PMC3361903_01
Morphologic appearance of a malignant EHE, showing moderate nuclear pleomorphism (A, 200x, EHE#2) and areas of necrosis (B, 200x, EHE#2); intra-vascular growth with partial obstruction of medium-sized blood vessel, highlighted by ERG immunostaining (C,D, 100x, EHE#1), as well as small tumor emboli within hepatic sinusoids and positive for ERG endothelial marker (E,F, 200x, EHE#2).
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F2
The tumor cells showed moderate nuclear atypia, a mitotic activity of 3MF/10HPFs and focal necrosis, consistent with a diagnosis of 'malignant' EHE (Fig. 2A,B). Intra-vascular tumor growth was appreciated involving medium sized vessels with complete obstruction, as well as hepatic sinusoids and small vascular spaces away from the grossly visible tumor, within normal liver parenchyma (Fig. 2E,F).
PMC3361903_02
MRI imaging of multifocal hepatic EHE, showing (A) a subscapular 2.0 cm heterogeneous lesion in the segment 7 and (B) a 2.0 cm intra-parenchymal, more homogenous lesion also located in segment 7 (EHE#1, axial T2 fat-saturated).
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F1
In EHE#1, the transcript sequence showed the fusion of the entire WWTR1 exon 3 to the last 464 bp of exon 9 of CAMTA1 in both nodules (Fig. 4A, S1). In EHE#2, the WWTR1 exon 4 was fused to the last 262 bp CAMTA1 exon 9 (Fig. 4B, S1), in all four nodules with good quality RNA that were sequenced.
Morphologic appearance of a malignant EHE, showing moderate nuclear pleomorphism (A, 200x, EHE#2) and areas of necrosis (B, 200x, EHE#2); intra-vascular growth with partial obstruction of medium-sized blood vessel, highlighted by ERG immunostaining (C,D, 100x, EHE#1), as well as small tumor emboli within hepatic sinusoids and positive for ERG endothelial marker (E,F, 200x, EHE#2).
nihms361965f2.jpg
PMC3361903_02_nihms361965f2.jpg
F2
The tumor cells showed moderate nuclear atypia, a mitotic activity of 3MF/10HPFs and focal necrosis, consistent with a diagnosis of 'malignant' EHE (Fig. 2A,B). Intra-vascular tumor growth was appreciated involving medium sized vessels with complete obstruction, as well as hepatic sinusoids and small vascular spaces away from the grossly visible tumor, within normal liver parenchyma (Fig. 2E,F).
RT-PCR using the WWTR1 and CAMTA1 primers showed amplified products of two different sizes in the two multifocal hepatic EHE#1 and EHE#2; however the two nodules from EHE#1 as well as the four nodules from EHE#2 showed an identical size band of 645 bp and 580bp, respectively.
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F3
The RT-PCR identified an amplified product in each case, but of different sizes (Fig. 3). However, the product size was identical among the different tumors from each patient (Fig. 3).
ABI sequencing of the fusion transcripts showed (A) that the entire WWTR1 exon 3 was fused to the last 464 bp of CAMTA1 exon 9 in both nodules tested of EHE#1. In addition two missense substitutions were detected in CAMTA1 exon 9 close to the exonic breakpoint in all four nodues tested, L336P and Q338R; while in (B) EHE#2 all four nodules tested had an indentical fusion structure, of WWTR1 exon 4 fused to the last 262 bp of CAMTA1 exon 9.
nihms361965f4b.jpg
PMC3361903_02_nihms361965f4b.jpg
F4
In EHE#1, the transcript sequence showed the fusion of the entire WWTR1 exon 3 to the last 464 bp of exon 9 of CAMTA1 in both nodules (Fig. 4A, S1). In EHE#2, the WWTR1 exon 4 was fused to the last 262 bp CAMTA1 exon 9 (Fig. 4B, S1), in all four nodules with good quality RNA that were sequenced.