Lipomatous meningioma: report of 2 cases and review of the literature

BACKGROUND: Lipomatous meningioma is a rare but, most of the time, benign tumor. Its pathogenesis is still debated: it is usually considered to be part of the metaplastic meningioma, but several authors recently suggested that fat accumulation inside the tumor was related to metabolic disorders of the meningothelial cells. CASES DESCRIPTION: We report 2 cases of lipomatous meningioma. Both patients were women older than 60 years. One patient suffered from headache and seizures, the other one presented with behavioral disturbance. Radiological features depended on the amount of fat accumulation within the tumor. Surgical treatment allowed complete resection in both cases without any complications. Both meningiomas were of transitional-type and were apparently composed of 2 populations of cells: meningothelial cells and lipid-laden cells resembling mature adipocytes. Immunohistochemical study showed that lipid-laden cells expressed EMA, CD99, and progesteron receptor, favoring a meningothelial differentiation rather than an adipocytic lineage. CONCLUSION: Our study strongly suggests that lipomatous meningioma results from an accumulation of lipid inside meningothelial cells rather than a true metaplasia.     

Early malignant transformation of a petroclival meningothelial meningioma

Although some authors have reported the malignant transformation of meningiomas, there has been no previous report describing that a meningothelial meningioma transformed into an atypical meningioma within 1 year. This report documents a 57-year-old woman who presented with right hearing disturbance. Magnetic resonance imaging revealed a right petroclival meningioma. The tumor was subtotally removed and was diagnosed to be a meningothelial meningioma. Seven months after surgery, a recurrence of the tumor was confirmed. The diagnosis of this recurrent tumor was an atypical meningioma. The MIB-1 index and the percent of p53 protein-positive cells in the primary tumor were 4.6% and 35.4%, respectively, whereas those of the recurrent tumor were 34.7% and 33.1%, respectively. A chromosomal DNA copy number loss was observed on 1p, 6q, 10, 14q, and −22q detected in both the primary and the recurrent tumors. These results suggest that the present case had a potentially malignant tumor in the early stage, although it had the histological features of benign meningiomas. An evaluation of the MIB-1 index, as well as the expression of p53 and chromosomal aberrations, may be useful for predicting the malignant transformation of meningiomas.     

Meningothelial hamartoma of the scalp: two case reports and literature review

Meningothelial hamartomas are rare congenital scalp lesions composed of an admixture of cells including the meningothelial cell type. Histologically they are characterized as lesions with proliferative connective tissue, epitheloid cells forming interanastamosing vascular channels, and meningothelial elements. Lopez first described these lesions in 1974 and since that time a total of 32 cases have been reported [3]. In previous reports, they have been referred to as hamartomas with ectopic meningothelial elements, sequestered or rudimentary meningocele, and ectopic meningioma [1, 3, 5]. Two additional cases of meningothelial hamartomas are discussed as to their clinical presentation, work up, pathological findings at excision, and outcome. A persistent connection with the central nervous system remains a primary concern and mandates adequate preoperative testing to exclude this possibility. Correspondence to: L.C. Argenta     

Molecular alterations in the neurofibromatosis type 2 gene and its protein rarely occurring in meningothelial meningiomas

OBJECT: The neurofibromatosis Type 2 (NF2) gene is the only tumor suppressor gene that has been clearly implicated in the development of benign meningiomas. Interestingly, previous data obtained by the authors indicate that reduced NF2 protein expression seldom occurs in meningothelial meningiomas, the most common histological type of meningioma. The goal of the current study was to explore further the hypothesis of NF2 gene-independent tumorigenesis of meningothelial meningiomas. METHODS: The authors performed a mutational analysis of all 17 exons of the NF2 gene by using single-stranded conformational polymorphism (SSCP). In addition, expression levels of the NF2 protein and mu-calpain, a protease suggested to inactivate the NF2 protein, were determined by immunoblotting analysis of 27 meningiomas (20 meningothelial and seven nonmeningothelial). Mutations of the NF2 gene were found in only one (5%) of 20 meningothelial meningiomas and three (43%) of seven nonmeningothelial tumors (Fisher's exact test, p = 0.042). The levels of NF2 protein were severely reduced in six (28.5%) of 21 meningothelial meningiomas, in contrast to six (86%) of seven nonmeningothelial meningiomas (Fisher's exact test, p = 0.023). Activation of IL-calpain did not correlate with the status of NF2 protein expression in the meningiomas analyzed, demonstrating that mu-calpain activation does not account for the loss of NF2 protein in meningiomas with apparently normal NF2 genes. CONCLUSIONS: These results clearly demonstrate that NF2 gene mutations and decreased NF2 protein expression rarely occur in meningothelial meningiomas compared with other histological types of meningiomas. The clinical behavior of meningothelial meningiomas, however, is similar to that of other benign meningiomas. It is likely, therefore, that the tumorigenesis of meningothelial meningiomas is the result of deleterious alterations of genes that have final phenotypical effects similar to inactivation of the NF2 gene.     

