Osteoblastoma in the occipital bone: A case report of a rare tumor in the calvarium

The CT and MRI features of benign calvarium and skull base osteoblastoma

OBJECTIVE

We retrospectively reviewed the CT and MRI features of patients with benign osteoblastoma in the calvarium and skull base (CSBOB).

METHODS

Nine cases of pathologically confirmed benign CSBOB were analysed retrospectively. The patients had undergone CT and/or MRI. Tumour location, size, and imaging features were reviewed and recorded.

RESULTS

The patients included four males and five females with a mean age of 27.0 years (age 14-40 years). The tumours were located in the frontal bone in 3 patients, the occipital bone in 3 patients, and in the parietal bone, sphenoid bone, and skull base in 1 patient each. On CT, the tumours measured 5.1 ± 3.3 (1.8-8.4) cm. Seven tumours were shown to have caused expansile bony destruction with an eggshell appearance and varying degrees of calcification or matrix mineralization. Multiple septa were observed in 5 tumours. Intracranial growth was observed in 5 tumours. On MRI, 7 tumours showed heterogeneous hypo- to isointensity on T1WI. Heterogeneous high signal patterns with low signal rims and septa were observed in 6 tumours on T2WI, and 4 showed a fluid-fluid level. On contrast-enhanced imaging, 6 tumours showed peripheral and septal enhancement, and 2 showed the dural tail sign.

CONCLUSIONS

Benign CSBOB is a rare tumour characterized by expansile bony destruction, septa, a sclerotic rim and calcification or matrix mineralization on CT and MRI.

ADVANCES IN KNOWLEDGE

The findings from this study contribute to a better understanding of benign CSBOB and provide valuable imaging features that can aid in its diagnosis and differentiation from other tumours in the calvarium and skull base.

Imaging Findings and Clinical Features of Primary Spinal Epithelioid Hemangioendothelioma

Rationale and Objectives

Primary spinal epithelioid hemangioendothelioma (SEHE) is an extremely rare angiocentric vascular neoplasm with inherent metastatic potential, which pursues a clinical course intermediate between hemangioma and angiosarcoma. The present study sought to present computed tomography (CT) and magnetic resonance imaging (MRI) findings and clinical features of primary SEHE and review the literature.

Materials and Methods

Clinical data of four patients with primary SEHE confirmed by pathology from January 2011 to May 2020 were analyzed retrospectively. Two cases underwent CT scan, while 3 cases underwent MRI scan. Image observation included the tumor location, bone changes, morphology, density/signal characteristics, and enhanced features.

Results

The four patients were all women who ranged in age from 25 to 74 years. Four cases of the lesions were in the vertebral body; among them, two cases involved the accessory of the vertebra. Soap bubble appearance was detected in 2 cases, honeycomb osteolytic appearance in 2 cases, a sclerotic margin in 3 cases, and accompanying vertebral compression fracture in 1 case. CT showed a slightly inhomogeneous low density with punctate high-density foci. MRI showed an inhomogeneous low signal on T₁-weighted image (T₁WI) and a high signal on T₂WI. Contrast-enhanced CT/MRI demonstrated moderate to intensive inhomogeneous enhancement of the lesions. The discs were normal. In one case, lesions presented a dural tail sign.

Conclusions

Primary SEHE is so rare in the clinic as an aggressive vascular tumor. The relatively typical clinical features and radiographic findings can help in preoperative diagnosis.

Osteoblastoma of the breast:An uncommon and easily overlooked location

Osteoblastoma is a rare benign osseous neoplasm that accounts for 1%–3% of all primary bone tumors. Osteoblastomas can involve any part of the skeleton, but mainly occurs in the spine and other long bones, rarely in extra-skeletal areas. Extra-skeletal osteoblastomas arise from tissues outside of the bone, and only a few cases have been reported previously. To our knowledge, only one case of osteoblastoma in the breast has been described in the English literature. Here, we report another case of a breast osteoblastoma in a middle-aged woman, which was initially detected by ultrasound examination and digital mammography, and then was confirmed by histopathology. In this report, the imaging features and differential diagnosis of breast osteoblastoma are discussed.