) (Figure 3(a)), but CAMTA1 (polyclonal; 1/300; Novus Biologicals) was negative (Figure 2(e)). Glutamine synthetase (clone GS-6; 1/2000; Millipore) showed a map-like pattern of distribution in the hepatocytes surrounding small irregular areas of scar mimicking focal nodular hyperplasia (Figure 2(f)).
(a) Nuclear TFE3 expression by the neoplastic cells. (b) Dual fusion fluorescent in situ hybridization probes for YAP1- (spectrum green) TFE3 (spectrum orange) showing fusion of the two loci highlighted by blue arrows. (c) Split apart fluorescent in situ hybridization showing intact CAMTA1.
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The tumor nuclei were positive for TFE3 (clone MRQ-37; 1/50; Cell Marque) (Figure 3(a)), but CAMTA1 (polyclonal; 1/300; Novus Biologicals) was negative (Figure 2(e)). Abbott Molecular, IL) using standard techniques as previously reported by our group. Interphase FISH revealed rearrangement of the TFE3 locus in all tumor cells and YAP1-TFE3 fusion at the genomic level (Figure 3(b)). An image of intact CAMTA1 split apart FISH performed using the same method and probes to the CAMTA1 locus is also shown (Figure 3(c)).