Lymphoplasmacyte-rich meningioma with atypical cystic-solid feature: A case report

Abstract

Background: Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of meningioma and is classified as grade I (benign) tumor. It is characterized by abundant infiltrates of lymphocytes and plasma cells. Here, we report an extremely rare case of LPRM with an atypical imaging finding of multiple cysts around a solid mass.

Case summary: The patient was a 36-year-old man with intermittent headache, dizziness, and vomiting for 2 years. Computed tomography and magnetic resonance imaging presented a cystic solid mass in the right frontal lobe with heavy peritumoral edema and obvious contrast enhancement. The patient was treated with right frontotemporal craniotomy, and gross total resection of the tumor was achieved without adjuvant therapy. There was no clinical or neuroradiological evidence of recurrent or residual tumor for 3 years after initial surgery.

Conclusion: LPRM is one of the rarest variants of meningioma. Although, the mass of this case had common features, multiple cysts with nonuniform size and thin wall around the solid part are uncommon imaging finding, increasing the rate of misdiagnosis. The definitive diagnosis of LPRM relies on histopathological findings.

Keywords: Case report; Computed tomography; Lymphocyte; Lymphoplasmacyte-rich meningioma; Magnetic resonance imaging; Plasmacyte.

Figure 1

Computed tomography findings. A: Non-contrast computed tomography showed an irregular hypodense and isodense mixed mass in the right frontal lobe (long arrow), with obvious peritumoral edema around it; B: Bone window showed that the right frontal bone became thin (short arrow).

Figure 2

Magnetic resonance imaging findings. Magnetic resonance imaging showed an irregular, cystic solid mass with surrounding edema in the right frontal lobe. The solid part was approximately 4 cm × 3 cm × 2.5 cm. A: The solid part and cystic wall of the mass exhibited slight hyperintensity on T1-weighted imaging (T1WI); B: Hypointensity on T2-weighted imaging; C: Isointensity on fluid attenuated inversion recovery; D: Diffusion-weighted imaging. Several spots of hypointensity on T1WI and hyperintensity on T2-weighted imaging; E-H: Gadolinium-enhanced T1WI showed that the solid part and cystic wall (long arrow) were strongly enhanced, with dural attachment and dural tail sign (short arrow).

Figure 3

Microscopic characteristics of the tumor tissue. A: Hematoxylin and eosin staining (100 ×) showed multiple nests of meningothelial cells and syncytial tumor cells arranged in sheets or weaving. The size was consistent, and nuclear heterotypes were not obvious. Tumor stroma with massive lymphocytic and plasmocytic infiltration, and lymphoid follicular formation was identified in a local focus; B: Immunohistochemical staining revealed that the tumor cells were positive for epithelial membrane antigen (200 ×); C: Vimentin (200 ×); D: T lymphocytes were positive for CD3 (100 ×); E: B lymphocytes were positive for CD20 (100 ×); F: Plasmocytes were positive for CD38 (100 ×).