Clinical and Pathological Characteristics of Organized Hematoma

Objective. To study the clinical and pathological characteristics of patients with organized hematoma with malignant features in maxillary sinuses. Subjects and Methods. This was a retrospective study of five patients who were treated surgically for organized hematoma. The preoperative CT and MRI findings were studied clinically. The expressions of CD31, CD34, and periostin in surgical samples were investigated by immunohistochemistry. Results. The clinical features of organized hematoma, such as a mass expanding from the maxillary sinus with bone destruction, resembled those of maxillary carcinoma. However, CT and MRI provided sufficient and useful information to differentiate this condition from malignancy. Surgical resection was the first-line treatment because of the presence of a firm capsule. Characteristic histopathological findings were a mixture of dilated vessels, hemorrhage, fibrin exudation, fibrosis, hyalinization, and neovascularization. The expressions of periostin, CD31, and CD34 were observed in organized hematoma of the maxillary sinus. Conclusion. The expressions of periostin, CD31, and CD34 were observed in organized hematoma of the maxillary sinus. Organized hematoma is characterized pathologically by a mixture of bleeding, dilated vessels, hemorrhage, fibrin exudation, fibrosis, hyalinization, and neovascularization. CT and MRI show heterogeneous findings reflecting a mixture of these pathological entities. 1. Introduction Nonneoplastic hemorrhagic lesions causing mucosal swelling and bone destruction can develop in the maxillary sinus. This type of lesion was reported in the Japanese literature in 1917 as a “blood boil of the maxillary sinus” by Tadokoro and is comparatively well known in Japan as one of the differential diagnoses of maxillary carcinoma. However, in the English literature, this type of lesion tends to be referred to as hemangioma of the maxillary sinus, organized hematoma of the maxillary sinus, or organized hematoma of the maxillary sinus mimicking tumor [1–8]. Although their clinical manifestations are very similar, the relationships between these entities have not been described. We recently resected five such lesions and examined the associated clinical and histological features. Histologically, a combination of dilated vessels, hemorrhage, fibrin exudation, fibrosis, hyalinization, and neovascularization was characteristic. The lesion mimicked not only hematoma but also hemangioma. Therefore, either of the terms hemangioma or hematoma reflects the complete histological picture. In this paper, we report the