Rare TTF-1 positive tumors of the sellar region: Barrow Neurological Institute retrospective case series
Granular cell tumors (GCT), pituicytomas (PCT), and spindle cell oncocytomas (SCO) are relatively rare, non-functioning intrinsic pituitary tumors arising in the sellar and suprasellar regions, all recently recognized to share positive staining of thyroid transcription factor-1 (TTF-1). There are limited reports of these tumors to date, and no single institutional report with long-term follow up of all three tumor types.
Our institutional pathology database was queried for the above pathologic diagnoses. Of 16 query results, 11 patients consisting of 4 GCT, 4 PCT, and 3 SCO had complete clinical records for retrospective case series review. Clinical records were assessed for clinical presentation, pre- and post-operative endocrine status, location on imaging, surgical characteristics, pathology results, and tumor recurrence.
Although commonly reported to be predominantly female, we found no statistical difference in sex. Presentations were commonly headache (55%), fatigue (46%), vision changes (64%), and endocrine abnormalities (55%). Granular cell tumors were the only subtype to present exclusively in the infundibulum, as well as undergo a Sylvian approach to resection (n = 2) in our series. There was no significant difference between tumor types or surgical approach in terms of post-operative vision changes; SCOs were more likely to have pre-operative endocrine complications, but less likely to have post-operative worsening of endocrine status (p = 0.056). Contrary to what is commonly reported, none of the tumors were found to bleed excessively intraoperatively. All tumors were positive for TTF-1 staining. Imaging confirmed gross total resection in all 11 cases with no known recurrences at an average follow up of 4.72 ± 3.65 years.
We present our institutional series of 4 GCT, 4 PCT, and 3 SCO tumor patients, the largest to date of these three TTF-1 staining tumors of the sellar region. GCTs were reliably found to be exclusively suprasellar at presentation. SCOs tended to present with more endocrine abnormalities, but less likely to have endocrine worsening postoperatively. Gross total resection was achieved in all cases with no known recurrence at nearly 5 years of mean follow up.