Soft Tissue Special Issue: Chondroid Neoplasms of the Skull

Bone Formation in Pleomorphic Adenoma: A Case Report

Pleomorphic adenoma is a benign tumour with variable cytomorphological and architectural elements. It is the most common salivary gland tumour in children and adults. We report a case of a 32-year-old Malay woman who presented with a slow-growing, painless, firm, and mobile nodule of 1 cm x 1 cm in size at the angle of her mandible on the right side which could be palpated bimanually. Intraorally, this nodule could be palpated at the retromolar area. On excisional biopsy, this nodule was reported as a pleomorphic adenoma with predominant chondroid stromal elements and a large area of bone formation in the stroma. We discuss the possible pathogenesis, differential diagnosis, and clinical significance of this exceptionally rare phenomenon of bone formation in pleomorphic adenoma in minor salivary glands with the literature review. The clinical significance and relevance on treatment outcome for pleomorphic adenoma with bone formation is currently uncertain as there are only a few cases reported in the literature. A good follow-up study is recommended to assess the clinical significance of pleomorphic adenoma with extensive bone formation.

Imaging features of cartilaginous tumors of the head and neck

There is a wide spectrum of head and neck cartilaginous lesions which include both neoplastic and nonneoplastic processes. Cartilaginous tumors of the head and neck are uncommon, posing a diagnostic challenge. Benign cartilaginous tumors that may occur in the head and neck include chondroma, chondroblastoma, chondromyxoid fibroma, osteochondroma, and synovial chondromatosis. Chondromesenchymal hamartoma is a rare non-neoplastic cartilaginous lesion that is included for the 1first time in the new WHO classification and radiologically can mimic a tumor. Malignant cartilaginous tumors include chondrosarcoma and chondroid variant of chordoma. Characteristic tumor locations, internal chondroid matrix calcification, and typical T2 hyperintense signal secondary to high-water content within the extracellular matrix of the hyaline cartilage are useful imaging features that narrow the differential diagnosis and help in diagnosing these diseases. This article presents a narrative review of the anatomy of the head and neck cartilaginous structures, discusses the current knowledge and imaging spectrum of benign and malignant cartilaginous tumors and tumor-like lesions of the head and neck.