A Huge Intraosseous Hemangioma in the Maxillary Sinus Misdiagnosed as Osteosarcoma: A Case Report

Article information

J Rhinol. 2026;33(2):126-130

Publication date (electronic) : 2026 July 31

doi : https://doi.org/10.18787/jr.2026.00012

So Hee Kang, MD, Myeong Sang Yu, MD, PhD

Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea

Address for correspondence: Myeong Sang Yu, MD, PhD, Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea, Tel: +82-2-3010-3710, Fax: +82-2-489-2773, E-mail: dryums@gmail.com

Received 2026 March 26; Revised 2026 May 5; Accepted 2026 May 18.

Abstract

INTRODUCTION

Intraosseous hemangiomas (IOHs) are benign vascular tumors that arise from bone and account for less than 1% of all bone tumors [1,2]. In the head and neck region, they occur more frequently in the orbit, scalp, and oral cavity, whereas involvement of the nasal cavity and paranasal sinuses is exceedingly rare [2]. IOHs typically present in the fourth or fifth decade of life [1,3]. Although they are generally slow-growing and clinically indolent, rare cases with atypical or more aggressive-appearing radiological features have been reported [4]. In the paranasal sinuses, these atypical features may mimic malignant bone tumors such as osteosarcoma, resulting in radiological–pathological discordance, diagnostic confusion, and challenging treatment planning.

Complete surgical excision is generally considered the treatment of choice for IOHs, particularly when the lesion is symptomatic or anatomically accessible [2,5]. However, when a benign lesion has malignant-appearing radiological features, misdiagnosis may lead to inappropriate treatment planning, including unnecessarily extensive intervention for a benign lesion or delayed definitive management of an occult malignancy. We report a rare case of a very large IOH of the maxillary sinus that was preoperatively suspected to be osteosarcoma because of marked radiological–pathological discordance.

CASE REPORT

An 18-year-old man presented with a 2-month history of right-sided nasal obstruction and a 2-week history of right-sided bloody rhinorrhea. Nasal endoscopy revealed bulging of the right lateral nasal wall that appeared to originate from the maxillary sinus.

Computed tomography (CT) demonstrated a large expansile calcified mass occupying the right maxillary sinus, with internal septal and peripheral rim calcifications, focal posterior maxillary wall erosion, and extension toward adjacent structures, including the ethmoid sinus and pterygopalatine fossa (Fig. 1). Magnetic resonance imaging (MRI) revealed a 4.5× 4.5×4.6 cm expansile lobulated mass with homogeneous low signal intensity on T1-weighted images, heterogeneous high signal intensity on T2-weighted images, internal low-signal foci corresponding to calcification, and progressive enhancement on dynamic contrast imaging (Fig. 2). Based on the patient’s young age and the radiological features of a bulky calcified osseous lesion with strong enhancement, focal bone erosion, and extension toward adjacent structures, osteosarcoma or juvenile ossifying fibroma was initially suspected.

Fig. 1

Head and neck CT images at the first visit. A: Noncontrast axial CT image. B: Contrast-enhanced axial CT image. C: Contrast-enhanced coronal CT image. CT, computed tomography.

Fig. 2

Head and neck magnetic resonance images at the first visit. A: Coronal T1-weighted image. B: Axial T1-weighted image. C: Coronal T2-weighted image. D: Axial T2-weighted image. E: Contrast-enhanced coronal T1-weighted image. F: Contrast-enhanced axial T1-weighted image.

To obtain pathological confirmation, an endoscopic biopsy was performed. Histopathological examination demonstrated woven bone with branching fibrous stroma and spindle cell morphology (Fig. 3A). Immunohistochemical staining for mouse double minute 2 homolog and cyclin-dependent kinase 4 was negative, making osteosarcoma less likely in the limited biopsy specimen and favoring a low-grade fibro-osseous lesion, such as fibrous dysplasia. Despite the biopsy results, the radiological findings remained discordant with fibrous dysplasia. On multidisciplinary review, the lesion lacked the typical homogeneous expansile remodeling and ground-glass matrix expected in fibrous dysplasia but demonstrated internal calcification, avid enhancement, focal posterior maxillary wall erosion, and lateral extension toward the pterygopalatine fossa and sphenopalatine foramen. Therefore, a low-grade malignant bone-forming tumor, particularly osteosarcoma, could not be confidently excluded. After multidisciplinary discussion, definitive surgical excision was recommended because malignancy could not be confidently excluded despite the biopsy findings. The patient and his family were informed that additional surgery might be required depending on the final pathological diagnosis. Accordingly, right-sided endoscopic medial maxillectomy was performed for definitive diagnosis and treatment, along with management of secondary sinusitis.

Fig. 3

Gross, histopathological, and immunohistochemical findings of intraosseous venous hemangioma. A: Histological examination of the preoperative endoscopic biopsy specimen showing woven bone with a branching pattern and fibrous stroma. B: Gross surgical specimen demonstrating bony trabeculation and a sponge-like appearance consistent with an osseous lesion. C: Histological examination of the resected surgical specimen, revealing prominent congestion and a proliferative vascular lesion (hematoxylin and eosin stain). D: Immunohistochemical staining positive for CD31, highlighting endothelial-lined vascular channels. E: Immunohistochemical staining positive for CD34, further confirming the vascular nature of the lesion. Staining for CD31 and CD34 highlights distinct vascular structures, confirming the diagnosis of intraosseous venous hemangioma.

