Clinical History
Headaches and visual field defects
Imaging Findings
Admitted for headaches. Visual field defects were noted. CT and MR imaging were performed. Proton MR spectroscopy using the spin-echo point resolved spectroscopy(PRESS)sequence with TR=1500 msec, TE=135 msec, and diffusion imaging using two diffusion sensitivity (b) values (i.e. b=0, and b=1000 sec/mm2), were performed.
Discussion
In a recent in vitro MR spectroscopy study dominant peaks at 1 to 2 ppm were found in craniopharyngiomas, and it was suggested that they were consistent with lactate or lipids with trace amounts of other metabolites. In the current patient, a very prominent peak was seen at 1.0 ppm with a wide base, ranging from 0.5 ppm to 1.5 ppm, which probably corresponded to a huge cholesterol peak, correlating with biochemical findings which revealed presence of high amounts of cholesterol in the cyst fluid. On diffusion imaging, an apparent diffusion coefficient (ADC) value of 2.37 X 10-3 mm2/sec was noted in the craniopharyngioma. This ADC value is less than that of normal CSF (mean value for CSF= 3.40 X 10-3 mm2/sec), and is higher than that of vasogenic edema, and is similar to that of microcystic encephalomalacia. These MR spectroscopy, and diffusion MR findings can be helpful in differentiating craniopharyngiomas from other suprasellar masses including pituitary adenomas, glial and meningeal neoplasms, aneurysms, epidermoid tumors, dermoids, germinomas, and others.
Differential Diagnosis List
