Meningioma with extensive noncalcifying collagenous whorls and glial fibrillary acidic protein expression: new variant of meningioma diagnosed by smear preparation

Whorling-Sclerosing Variant Meningioma of the Spine: Surgical Management and Outcome of an Extremely Rare Case

STUDY DESIGN

Case report OBJECTIVE.: To report surgical resection of multiple ventral cervical and thoracic lesion being diagnosed as whorling-sclerosing variant meningioma (WSM) and subsequent stabilization of cervicothoracic spine.

SUMMARY OF BACKGROUND DATA

WSM is a rare histopathology variant of meningioma which is mostly reported in brain and only one case of cervical spine WSM has been reported. Because of the rarity of WSM, there is a paucity of information regarding the clinical, radiological, and histopathologic characteristics.

METHODS

A 57-year-old lady presented with progressive quadriparesis and myelopathy since 10 days. The spine magnetic resonance imaging (MRI) revealed multiple ventral cervical and thoracic lesions which were hypointense in T2-weighted images with heterogeneous and scant enhancement with gadolinium. The patient underwent anterior cervical corpectomy and gross total resection of the lesion along with 360° fixation in the first stage. The thoracic lesions were also resected totally through laminectomy and right lateral extracavitary approach followed by pedicular screw fixation.

RESULTS

The patient improved muscle powers and spasticity and is not independent (Frankel D). The histopathology examination revealed hypocellular lobulated sclerotic mass with whorling pattern of growth in the sclerotic part suggestive of WSM. Immunohistochemical evaluation demonstrated negative staining for epithelial membrane antigen, cytokeratin, Olig-2 and S-100 and immunoactivity for progesterone receptor (PR) and glial fibrillary acidic protein in the tumoral cells located at the periphery. Ki-67 indexing was low.

CONCLUSION

The spine multiple WSM is an extremely rare condition, which has a malignant behavior and it seems that it is spread by cerebrospinal fluid seeding. Surgical removal is hard and requires experience and appropriate equipment.

LEVEL OF EVIDENCE

4.

Sclerosing Meningioma : Radiological and Clinical Characteristics of 21 Cases

Objective

A rare subtype of meningioma, sclerosing meningioma is not included in the current World Health Organization classification of meningiomas and is classified into the category of other morphological variation subtypes. Sclerosing meningioma is often misdiagnosed to other non-benign meningioma or malignant neoplasm, so it is important to diagnose sclerosing type correctly. We analyzed the radiological and clinical characteristics of a series of sclerosing meningiomas.

Methods

Twenty-one patients who underwent surgery in one institute with a histopathologically proven sclerosing meningioma were included from 2006 to 2014. Eighteen tumors were diagnosed as a pure sclerosing-type meningioma, and 3 as mixed type. Magnetic resonance image was taken for all patients including contrast enhancement image. Computed tomography (CT) scan was taken for 16 patients. One neuroradiologist and 1 neurosurgeon reviewed all images retrospectively.

Results

In the all 16 patients with preoperative CT images, higher attenuation was observed in the meningioma than in the brain parenchyma, and calcification was observed in 11 (69%). In 15 of the 21 patients (71%), a distinctive very low signal intensity appeared as a dark color in T2-weighted images. Nine of these 15 tumors (60%) exhibited heterogeneous enhancement, and 6 (40%) exhibited homogeneous enhancement that was unlike the homogeneous enhancing pattern shown by conventional meningiomas. Ten patients had a clear tumor margin without peritumoral edema.

Conclusion

Although these peculiar radiological characteristics are not unique to sclerosing meningioma, we believe that they are distinctive features that may be helpful for distinguishing sclerosing meningioma from other subtypes.

A rare case of intramedullary 'whorling-sclerosing' variant meningioma

A 52-year-old man with a seven-year history of progressive weakness, gait problems, and pain in his extremities presented with subacute worsening of his symptoms. Examination revealed weakness in all four extremities, increased tone, hyperreflexia, and sensory deficits. MRI of the cervical spine showed an area of signal abnormality and abnormal enhancement within the cervical cord at the C5–C6 level. The patient initially underwent biopsy followed a few days later by a debulking surgery. Postoperatively, the patient showed improvement in strength as well as ambulation. Intraoperatively, the lesion was confirmed to be intramedullary without any dural attachments. Histopathological examination revealed an extensively hyalinized tumor with sparse collections of cells that were immunopositive for both cytokeratin and GFAP, and immunonegative for EMA and progesterone receptor. This is an unusual pattern of expression, with cytokeratin immunopositivity suggesting a meningioma and GFAP immunopositivity suggesting a glioma. Considering the combination of extensive hyalinization with cytokeratin positivity the tumor was thought to be most consistent with a hyalinized meningioma with GFAP positivity. GFAP-positive meningiomas are rare, and these include the recently described ‘whorling-sclerosing’ variant. Only three cases of this tumor have been previously reported, all of which were intracranial. This is the first reported case of an intramedullary whorling-sclerosing meningioma.

Pathology and molecular genetics of meningioma: recent advances

Meningiomas are the most common intracranial primary neoplasm in adults. Although the spectrum of clinical and molecular genetic issues regarding meningiomas remains undefined, novel genetic alterations that are associated with tumor morphology, malignancy, or location have recently been discovered. This review focuses on recent advances in understanding of the heterogenous pathology of meningiomas, particularly on associations between the clinical, histological, etiological, epidemiological, and molecular genetical aspects of the neoplasm.

Sclerosing meningioma: immunohistochemical analysis of five cases

Sclerosing meningioma is a rare morphologic subtype of meningioma and may be mistaken for atypical or malignant meningioma and astrocytoma or schwannoma because of marked collagen deposits and a sparse population of cells with little resemblance to meningothelial cells. Authors describe the histopathologic and immunophenotypic features of five cases of sclerosing meningioma. Histologically, all the cases consisted of paucicellular collagenous tissue containing spindle cells with or without small foci of meningothelial cell proliferation. The morphology and immunohistochemical profile of the spindle cells were different from those of conventional meningothelial cells. The meningothelial cells showed a typical immunoreactivity of conventional meningiomas, while the spindle cells displayed a strong expression of vimentin. The Ki-67 labelling index was uniformly low in all cases, and none of cases expressed p53 protein. In summary, the recognition of meningothelial cells in massively sclerotic lesions is helpful for a correct diagnosis. In the cases with a total absence of meningothelial cells, however, the vague collagenous whorls are more diagnostic rather than immunohistochemistry. Considering association with clear cell meningioma, prospective and retrospective long-term follow-up is necessary for deciding whether reminiscent clear cell meningiomas should be separated from sclerosing meningioma or not.