A 2-year-old boy presented with his parents for evaluation of unilateral neck swelling that had persisted for 4 months. Examination revealed a firm, immobile, and nontender mass affixed to the underlying right mandible. Magnetic resonance imaging (MRI) showed a 3.7 × 3.6 × 2.6-cm mass arising from the medial aspect of the right mandibular body with cortical destruction (Figure, A-C). The mass extended into the submandibular and sublingual spaces. Magnetic resonance imaging demonstrated a lesion isointense to muscle on T1 sequence, heterogeneously hyperintense with internal foci of decreased intensity on T2 sequence (Figure, D), and homogeneous contrast enhancement. Results from staging studies, including a bone survey, were negative for metastatic disease. Core biopsy revealed spindle cell proliferation with abundant intervening collagen but no anaplasia, mitotic activity, eosinophils, or inflammatory components. Incisional biopsy showed fibroblastic proliferation comprised of slender, uniform spindle cells arranged in fascicles with intervening collagenous stroma and no mitoses. Results from immunohistochemical analysis were positive for β-catenin and negative for CD34, desmin, and smooth muscle actin. No clonal abnormalities were present. The patient was negative for familial adenomatous polyposis (FAP) mutations on genetic testing. Chemotherapy with hydroxyurea, 20 mg/kg/d, was initiated and continued for 2 years. Reconstructive surgery was considered but not pursued given the lesion size. The most recent interval MRI, performed 4 years after initial presentation, showed a decrease in the size of the mass to 1.5 cm in the maximum dimension.
Clark CM, Bann DV, Zacharia TT. Unilateral Neck Swelling in a Pediatric Patient. JAMA Otolaryngol Head Neck Surg. 2017;143(4):423-424. doi:10.1001/jamaoto.2016.3015