Transcript Case Study - University of Pittsburgh

Case Study 44
Julia Kofler, M.D.
Question 1
Clinical history:
36 year old female with a 5 year history of
panhypopituitarism and increasing visual deficits.
Describe the lesion on the following MRI scan.
Question 1
T1
T1 with contrast
T1 with contrast
Answer
Diffusely contrast-enhancing suprasellar mass
Question 2
What is your differential diagnosis based on the radiologic
appearance and location of the lesion?
Answer
 Pituitary adenoma
 Craniopharyngioma
 Pituicytoma
 Granular cell tumor
 Meningioma
 Pilocytic astrocytoma
 Germ cell tumor
Question 3
An endoscopic endonasal resection was performed. An
intraoperative consultation was requested. What is your
interpretation of the following touch prep?
According to the surgeon, the mass appears to be arising
from the infundibulum.
Click here to view slide.
Answer
 Hypocellular touch prep consisting predominantly of
blood
 No evidence of pituitary adenoma
 Rare large polygonal cells with abundant granular
cytoplasm (macrophages vs granular cells)
 Overall, a granular cell tumor is favored
Question 4
Describe the findings on the permanent section.
Click here to view slide.
Answer
Moderately cellular neoplasm composed of elongated to
large polygonal cells with abundant coarsely granular
cytoplasm and eccentric nuclei with inconspicuous
nucleoli.
Question 5
Which stains may be ordered to further work up this
case?
Answer
 PAS w/wo diastase
 S100
 GFAP
Question 6
What is your interpretation of the following stains?
Click here to view PAS-D slide.
Click here to view S100 slide (red chromogen).
Click here to view GFAP slide (brown chromogen).
Answer
 PAS-D strongly stains the cytoplasmic granules
 S100 is patchy weakly to moderately positive
 GFAP is negative in the tumor cells; highlights rare
glial processes at the edge of the tumor
Question 7
Is this the expected staining pattern for infundibular
granular cell tumors?
Answer
Yes
 PAS and PAS-D strongly stain the cytoplasmic
lysosomal granules
 S100 is usually positive, but may be variable
 GFAP is usually negative
Question 8
What is your final diagnosis in this case?
Answer
Granular cell tumor
Question 9
What is the presumed cell of origin of granular cell
tumors?
Answer
Pituicytes
Question 10
Name a lesion that is related to infundibular granular cell
tumors and can be seen incidentally in ~10% of autopsy
pituitaries?
Answer
Granular cell tumorlet/tumorette/choristoma is a
microscopic granular cell proliferation in the infundibulum
or neurohypophysis and histologically similar to the larger
granular cell tumor