Head and Neck Pathol (2009) 3:174–178 (serum) 2.9 mg/dl (normal 2.5–4.5 mg/dl), albumin 5.1 (normal 3.7–5.1 g/dl), urine calcium level of 6.4 mg/dl (normal, not established), and urine 24 h calcium 185.4 mg/ 24 h (normal 100.0–300.00 mg/24 h). Other laboratory values were within normal limits, except for a bilirubin of 1.8 mg/dl (normal 0.1–1.2 mg/dl). The patient had known Gilbert’s syndrome. The patient’s clinical appearance was phenotypically normal, not that of Noonan’s syndrome. Although we are uncertain what testing was performed, a comprehensive workup revealed the patient was negative for Noonan’s syndrome and hyperparathyroidism. On magnetic resonance imaging (MRI), two lesions were seen (see Fig. 1). The lesions were heterogeneously hyper- intense on T2 weighted imaging and isointense to brain on T1 weighted imaging with enhancement. The larger of the two recurrent lesions was 3.1 9 2.9 9 2.6 cm encompass- ing the roots of the maxillary posterior teeth and deviating the inferior turbinate (see Fig. 2). The second lesion was 2.4 9 2.3 9 2.1 cm and was located inferior to the medial ﬂoor of the left orbit. Invasion of the medial wall of the left maxillary sinus with bulging into the nasal cavity and thin- ning of the posterolateral maxillary sinus wall with tumor bulging into the retromaxillary fat pad was seen. A left endoscopic ethmoidectomy was performed using an image guidance mask. The recurrent left maxillary giant cell granuloma (GCG) was excised via intraoral approach. The maxillary lesion was removed, followed by stripping of the maxillary sinus mucosa to bone. The maxillary sinus 175 Fig. 2 T2 weighted MRI of the larger inferior lesion on coronal section demonstrating deviation of inferior turbinate was reconstructed with demineralized bone matrix and autogenous platelet rich plasma. The two pathology specimens from the left ethmoid region and maxillary sinus were histologically similar, revealing abundant diffusely distributed multinucleated central giant cells (see Fig. 3). The hypercellular ﬁbrous stroma was composed of mononuclear spindle shaped cells and scattered ovoid cells. Cystic areas of extravasated nonendothelialized hemorrhage, resembling an aneurysmal Fig. 1 T1 weighted MRI of the tumors on sagittal section demon- strating proximity to the dentition and the ethmoid region Fig. 3 Photomicrograph from ﬁrst recurrence of the left maxillary CGCG showing multinucleated giant cells in a spindle or ovoid shaped ﬁbrovascular connective tissue stroma (H&E, 910)