Vasculogenic mimicry in non‐functioning pituitary adenomas: fact or fallacy?
Notice bibliographique
Résumé
Introduction Vasculogenic mimicry (VM) refers to the formation of vascular channels within genetically dysregulated tumor cells. It occurs de novo without the presence of an endothelial cell lining. Since its introduction in 1999, it has been observed in several tumor types and is proposed to be an alternative means of providing blood perfusion to tumors. Pituitary tumors are generally slow growing, benign adenomas. To date, VM in pituitary adenomas has not been described. Herein, we studied whether these channels occur in clinically non‐functioning pituitary adenomas (NFPA). Materials and Methods We studied the presence of VM in 49 randomly selected cases of surgically‐removed clinically NFPA using CD34 and Periodic Acid‐Schiff (PAS). Tumors were divided into 2 groups (19 recurring and 30 non‐recurring). 10 surgically removed and 5 autopsy‐obtained non‐tumorous pituitaries from patients with no endocrine diseases and no hormone treatment were also included. To demonstrate vascular change, CD34‐PAS double immunostaining on paraffin‐embedded sections was used. Slides were assessed for the presence of CD34‐negative and PAS‐positive channels indicating that they were not lined by endothelial cells. Immunohistochemical findings were evaluated under low and high magnification. Results Immunopositivity for CD34 demonstrated endothelial cells lined blood vessels, which were localized in all 49 cases of clinically NFPA. The PAS‐ positive pattern, which stained sub‐endothelial matrix, was also visible in all cases. Slides were assessed for the presence of CD34‐negative and PAS‐positive channels indicating that they were not lined by endothelial cells. This staining pattern suggestive of VM was observed in 22/49 (45%) of the clinically NFPA. The amount of staining pattern varied both from case to case and within groups. No statistically significant correlation was found between the presence of this staining pattern within each group and the gender of the patients. An intriguing finding was the correlation between staining pattern and age. In 22 cases studied where the staining was identified, 14 cases (64%) were in the age range between 52–59 yrs while the remainder of the cases were equally distributed between the age range 25–75 yrs. In 27 cases where the staining pattern was not identified, 12 cases (44%) were in the age range between 51–57 yrs and 22/27 (81%) of the negative cases in the age range between 31–57 yrs. This was an intriguing finding since cases studied were randomly selected. Conclusion This finding carries potential clinical implications with respect to patient response to therapy as well as clinical course. More work is needed to prove that the presence of sub‐endothelial matrix without endothelial lining represents VM. Support or Funding Information Acknowledgement Authors are grateful to the Jarislowsky and Lloyd Carr‐Harris Foundations for their generous support.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,006 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,002 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».