Hidden Cartilage in the Tonsil: A Rare Case of Cartilaginous Choristoma

Abstract

Background: Choristomas are benign proliferations of histologically normal tissue in ectopic locations. While osseous and cartilaginous choristomas are known in the oral cavity, their occurrence in the palatine tonsil is exceptionally rare. This report highlights a rare case of tonsillar cartilaginous choristoma with osseous metaplasia—an uncommon finding with diagnostic implications.

Case Presentation: A 38-year-old male presented with recurrent sore throat and fever, consistent with chronic tonsillitis. Bilateral tonsillectomy was performed. Gross examination revealed grey-white glistening tissue with firm-to-hard consistency. Histopathology of both tonsils showed lymphoid tissue with acanthotic stratified squamous epithelium and follicular hyperplasia. Within the fibrocollagenous stroma, mature hyaline cartilage lobules were observed along with foci of calcification and osseous metaplasia—hallmarks of a cartilaginous choristoma with endochondral ossification.

Discussion: Cartilaginous choristoma of the palatine tonsil is rarely reported, with fewer than 10 cases documented in the literature. Theories for its pathogenesis include developmental anomalies from the second pharyngeal arch or reactive mesenchymal proliferation due to chronic inflammation. Differentiation from neoplastic lesions is crucial, as misdiagnosis can lead to overtreatment. This case highlights the importance of routine histopathological evaluation of tonsillectomy specimens, even in seemingly benign conditions.

Conclusion: This case adds to the limited literature on tonsillar choristomas and highlights the potential for osseous differentiation within these lesions. Early recognition is essential to avoid diagnostic pitfalls and ensure appropriate patient management.