The procedure included partial resection of the right inferior turbinate with preservation of the turbinate head, partial middle conchotomy, anterior-to-posterior ethmoidectomy, and resection of the medial maxillary wall. Intraoperatively, the mass was centered on the medial wall of the right maxillary sinus and appeared well circumscribed. The overlying mucosa was thinned but preserved, and no gross invasion of adjacent soft tissue was identified. Grossly, the specimen was fragmented and had a sponge-like appearance, with abundant blood components suggestive of a vascular lesion (Fig. 3B). Frozen-section analysis showed an atypical lesion but no definite evidence of malignancy.

Final histopathological examination revealed a congestive, proliferative vascular lesion admixed with bony trabeculae. Immunohistochemical staining for CD31 and CD34 highlighted the vascular architecture, confirming the diagnosis of intraosseous venous hemangioma (Fig. 3D and E). On subsequent radiological–pathological correlation, the lesion’s T2 hyperintensity, progressive enhancement pattern, and relatively well-defined rim-contained growth pattern were considered more compatible with IOH than with osteosarcoma.

Postoperative MRI and CT surveillance, followed by serial endoscopic examinations, demonstrated no evidence of recurrence or disease progression over more than 3 years.

DISCUSSION

IOH is a rare benign vascular tumor of bone, and involvement of the nasal cavity or paranasal sinuses is particularly uncommon [2,3]. Because the location is unusual and presenting symptoms are often nonspecific, preoperative diagnosis can be challenging, especially when radiological and histopathological findings are discordant.

Complete surgical excision is generally considered the treatment of choice for IOHs, and recurrence is uncommon after complete resection [2,5]. Nevertheless, recurrence has been reported in selected cases. Park and Lee [5] described a recurrent maxillary intraosseous cavernous hemangioma in a 12-year-old girl in whom complete excision was limited by adjacent dentition. In that case, conservative management with curettage and sclerotherapy achieved favorable long-term control, suggesting that treatment strategies may need to be individualized according to anatomical and functional considerations [5]. In the present case, endoscopic medial maxillectomy was selected because the lesion was centered on the medial wall of the maxillary sinus and malignancy could not be confidently excluded preoperatively; this approach enabled both definitive diagnosis and complete resection. No recurrence has been observed during more than 3 years of postoperative imaging and endoscopic follow-up, supporting the adequacy of complete endoscopic resection in this anatomically favorable case.

Clinically, IOHs involving the nasal cavity or maxillary sinus may present with nasal obstruction, epistaxis, diplopia, exophthalmos, or sinusitis, depending on tumor size and extent [2,3]. Radiologically, these lesions classically demonstrate a well-defined honeycomb or sunburst pattern on CT, reflecting trabeculated bony architecture [2,3]. MRI findings often include high signal intensity on T2-weighted images and progressive enhancement after contrast administration, reflecting the vascular nature of the tumor [2]. However, these classic imaging features may be obscured when a lesion is bulky, contains prominent calcified or ossified components, or shows focal bone erosion. In such cases, a benign IOH may mimic a malignant bone-forming tumor on imaging.

In the present case, several factors contributed to the preoperative diagnostic difficulty. The lesion arose in an unusual sinonasal location, occurred in a young patient, and had malignant-appearing radiological features, including internal calcification, avid enhancement, focal posterior maxillary wall erosion, and lateral extension toward the pterygopalatine fossa and sphenopalatine foramen. These findings raised concern for a malignant bone-forming tumor, particularly osteosarcoma. In addition, the initial endoscopic biopsy yielded limited tissue from the lesion margin and favored a low-grade fibro-osseous lesion, creating radiological–pathological discordance. A definitive diagnosis was established only after complete surgical excision. Although IOHs are classically described in middle-aged adults, rare cases in younger patients have also been reported [4,5]. Because few cases have been reported, whether younger age is associated with a more atypical or malignant-appearing radiological presentation remains unclear. Nevertheless, the present case suggests that IOH should not be excluded solely on the basis of young age when evaluating a malignant-appearing sinonasal lesion.

From a differential diagnostic standpoint, fibrous dysplasia was considered less likely because the lesion lacked the typical ground-glass matrix and homogeneous expansile remodeling expected in fibro-osseous disease. Osteosarcoma remained a concern because of the bulky calcified osseous component, focal posterior wall erosion, and strong enhancement, although the final diagnosis showed that these malignant-appearing findings may also occur in atypical IOH.

Similar diagnostic challenges have been reported in the sinonasal region. Kim et al. [3] described an IOH arising from the middle turbinate that was initially misdiagnosed as chronic rhinosinusitis with nasal polyps because of nonspecific endoscopic, radiological, and biopsy findings. Together, these cases highlight the diagnostic ambiguity associated with sinonasal IOHs.

In conclusion, IOH should be considered in the differential diagnosis of malignant-appearing sinonasal masses, even in young patients. When radiological findings and biopsy results are discordant, multidisciplinary evaluation is essential to reduce diagnostic error and guide appropriate treatment planning.

Article information Continued