Primary lymphoma of the skull base

CT, conventional, and functional MRI features of skull lymphoma: a series of eight cases in a single institution

OBJECTIVE

With the hypothesis that the combination of CT, conventional, and functional MRI can indicate a possible diagnosis of skull lymphoma, this study aimed to systematically explore CT, conventional, and functional MRI features of this rare entity.

MATERIALS AND METHODS

This retrospective study included eight patients with pathologically confirmed skull lymphomas. CT and conventional MRI findings, including the location, size, attenuation/signal intensity, cystic/necrosis, hemorrhage, calcification, enhancement, skull change, brain parenchyma edema and adjacent structure invasion, were reviewed. We also reviewed multi-parametric functional MR imaging features obtained from diffusion-weighted imaging (DWI, n = 4), susceptibility-weighted imaging (SWI, n = 3) and dynamic susceptibility-weighted contrast-enhanced perfusion-weighted imaging (DSC-PWI, n = 1).

RESULTS

The eight patients in this series consisted of five males and three females, with a mean age of 51.1 years. All skull lymphomas showed the tumors extending to extra- and intra-cranial spaces with permeative destruction of the intervening skull. Intratumoral cystic/necrosis was seen in one case. Hemorrhage or calcification was absent. Dural mater infiltration was detected in all cases. Two clivus lymphomas encased internal carotid artery without narrowing the lumen. Three cases invaded brain parenchyma with moderate edema. The tumors demonstrated high signal on DWI with low ADC values comparing to muscles. SWI images showed little intratumoral hemorrhage and vessel. Low relative cerebral blood volume (rCBV) value was detected.

CONCLUSIONS

Skull lymphomas commonly presented as a homogenous solid tumor extending either intra- or extra-cranially with permeative bone destruction. Restricted diffusion, little intratumoral susceptibility signal, and lower perfusion may indicate a specific diagnosis. Multi-parametric functional MRI may be a promising tool for the diagnosis of skull lymphomas.

Primary Lymphoma of the Skull Base in the Chinese: Clinical, Radiological, Pathological, and Therapeutic Experience in a Series of 8 Patients

BACKGROUND

Primary lymphoma of the skull base (PLSB) is an extremely rare neoplasm and not much is known regarding the clinical features of, treatment strategies for, and prognoses of these lesions. We investigated the manifestations and clinical outcomes of Chinese patients with PLSB.

METHODS

We retrospectively reviewed the data from 8 consecutive patients with PLSB who had been treated at our center from October 2008 to December 2016 and analyzed their clinical features, treatment strategies, and prognoses.

RESULTS

Of the 8 patients, 3 were men and 5 were women, with a male/female ratio of 0.6. The median age was 53.5 years. In most instances, the onset was characterized by headache, followed by dysfunction of the cranial nerves. The most frequently affected region was the cavernous sinus. On magnetic resonance imaging, the main characteristic was that the internal carotid artery was encased by the tumor without an obvious tendency to be deformed, dislocated, or narrowed. All patients underwent surgical biopsy via a transsphenoidal or sublabial-transmaxillary approach. The pathological diagnosis was non-Hodgkin lymphoma for all 8 patients, with diffuse large B-cell lymphoma in 7 patients. The patients underwent chemotherapy and involved-field radiotherapy. The median overall survival was 52 months, and the 1-year progression-free survival rate was 87.5%.

CONCLUSIONS

PLSB is a rare disease and a diagnostic challenge, with most cases in the Chinese due to diffuse large B-cell lymphoma. We found that the incidence peaked in middle and old age, and the cavernous sinus was usually affected. Multidisciplinary treatment involving surgical biopsy, chemotherapy, and radiotherapy was an effective therapeutic strategy.

Central skull base lymphoma in children: MR and CT features

BACKGROUND

Central skull base tumours are rare in children.

OBJECTIVE

To characterize the imaging features of central skull base lymphoma in children to aid its diagnosis.

MATERIALS AND METHODS

The authors reviewed the CT findings (available in three patients) and MR findings (available in four patients) in four patients (three boys, one girl; age 2-12 years) with pathologically proven lymphoma (two with Burkitt lymphoma, two with B-cell lymphoma) involving the central skull base. Tumour location and extent, MRI signal intensities, noncontrast CT attenuation, patterns of enhancement, and changes in adjacent structures were evaluated.

RESULTS

All four tumours involved the sphenoid bone. In three patients, the tumour extended to the ethmoid sinus and both cavernous sinuses. All lesions were isointense solid masses on T2-weighted images and showed avid enhancement, except for one lesion with a focal necrosis. All tumours were associated with adjacent dural thickening. Non-contrast CT showed highly attenuating masses and permeative bone destruction in the central skull base.

CONCLUSION

Lymphoma involving the central skull base in children is visualized as an isointense mass on T2-weighted MRI with marked contrast enhancement and adjacent dural thickening, and as a highly attenuating mass on noncontrast CT with permeative or erosive bone destruction patterns.

Primary B cell lymphoma of the sphenoid sinus: CT and MRI characteristics with correlation to perfusion and spectroscopic imaging features

Primary non-Hodgkin lymphoma (NHL) of the paranasal sinuses is a rare neoplasm that cannot be easily diagnosed and differentiated as its clinical, histological, and imaging features are similar to those of other inflammatory and tumorous diseases in their early stages. We evaluated the morphological and functional imaging characteristics of primary NHL of the sphenoid sinus using CT and MR imaging. Morphological CT and MR imaging as well as perfusion CT imaging and proton MR spectroscopy (PRESS technique, TE = 135) was performed in three patients with the histological diagnosis of highly malignant primary B cell lymphoma of the sphenoid sinus. In all patients an inhomogeneous contrast agent enhancement as well as bony erosion of the sphenoid sinus was identified in CT and MR sections. In one patient an infiltration of the adjacent dura was present. The mean blood flow of the lymphomas was 135 ml/min per 100 g tissue, the mean blood volume was 8.06 ml/min, while the mean transit time and the mean permeability surface area product values were 5.11 s and 26.53 ml/min per 100 g, respectively. The mean choline to creatine ratio in the proton MR spectroscopy was 5.7. Cross-sectional imaging findings are not sufficient to establish the diagnosis of a primary NHL in the sphenoid sinus. Physiologic imaging offers valuable information that may be characteristic of the tumor. Future studies may lead to a safe differentiation of the lymphomas from other pathologic entities based on the combination of morphological and functional imaging.