Stalking the stalk: Isolated pituitary stalk thickening and predictive factors for proliferative disease

Julie Bennett; Liana Nobre; Eric Bouffet; Oussama Abla; Bryan Maguire; Afsaneh Amirabadi; Cynthia Hawkins; Jonathan D Wasserman; Birgit Ertl-Wagner; Ute Bartels

doi:10.1093/noajnl/vdae214

Stalking the stalk: Isolated pituitary stalk thickening and predictive factors for proliferative disease

Neurooncol Adv. 2024 Dec 14;6(1):vdae214. doi: 10.1093/noajnl/vdae214. eCollection 2024 Jan-Dec.

Authors

Julie Bennett^{1

2}, Liana Nobre³, Eric Bouffet², Oussama Abla², Bryan Maguire⁴, Afsaneh Amirabadi⁵, Cynthia Hawkins⁶, Jonathan D Wasserman⁷, Birgit Ertl-Wagner^{8

5}, Ute Bartels²

Affiliations

¹ Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
² Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, Ontario, Canada.
³ Division of Hematology/Oncology (iHOPE), Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
⁴ Department of Biostatistics, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁵ Department of Diagnostic and Interventional Radiology, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁶ Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁷ Division of Endocrinology, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁸ Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.

Abstract

Background: Few studies have evaluated predictive factors of isolated pituitary stalk thickening (iPST) in children.

Methods: In this retrospective study, radiology, endocrinology, and neuro-oncology databases were interrogated to identify patients with iPST between January 2000 and June 2019. A blinded, longitudinal assessment of MRIs was performed using quantitative, semi-quantitative, and qualitative metrics. Neuroimaging parameters were correlated to clinical parameters.

Results: Forty-seven patients were identified, with 40 meeting the inclusion criteria. Median age at baseline MRI was 9.6 years (range 0.9-17.5) with median follow-up of 5.2 years (range 0.3-18.6). Twenty-five (63%) were female. Thirty-four (85%) had pituitary dysfunction, including 31 with central diabetes insipidus (cDI). cDI was not predictive of proliferative disease (PfD): 69% of those with presumed primary hypophysitis (PPH) versus 93% with PfD (P = .1). Fourteen (35%) patients were diagnosed with PfD (germinoma = 8, Langerhans cell histiocytosis = 5, lymphoma = 1) at median of 1.3 years (range 0.3-4.0) after initial MRI. Progressive thickening of the stalk over time was associated with PfD (86% vs 4% in PPH, P < .0001), as was thickening of the entire stalk (56% in PfD vs 27% in PPH, P < .0001) with different imaging trends over time observed in PfD versus PPH. A "sack of marbles" appearance with heterogeneous enhancement on post-contrast imaging was associated with germinoma.

Conclusions: In this cohort, 35% of children with iPST were diagnosed with PfD. The association of cDI and PfD was not statistically significant. Progressive thickening of the entire stalk was predictive of PfD and a "sack of marbles" pattern was found to be highly suggestive of germinoma.

Keywords: CSF pleocytosis; LCH; germinoma; hypophysitis; pituitary stalk thickening.