PMC3764969_01
HE-stained sections of the tumor demonstrate an epithelial tumor with papillary features (left; HE x400). The tumor is strongly positive for keratin immunostaining (right; Cam5.2 x600).
cro-0006-0434-g01.jpg
PMC3764969_01_cro-0006-0434-g01.jpg
F1
The pathology was reviewed at Johns Hopkins University and has subsequently been reviewed by us; the diagnosis has been confirmed to be PTPR (fig. 1).
MRI of the tumor 2 months before (a, b) and then again immediately before (c, d) bevacizumab treatment. a Magnetic resonance (MR) axial T2 image of the posterior fossa shows a large heterogeneous mass (white arrow) in the posterior cerebellum with surrounding hyperintense signal likely related to vasogenic edema and treatment effects. b Post-contrast T1-weighted image with fat saturation shows heterogeneous enhancement of the mass (white arrow) related to the patient's known metastatic disease from his PTPR. c MR axial FLAIR image of the posterior fossa shows an increase in the size of the heterogeneous mass (white arrow) in the posterior cerebellum with surrounding hyperintense signal likely related to vasogenic edema and treatment effects. d Post-contrast T1-weighted image with fat saturation shows an increase in heterogeneous enhancement of the mass (white arrow) related to the patient's known metastatic disease from his PTPR. The mass measured 4.6 cm. A linear focus of enhancement along the left fourth ventricle is related to the patient's metastatic disease.
cro-0006-0434-g02.jpg
PMC3764969_01_cro-0006-0434-g02.jpg
F2
His MRI then showed stable 1-cm lesions in the occipital lobe but an enlarging 4.6 x 3.2 x 2.8-cm mass in the midline posterior cerebellum and a 1.7 x 1 x 2.8-cm mass abutting the fourth ventricle, both with surrounding edema and mass effect, and he was referred to the University of Utah (fig. 2).
MRI of the tumor after bevacizumab treatment. a Magnetic resonance axial FLAIR image of the posterior fossa shows a decrease in the size of the heterogeneous mass (white arrow) in the posterior cerebellum with a decrease in the associated edema after bevacizumab. The extraventricular drain is partially visualized (black arrow). b Post-contrast T1-weighted image with fat saturation shows a decrease in the heterogeneously enhancing mass (white arrow) after bevacizumab. The mass measured 2 cm and was stable for 13 months. The extraventricular drain is partially visualized (black arrow).
cro-0006-0434-g03.jpg
PMC3764969_01_cro-0006-0434-g03.jpg
F3
The FLAIR signal remained decreased as well (fig. 3).
MRI of the tumor after 13 months of bevacizumab treatment. a Magnetic resonance axial FLAIR image of the posterior fossa shows an increase in the size of the heterogeneous mass (white arrow) in the posterior cerebellum with an increase in the associated edema. The extraventricular drain is partially visualized (black arrow). b Post-contrast T1-weighted image with fat saturation shows an increase in the heterogeneously enhancing mass (white arrow) after bevacizumab. The extraventricular drain is partially visualized (black arrow).
cro-0006-0434-g04.jpg
PMC3764969_01_cro-0006-0434-g04.jpg
F4
After 13 months, both masses increased in size to 3.1 x 1.9 cm (120%) and 2.2 x 1.1 cm (84%) in cross-sectional area, respectively (fig. 4).
MRI of the tumor after 5 months of bevacizumab and etoposide treatment. a Magnetic resonance axial FLAIR image of the posterior fossa shows stability in the size of the heterogeneous mass (white arrow) in the posterior cerebellum. The extraventricular drain is partially visualized (black arrow). b Post-contrast T1-weighted image with fat saturation shows stability in the heterogeneously enhancing mass (white arrow). The extraventricular drain is partially visualized (black arrow).
cro-0006-0434-g05.jpg
PMC3764969_01_cro-0006-0434-g05.jpg
F5
Oral etoposide 50 mg/m2 for 21 out of 28 days was added, and his mass remained stable on MRI at 2, 5 (fig. 5: white arrow indicates tumor; black arrow indicates shunt), and 7 months.