IDH mutation status in a series of 88 head and neck chondrosarcomas: different profile between tumors of the skull base and tumors involving the facial skeleton and the laryngotracheal tract

Matthias Tallegas (1) , Elodie Miquelestorena-Standley (2, 1) , Corinne Labit-Bouvier (3) , Cécile Badoual (4, 5) , Arnaud François (6, 7) , Anne Gomez-Brouchet (8) , Sébastien Aubert (9) , Christine Collin (10) , Anne Tallet (10) , Gonzague de Pinieux (11, 1, 2)

1 CHU Trousseau [APHP]
2 UT - Université de Tours
3 service hospitalier d'anatomie et cytologie pathologique humaine, APHM, Marseille
4 HEGP - Hôpital Européen Georges Pompidou [APHP]
5 UFR Médecine UPCité - UFR Médecine [Santé] - Université Paris Cité
6 Service d'Anatomie et Cytologie Pathologique [CHU Rouen]
7 ESCAPE - Epidémiosurveillance de protozooses à transmission alimentaire et vectorielle
8 CHU Toulouse - Centre Hospitalier Universitaire de Toulouse
9 CHU de Lille - Centre Hospitalier Universitaire de Lille
10 CHRU Tours - Centre Hospitalier Régional Universitaire de Tours
11 Phy-Os - Sarcomes osseux et remodelage des tissus calcifiés - Phy-Os [Nantes - INSERM U1238]

Chondrosarcomas are rare primary malignant bone tumors that involve the head and neck region in 1% to 12% of cases. Central conventional chondrosarcoma is the most common subtype and is associated with isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) gene mutations in 50% to 60% of cases. We aimed to define the frequency of IDH1 and IDH2 gene mutations in a multicenter series of 88 cases of chondrosarcoma of the head and neck, including tumors involving the base of the skull (n = 30), the facial skeleton (n = 11), and the laryngeal and tracheal cartilages (n = 47). Petrous bone and cricoid cartilage were the most frequently involved sites for chondrosarcomas of the skull base and laryngotracheal tract (43.3% and 31.9%, respectively). Overall, 64.9% of craniofacial chondrosarcomas featured IDH mutations, with a high rate for skull base tumors (85.7%) but no IDH mutations in tumors of the facial skeleton. This different mutational profile could be related to the type of ossification, the bones of the base of the skull mainly resulting from endochondral ossification, and those of the face from intramembranous ossification. Conversely, mutation was infrequent in chondrosarcomas involving the laryngeal and tracheal cartilages (11.8% of 47 cases). Evaluation of IDH mutation status may be a useful diagnostic tool for bone tumors of the skull base, which are most often assessable with only small biopsy samples. The low rate of IDH mutations observed in laryngotracheal chondrosarcomas suggests a different mode of tumorigenesis needing further exploration.

Mots clés: Head and neck; Skull base; Molecular pathology; IDH; Chondrosarcoma; Facial skeleton; Laryngotracheal tract

Domaines: Sciences du Vivant [q-bio]

Matthias Tallegas, Elodie Miquelestorena-Standley, Corinne Labit-Bouvier, Cécile Badoual, Arnaud François, et al.. IDH mutation status in a series of 88 head and neck chondrosarcomas: different profile between tumors of the skull base and tumors involving the facial skeleton and the laryngotracheal tract. Human Pathology, 2019, 84, pp.183-191. ⟨10.1016/j.humpath.2018.09.015⟩. ⟨hal-02316608⟩