The evolution in pituitary tumour classification: a clinical perspective

Abstract

Objective: Pituitary tumours comprise a pathologically and clinically diverse group of neoplasms. Classification frameworks have changed dramatically in the past two decades, reflecting improving understanding of tumour biology. This narrative review examines the evolution of pituitary tumour classification, from a clinical perspective. Results: In 2004, pituitary tumours were classified as ‘typical’ or ‘atypical’, based on the presence of markers of proliferation, Ki67, mitotic count and p53. In 2017, the new WHO marked a major paradigm shift, with a new focus on lineage-based classification, determined by transcription factor and hormonal immunohistochemistry. The terms ‘typical’ and ‘atypical’ were omitted, though the importance of proliferative markers Ki67 and mitotic count were acknowledged. The recent WHO 2022 classification incorporates further refinements, specifically recognising some less common types that may represent less well differentiated tumours. Whilst ‘high risk’ tumour types have been identified, further work is still required to improve prognostication. Conclusions: Recent WHO classifications have marked significant progress in diagnostic evaluation of pituitary tumours, though shortcomings and challenges remain for both clinicians and pathologists in managing these tumours.

Aggressive PitNETs and Potential Target Therapies: A Systematic Review of Molecular and Genetic Pathways

“…The recent update of the 2022 WHO PitNETs classification added the role of tumor cell lineages, distinguishing between immature and mature tumors of the PIT1 lineage and defining the inclusion features of the PIT1 lineage "family" [295]. Moreover, the analysis of antigens such as estrogen receptor alpha (ERα), members of zinc finger transcription regulatory auxiliary proteins (GATA3), and somatostatin receptor types 2 and 5 has recently been introduced as potential prognostic factors [295][296][297]. The 2022 WHO PitNETs classification integrated several pathology features to identify PitNETs with potential aggressive features.…”

Predicting the Consistency of Pituitary Macroadenomas: The Utility of Diffusion-Weighted Imaging and Apparent Diffusion Coefficient Measurements for Surgical Planning

“…Pituitary macroadenomas are tumors originating from the anterior lobe of the pituitary gland, and are defined by their substantial size (>10 mm in diameter). They can be classified as non-functioning (exerting mass effects) or functioning (producing excessive hormones) [ 1 , 2 ]. A typical feature is their propensity for suprasellar extension, which can lead to neurological symptoms that necessitate early intervention [ 3 ].…”

Trouillas’s Grading and Post-Surgical Tumor Residue Assessment in Pituitary Adenomas: The Importance of the Multidisciplinary Approach

“…Several classifications have been proposed to categorize PitNETs based on clinical, pathological, neuroimaging, morphological, and functional features [5][6][7][8][9]. One of the most comprehensive and currently used classification systems was proposed in 2020, incorporating a 5-level clinico-pathological combined approach.…”

“…One of the most comprehensive and currently used classification systems was proposed in 2020, incorporating a 5-level clinico-pathological combined approach. This system relies on factors such as tumor diameter, tumor morpho-functional types, lineage-restricted transcription factors, and grading based on invasion and proliferation criteria [5,9]. However, some studies have documented the value of only proliferation-invasiveness criteria in predicting tumor recurrence/progression, irrespective of endocrinological status and tumor size [10][11][12].…”