Rare oral metastasis from a probable large-cell neuroendocrine carcinoma of the lung

Rare métastase buccale d’un probable carcinome neuroendocrine pulmonaire à grandes cellules

¹ MD, Resident - Department of Oral Medicine and Oral SurgeryUniversity Hospital, Strasbourg, France
² MD, Fellow - Department of PathologyUniversity Hospital, Strasbourg, France
³ MD, Fellow - Department of Maxillofacial and Plastic SurgeryUniversity Hospital, Strasbourg, France
⁴ MD, PhD, Professor and Head of Department of Internal MedicineUniversity Hospital, Strasbourg, France
⁵ MD, PhD, Professor and Head of Department of Hematological OncologyUniversity Hospital, Strasbourg, France
⁶ MD, PhD, Professor and Head of Department of Otolaryngology-Head and Neck SurgeryUniversity Hospital, Strasbourg, France
⁷ DDS, PhD, Professor- Department of Oral Medicine and Oral SurgeryUniversity Hospital, Strasbourg, France
⁸ MD, PhD, Associate Professor – Department of Nuclear MedicineUniversity Hospital, Strasbourg, France
⁹ DDS, PhD, Associate Professor of Dental Faculty of Strasbourg – Head of Department of Oral Medicine and Oral Surgery, University Hospital, Strasbourg, France
¹⁰ INSERM UMR1109, Osteoarticular and Dental Regenerative Nanomedicine, Faculty of Medicine, FMTS, F-67085 Strasbourg, France

* Correspondence: beatrice.souron@hotmail.com

Received: 10 September 2015
Accepted: 30 November 2015

Abstract

Introduction: The prevalence of neuroendocrine tumors is 1/100 000 worldwide. Lung locations account for 25% and the oral cavity is very rarely involved. Observation: We reported the case of gingival hyperplasia around an upper molar in a patient with a medical history of lung adenocarcinoma treated by targeted chemotherapy. Incisional biopsy of the intraoral lesion revealed a large-cell neuroendocrine carcinoma (LCNEC). New imaging assessment revealed multiple metastasis locations of the lung disease. This case made us question the link between gingival LCNEC and the lung adenocarcinoma diagnosed through pleural cytology. Review of cytology findings did not make it possible to identify a neuroendocrine component among adenocarcinoma cells. Immunohistochemical tools sometimes help to differentiate primary from secondary lesions, but this was inconclusive here. Discussion: The literature shows that in cases of lung composite carcinoma, one component may be absent on small histology samples, and therefore on cytology. It was not possible either to rule out neuroendocrine carcinoma development under the effect of targeted chemotherapy. We considered the diagnosis of intraoral metastasis of a composite lung carcinoma which metastasized to its neuroendocrine component in the oral cavity. Conclusion: To our knowledge, this is the first case of LCNEC gingival hyperplasia revealing metastatic progression of lung adenocarcinoma.

Résumé

Introduction : La prévalence des tumeurs neurodendocrines est de 1/100 000 à travers le monde parmi lesquelles 25 % sont de localisation pulmonaire. Mais la localisation buccale est extrêmement rare. Observation : Il s’agissait d’une lésion gingivale hyperplasique autour d’une molaire maxillaire chez un patient présentant un antécédent d’adénocarcinome pulmonaire suivi et traité par chimiothérapie ciblée.L’analyse anatomopathologique de la lésion intra-orale montrait un carcinome neuroendocrine à large cellules (LCNEC). Un bilan d’imagerie révélait de multiples métastases de la tumeur pulmonaire. Ce cas nous interpelle sur le lien entre un LCNEC gingival et l’adénocarcinome pulmonaire diagnostiqué initialement à partir d’une cytologie pleurale. Le nouvel examen de cette cytologie n’a pas permis d’identifier une composante neuroendocrine parmi les cellules prélevées. L’immunohistochimie aide parfois à distinguer les lésions primaires des lésions secondaires, mais cette approche n’a pas été concluante dans ce cas. Discussion : La littérature montre que dans les cas de carcinomes pulmonaires composites, l’une des composantes peut être absente sur des échantillons de petite taille et donc a fortiori sur des cytologies. L’apparition d’un carcinome neuroendocrine sous les effets de la chimiothérapie ciblée n’est pas non plus exclue. Nous retenons le diagnostic de métastase buccale d’un carcinome pulmonaire composite qui a métastasé dans sa composante neuroendocrine. Conclusion : Il s’agit, à notre connaissance, du premier cas de LCNEC gingival révélant l’évolution métastatique d’un cancer pulmonaire.