Diagnostic characteristics of sinonasal organizing hematomas: avoiding misdiagnosis

Organizing hematomas of the paranasal sinuses are diagnostic dilemmas clinically and radiographically, mimicking benign or malignant neoplastic processes and causing patients and clinicians undue worry regarding these diagnoses. Diagnostic criteria for correctly identifying these lesions are not well known.

A retrospective case series of 7 patients with sinonasal organizing hematoma was studied. Radiographic imaging, clinical characteristics, and pathology were reviewed for new insights.

Three patients presented with a primary complaint of epistaxis, 4 had masses visible on nasal endoscopy, and 2 had vascular malformations or small hemangiomas adjacent to the mass found on final pathology. Biopsy of these masses were consistently nondiagnostic prior to complete resection. The most diagnostic findings were "shells" of T2 hypointensity on magnetic resonance imaging (MRI) surrounding the lobules of each of the masses. These correspond to rims of fibrosis at the periphery of the lobules on pathology. Areas of fresh hemorrhage are located at the center of these lobules.

Sinonasal organizing hematomas are rare lesions of the paranasal sinuses whose clinical characteristics lead to misdiagnoses of benign or malignant neoplasms. Endoscopy, preoperative biopsy, and computed tomography (CT) imaging do not lend helpful information in differentiating these lesions from more worrisome neoplastic processes. However, MRI can lead to positive diagnosis by recognizing the distinct outer rims of T2 hypointensity typically seen in these lesions.