Calcified Chondroid Mesenchymal Neoplasm of the Masticator Space: A Case Report.

Calcified chondroid mesenchymal neoplasm (CCMN) is a rare, recently defined tumor characterized by mesenchymal tissue with chondroid features and calcification. It typically harbors an FN1 fusion and shows a predilection for the temporomandibular joint and distal extremities. CCMN is benign and has not been associated with malignant behavior. We present the case of a 61-year-old woman with an eight-year history of a progressively enlarging, palpable mass in the left parotid region, associated with ipsilateral hearing loss and facial palsy. Imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI), revealed a well-defined tumor located between the left masseter muscle and parotid gland, extending into the left supratemporal fossa. The lesion exhibited heterogeneous soft tissue density with irregular intratumoral calcifications and moderate contrast enhancement. Ultrasound demonstrated a hypo- to isoechoic nodular lesion within the left parotid gland. Histopathological evaluation, in correlation with imaging findings, confirmed the diagnosis of CCMN. Surgical excision was performed, and postoperative imaging showed no residual tumor. This case highlights the importance of considering CCMN in the differential diagnosis of calcified soft tissue tumors in the head and neck region.