Rhinology and Otology

Biography

Biography: Dr. Alka Ashmita Singhal

Abstract

A case of unusually large brown tumour of mandible mimicking cherubism in a patient with chronic kidney disease with tertiary hyperparathyroidism. Clinical Details: A 41 year male, of short stature and short neck, presented in Head and Neck Oncosurgery with a grossly enlarged and protruding lower jaw, open mouth with chronic kidney disease on dialysis. Patient was immobile and limited to wheelchair.  Biochemical Investigations: Serum Calcium 10.2mg/dL. Serum PTH was 4808.0 pg/mL & 25–OH Vitamin D 16.3 g/mL. Sestamibi scan showed left inferior parathyroid adenoma (below the lower pole of left thyroid gland). Ultrasound in addition to sestamibi showed all the four enlarged parathyroids as hypoehoic nodules in their normal location behind the thyroid with characteristic arc of vascularity. Chest X Ray: showed gross cardiomegaly. Bilateral clavicles, scapula, humerus and multiple ribs showed mixed lytic and sclerotic areas. Calcification of the trachea and bilateral bronchi was seen Echocardiography: showed global left ventricular hypokinesia with paradoxical septal motion, thickened and calcific mitral valve leaflet with moderate MR (mitral regurgitation) Radionuclide Bone Scan (20mCiof Tc-99m MDP): showed focal abnormal uptake in the grossly enlarged mandible and maxilla. Increased uptake also noted in calvarium. CT Facial Bones  Generalised increased bone density with multiple lytic and sclerotic lesions in all bones of skull. Gross expansion and marked thinning of cortex of bilateral maxilla, causing narrowing of the nasopharynx and nasal cavities. The expanded mandible displacing the tongue posteriorly and causing narrowing of oropharynx and hypopharynx. Significant destruction of the alveolar arches in maxilla and mandible was seen giving a “ floating appearance to the teeth”. Discussion: With the enlarged mandible and floating teeth appearance cherubism was initially considered as a differential diagnosis. Cherubism is a rare genetic childhood disorder which causes enlargement of the lower part of face due to  abnormal growth of the mandible and maxilla, where the bone enlarges and is replaced by cysts. It is considered as a variant of fibrous dysplasia. With further imaging the generalised metabolic abnormality of bones is suggested. In view of markedly raised parathormone levels, brown tumors in maxilla and mandible is likely diagnosis. Histopathology showed fibrocollagenous tissue admixed with irregular spicules of woven trabecular bone. Multple multinucleated osteoclastic type giant cells are seen. Foci of calcification seen. Findings consistent with brown tumor syndrome.