Page 272 - Atlas of Small Animal CT and MRI

262 Atlas of Small Animal CT and MRI

Figure 2.9.19 Granular Cell Tumor (Canine) MR

(a) T1, SP (b) T1, TP (c) T2, TP

(d) T1+C, SP (e) T1+C, TP
11y M Fox Terrier a 2‐week history of seizures. Images b, c, and e are representative transverse images at the level of the pituitary fossa.
Images a and d are comparable images oriented in the sagittal plane. A large, plaque‐like, sessile mass is distributed along the floor of
the calvarium and extends into the pituitary fossa, the hypothalamus, and the right piriform lobe (d,e: arrows). The mass is mildly T1
hyperintense and T2 isointense to deep gray matter (a–c: arrows) and is uniformly and intensely contrast enhancing (d,e). Perilesional
edema is also evident (b,c: arrowhead). Although the mass involves the pituitary fossa and the pituitary gland is not evident, the constel-
lation of imaging features of this lesion is more consistent with a nonpituitary extraaxial neoplasm. The lesion was confirmed to be a
granular cell tumor on postmortem examination.

References 5. Tyson R, Graham JP, Bermingham E, Randall S, Berry CR.
Dynamic computed tomography of the normal feline hypophysis
1. Hullinger RL. The Endocrine System. In: Evans HE (ed): Miller’s cerebri (Glandula pituitaria). Vet Radiol Ultrasound. 2005;46:
Anatomy of the Dog. Philadelphia: W. B. Saunders Company, 33–38.
1993. 6. Wallack ST, Wisner ER, Feldman EC. Mensuration of the pituitary
2. Kucharczyk J, Kucharczyk W, Berry I, de Groot J, Kelly W, Norman gland from magnetic resonance images in 17 cats. Vet Radiol
D, et al. Histochemical characterization and functional signifi­ Ultrasound. 2003;44:278–282.
cance of the hyperintense signal on MR images of the posterior 7. Graham JP, Roberts GD, Newell SM. Dynamic magnetic resonance
pituitary. AJR Am J Roentgenol. 1989;152:153–157. imaging of the normal canine pituitary gland. Vet Radiol
3. van der Vlugt‐Meijer RH, Meij BP, Voorhout G. Intraobserver and Ultrasound. 2000;41:35–40.
interobserver agreement, reproducibility, and accuracy of com­ 8. Love NE, Fisher P, Hudson L. The computed tomographic
puted tomographic measurements of pituitary gland dimensions enhancement pattern of the normal canine pituitary gland. Vet
in healthy dogs. Am J Vet Res. 2006;67:1750–1755. Radiol Ultrasound. 2000;41:507–510.
4. Kippenes H, Gavin PR, Kraft SL, Sande RD, Tucker RL. Mensuration 9. Van der Vlugt‐Meijer RH, Meij BP, Voorhout G. Dynamic helical
of the normal pituitary gland from magnetic resonance images in 96 computed tomography of the pituitary gland in healthy dogs.
dogs. Vet Radiol Ultrasound. 2001;42:130–133. Vet Radiol Ultrasound. 2007;48:118–124.

262