The Merkel cell carcinoma challenge
Notice bibliographique
Résumé
We read with interest the article by Bechert et al illustrating the challenge in diagnosing Merkel cell carcinoma (MCC) from fine-needle aspiration (FNA) samples.1 The authors discuss the role of immunohistochemistry in differentiating MCC from its mimics, and mention that immunostains may not help distinguish MCC from extrapulmonary small cell carcinomas that share a similar immunophenotype because both express dot-like cytokeratin 20 (CK20) positivity. We would like to add that since Merkel cell polyomavirus (MCPyV) is now known to be present in approximately 80% of cases of MCC,2, 3 the antibody CM2B4 that recognizes the large T antigen of MCPyV in MCC tissue specimens has proven to be diagnostically helpful.4 Indeed, CM2B4 has even been shown to distinguish MCC from high-grade primary parotid neuroendocrine carcinomas, which are similar with regard to cytomorphology and immunostaining pattern with dot-like expression of CK20.5 To the best of our knowledge, CM2B4 immunocytochemistry findings have not yet been reported in cytology material. Therefore, we would like to take this opportunity to briefly share our experience with CM2B4 immunocytochemistry. We initially used MCPyV-positive cell line xenograph induced MCC in mice to optimize immunohistochemistry. Immunostaining using 1:50 CM2B4 anti-MCPyV Large T antigen antibody (mouse monoclonal immunoglobulin G; Santa Cruz Biotechnology Inc, Dallas, Tex) was performed after heat-induced epitope retrieval (ethylenediamine tetraacetic acid buffer [pH 8.0]). Archival formalin-fixed paraffin-embedded cell block material from 6 FNA cases of MCC and 18 FNA controls (small cell carcinoma, non-MCC neuroendocrine tumor, small cell non-Hodgkin lymphoma, basaloid carcinoma, Ewing sarcoma, and melanoma) were used. Tissue resections in 10 cases of MCC were also studied. Clinical findings and other immunostaining results (specifically keratin, synaptophysin, and CK20) also were recorded. MCPyV T antigen staining was seen as staining was observed as nuclear positivity. All MCC cytology cases (average patient age, 66 years; 6 men and 1 woman) were obtained from metastases that demonstrated synaptophysin and CK20 dot-like immunoreactivity, and were positive for CM2B4 in 5 of 6 cell blocks (83%). The tumor cells also were positive in 5 of 10 tumor resections (50%). All control cases (average patient age, 63 years; 11 men and 7 women) were negative for CM2B4 except for staining of a few lymphoma cells in a lymphoplasmacytic non-Hodgkin lymphoma and infiltrating reactive lymphocytes in a high-grade non-MCC neuroendocrine tumor. These findings demonstrate that CM2B4 immunocytochemistry to detect MCPyV can be helpful to confirm the diagnosis of MCC. However, staining should be interpreted with caution because not all MCC tumor cells are immunoreactive. Moreover, CM2B4 staining may occasionally be detected in small reactive lymphocytes and some non-Hodgkin lymphomas, as has been previously reported.6 Dr. Pantanowitz has received royalties from Springer for a textbook entitled Cytopathology of Infectious Diseases. Dr. Pantanowitz has also received reimbursement from CAP for travel to the United States and Canadian Academy of Pathology, College of American Pathologists, and from ASCP for travel to American Society for Clinical Pathology meetings. Liron Pantanowitz, MD Sarah Navina, MD Sara E. Monaco, MD Department of Pathology University of Pittsburgh Medical Center Pittsburgh, Pennsylvania
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,001 |
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 tête enseignante, 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 ».