Organizing Hematoma of the Maxillary Sinus Mimicking Malignancy Diagnosed by Fluorodeoxyglucose Positron-Emission Tomography (FDG PET/CT): A Case Report

Abstract

Organizing hematoma of the paranasal sinuses is a diagnostic dilemma clinically and radiographically, mimicking benign or malignant neoplastic processes. Although the diagnostic rate of this disease has increased as characteristic imaging findings are somewhat elucidated, endoscopic examination, preoperative biopsy, and computed tomography (CT) imaging do not give helpful information in differentiating these lesions from malignant neoplastic processes. A 55-year-old man presented with a 4-month history of recurrent nasal bleeding. He also complained of a left-sided nasal obstruction. CT findings were highly suggestive of a malignant tumor of the maxillary sinus. However, based on fluorodeoxyglucose F(18) positron-emission tomography (PET/CT) and magnetic resonance imaging (MRI), the provisional diagnosis of benign tumor rather than malignancy was made. Complete resection of the mass was achieved by simple transnasal endoscopic surgery using the Caldwell-Luc approach. Organizing hematoma of the maxillary sinus was diagnosed by histopathologic evaluation. The clinical, radiological, and histopathologic findings of the patient are presented. In this report, we have presented (18)FDG-PET findings of organized hematoma of the maxillary sinus (OHMS) that showed an increased FDG uptake in the peripheral rim of the mass with central photopenia. To our knowledge, this is the first case report in the literature reporting FDG-PET/CT findings of OHMS. Careful interpretation of metabolic (FDG-PET/CT) and anatomic (CT and MRI) images should be performed to accurately characterize the expansile lesion of the maxillary sinus in order to increase specificity and reduce equivocal findings significantly.

Keywords: Chronic Expanding Hematoma; Computed Tomography; Fluorodeoxyglucose F18 Positron-Emission Tomography; Magnetic Resonance Imaging; Maxillary Sinus; Organizing Hematoma.

Figure 1.. A 55-year-old man with a history of recurrent nasal bleeding and obstruction. After shrinkage of the inferior turbinate mucosa, we observed a lobulated pinkish mass in the inferior meatus that caused medial displacement of the inferior turbinate. (M: mass, S: septum, IT: inferior turbinate)

Figure 2.. Enhanced CT of the paranasal sinuses shows a 4.3 × 2.8 × 4.3 sized heterogeneous enhanced soft tissue mass in the maxillary sinus, the central region of which was in particular strongly enhanced (arrow head). The expansion of the maxillary sinus and bony thinning of the posterior and medial wall of the left maxillary sinus are also noted (black arrows). A, nonenhanced axial section. B and C, enhanced axial sections. D, enhanced coronal section. Also, CT scans showed the opacification of the sphenoid and ethmoid sinuses because of the mass obstructing the draining sinus ostia (asterisk).

Figure 3.. A, Axial T1-weighted T1-weighted MR image shows that the lesion is mostly isodense to the inferior turbinate interspersed with hyperintesity. B, Axial T2-weighted MR image shows marked heterogeneity of the lesion with a mix of hypointense (peripheral part), isointense, and hyperintense (central part) signals and a dark peripheral rim surrounding the lesion. C, Coronal, fat-suppressed, T2-weighted MR image shows the marked heterogeneity of the lesion with a mix of hypointense, isointense and hyperintense signals. A dark peripheral rim surrounding the lesion and a bright signal intensity due to mucosal inflammation of the involved maxillary sinus and ethmoid sinus (white arrows) is well demonstrated. D, Contrast-enhanced axial, fat-suppressed, T1-weighted MR image shows a marked papillary enhancement within the lesion.

Figure 4.. Integrated ¹⁸F-FDG-PET/CT images show moderate uptake only at the peripheral rim (black arrows) of the mass with negative FDG uptake in the central portion (asterisk). The maximum standardized uptake value (SUVmax) of this lesion is 3.80. Other signs of abnormal uptake suggesting a malignant lesion are not observed.