Pituitary adenomas with multiple cell lineage combinations: clinicopathological features and short-term prognosis

There are few published data concerning pituitary adenomas (PAs) derived from multiple lineages. In this study the authors aimed to determine the clinicopathological characteristics and prognostic profiles of PAs with multiple cell lineage combinations (PAwMCs).

The authors reviewed data on 723 patients with PAs who had undergone surgery between 2018 and 2021 and identified 93 cases (12.9%) of PAwMC. They collected detailed data on these cases, including clinical information, pathological features, and prognosis. From among 589 cases of PAs with only one cell lineage (PAwOCs), they randomly selected 100 cases to investigate differences between the two tumors. To enable investigation of the characteristics of different subgroups, they further subclassified PAwMCs into 4 groups according to the following specified combinations of pituitary-associated transcription factors: group A, immunopositive for pituitary-specific positive transcription factor 1 (Pit1) and steroidogenic factor 1 (SF1); group B, immunopositive for Pit1 and T-box transcription factor (Tpit); group C, immunopositive for SF1 and Tpit; and group D, immunopositive for Pit1, SF1, and Tpit.

Compared with PAwOC, PAwMC was more often associated with hormone hypersecretion (31.0% vs 50.0%, p = 0.037) and had worse short-term prognoses with lower complete response rates (58.7% vs 30.0%, p = 0.026) and more postoperative complications (19.4% vs 35.9%, p = 0.041). Each of the 4 PAwMC subgroups had its own clinical features. Overall, PAwMCs displayed more neurological manifestations than evidence of hypersecretion, which may be attributable to a disparity between pituitary-associated transcription factors and endocrine-related manifestations. Moreover, multiple cell lineages, tumor size (p = 0.011), and Knosp grade (p = 0.013) were all found to be critical predictors of the prognosis of PAwMC.

The authors described a special subtype of PAs, which derived from multiple lineages. They found a unique effect of the combination of distinct cell lineages on PAs and present detailed clinicopathological and prognostic profiles of these special PAs. These data will contribute to a more comprehensive view of PAs and assist in the selection of treatment.