Lipoblastic meningioma: case report

Abstract

-We describe the case of a patient presenting a right parietal mass lesion with an heterogeneous aspect on computed tomography, with hyperdense contrast uptake areas and hypodense areas with fat density. The unusual aspect of the lesion prevented preoperative and intraoperative diagnosis. The final histopathological examination revealed a meningothelial neoplasia with adipose differentiation, characterizing a lipoblastic meningioma.KEY WORDS: lipoblastic meningioma, metaplastic meningioma, computed tomography. Meningioma lipoblástico: relato de casoRESUMO -Relatamos o caso de um paciente com uma lesão expansiva parietal direita, de aspecto heterogêneo na tomografia computadorizada, com áreas hipercaptantes após a administração de contraste e outras hipodensas sugestivas de gordura. O aspecto pouco habitual da lesão dificultou o diagnóstico pré e intra-operatório. O exame histopatológico definitivo foi de neoplasia meningotelial com diferenciação adiposa, caracterizando o meningioma lipoblástico. PALAVRAS-CHAVE: meningioma lipoblástico, meningioma metaplásico, tomografia computadorizada.Meningiomas are benign tumors of the central nervous system (CNS) originating from meningothelial cells which are located in the cranium and spinal canal. The incidence of the tumor is higher in females and increases with age 1 . Besides the clinical picture, imaging analyses are important for diagnosis, especially computed tomography (CT) and magnetic resonance imaging. Angiography is recommended in selected cases for surgical planning. CT is highly sensitive and specific for this type of tumor; however, in approximately 7 to 15% of cases the tumor presents an atypical aspect showing areas of hemorrhage, cysts or metaplastic alterations 2 . Meningiomas characteristically present histological variants, probably due to the complex embryogenesis of the meninges 3 . The formation of mesenchymal tissue inside these tumors such as bone, cartilage and fat is known to occur and is caused by metaplasia of its cells 1 . When these alterations are significant, they characterize a variant recognized as metaplastic meningioma in the WHO's classification of tumors of the CNS 4 . This is a rare variant that can be a diagnostic problem.We report a case that the final diagnosis was a lipoblastic meningioma. The report of this case is justified by the low incidence, diagnostic problems and therapeutic implications involved in these tumors.

DNA methylation profiling of a lipomatous meningioma: illustrative case

“…As mentioned previously, MRI and CT are the imaging modalities most often used to diagnose meningiomas and may even be used to identify certain lipomatous features. The attenuation coefficient of fat is -50 to -100 Hounsfield units (HU), permitting identification of lipid accumulation in tumors through hyperintense signals on T1W and T1W MRI or hypodense signals on CT. 23,36 However, a limitation of radiological imaging is that it may be difficult to distinguish lipomatous meningioma, or meningiomas in general, from other meningeal neoplasms such as solitary fibrous tumor (SFT)/hemangiopericytoma. This is an important distinction to make because SFTs are often malignant and have a greater likelihood of recurrence and metastasis compared with meningiomas, thus potentially requiring adjuvant radiotherapy or chemotherapy.…”

Visual Aura Secondary to Supratentorial Lipomatous Meningioma: A Rare Case Report

“…There are extra-axial lesions with dural tails which usually appear hypodense on CT scans due to the presence of fat [ 4 ], while on MRI the appearance is variable, presenting signal loss in the sequences with fat suppression. In case the adipose-tissue component is less predominant, the area is isointense in T1 and T2 sequences [ 5 ].…”

Lipomatous Meningioma: Clinical-Pathological Findings, Imaging Characterisation and Correlations of a Rare Type of Meningioma

“…described a single case of extra-axial meningioma on the orbit (35). The tumours showed a hypodensity signal on CT images, except in two cases (15,24), in which the lesion presented a hyperdense appearance with hypodense foci inside. Depending on the degree of fat component, meningiomas can be seen at CT images as hyperintense or hypointense with hyperintense foci in weighted T1, and hypo-isointense or hyperintense sequences in T2-weighted sequences.…”

“…The meningothelial cell with lipomatous metaplasia exhibited immunoreactivity to Epithelial Membrane Antigen (EMA) in 37 cases (5, 7-10, 15,16, 23-28, 33, 35, 36), and Vimentin in 15 cases (5, 9, 10, 15, 16, 23-26, 28, 35-37). Ten meningiomas presented progesterone receptor (5,6,15,27,33,34,37), nine meningiomas showed S100-Protein (11,24,26,27,35,36), three meningiomas presented CD99 (27,37), three meningioma showed Cytokeratin (8,11,34), and two cases resulted positive for CEA (8,11).…”

“…Lipomatous meningiomas show a hypodensity appearance because the fat tissue component has attenuation values between -50 and -100 Hounsfield Unit (H.U.) (24). When the adipose component is abundant, the lesions present a hyperintense signal in the T1 weighted images and T2 weighted with signal loss in the sequences with fat suppression.…”