Pulmonary meningioma. Immunohistochemical and ultrastructural features

Two cases of solitary primary pulmonary tumors showing the immunohistochemical and ultrastructural features of meningothelial meningiomas are presented. The benign clinical and radiologic course, the negative computed tomography scan of the brain (case 1), and negative neuropathologic investigation (case 2) support the diagnosis of a primary pulmonary meningioma rather than a metastazing malignant intracranial meningioma. Negative neuroendocrine markers (neuron-specific enolase, chromogranin, bombesin) and the lack of neurosecretory granules by electron microscopy confirm the diagnosis of this rare pulmonary tumor.     

Psammomatoid ossifying fibromas: immunohistochemical analysis and differential diagnosis with psammomatous meningiomas of craniofacial bones.

OBJECTIVE: To clarify the role of immunohistochemistry in the diagnosis of psammomatoid ossifying fibroma (PSOF), conventional cemento-ossifying fibroma (COF), and psammomatous meningioma (PM) of the craniofacial skeleton. STUDY DESIGN: The histology and immunohistochemistry of 4 PSOFs, 6 COFs, and 7 PMs was studied. Antibodies included EMA, cytokeratins, smooth muscle actin (SMA), desmin, vimentin, CD34, CD10, S-100 protein, and glial fibrillary acidic protein (GFAP). RESULTS: All PSOFs showed multiple round ossicles homogeneously distributed within a fibroblastic stroma. Psammomatous meningiomas had meningothelial features. All tumors, except 1 COF, were positive for EMA. All of them expressed vimentin, and none showed cytokeratins. Staining for SMA and S-100 protein was variable. CD10 was positive in all cases except 2 meningiomas. CD34 and GFAP stained only 1 case of meningioma each. CONCLUSIONS: The diagnosis of PSOF should rest on histologic features. An incorrect diagnosis of meningioma based on the expression of EMA should be avoided.     

Growth dynamics of meningiomas in patients with multiple sclerosis treated with interferon: report of two cases

Summary. Summary.   Background: Although multiple sclerosis (MS) is a common disease of the central nervous system, the association of intraparenchymal tumour has been rarely reported and the potential relationship between intracranial meningioma and MS has not been seriously analysed. This report addresses the association of multiple sclerosis and intracranial meningioma and discusses the effect of interferon treatment on tumour progression.   Clinical Presentation: We report two cases with multiple sclerosis, who developed meningioma four and twenty years after the diagnosis of MS was made. Neither patient had a history of meningioma initially and both were being treated interferon when the meningioma was progressed.   Findings: Histological examination of two cases revealed meningothelial meningioma. The first patient's KI67 level was 2.5% and was positive for the progesterone and estrogen receptor. Chromosomal analysis showed some abnormalities. In the second case, mild atypical change by presence of nuclear enlargement and rare mitotic figures were noted and PCNA, KI67 levels were less than 2%.   Conclusions: We reported the association of multiple sclerosis and intracranial meningioma and observed the progression of the meningiomas during interferon treatment. Although, we cannot exclude the coincidence between the two diseases we discussed suspicious relationship between the interferon treatment and the tumour progression.     

Progesterone-receptor index in meningiomas: correlation with clinico-pathological parameters and review of the literature

For recurrent and untreatable meningiomas alternative therapies, such as anti-progesterone treatment, have been sought. However, the few clinical studies have not determined progesterone receptor (PgR) expression in most cases, and studies correlating quantitative PgR expression (PgR index) with clinico-pathological variables are scarce. The aim of our study was to assess the PgR indices in a consecutive series of meningiomas and correlate these values with clinico-pathological parameters. We analyzed immunohistochemically 82 consecutive meningioma specimens (73 primary and nine recurrent tumors) for PgR and Ki-67 antigen (MIB-1). The male/female ratio was 1:1.7, and median age at the time of surgery was 57 years (range 29–77 years). The series comprised 55 grade I (subtyped as 36 meningothelial, seven fibrous, nine transitional, two psammomatous, and one angiomatous), 23 grade II, and one grade III meningiomas. Nuclear immunostaining for PgR was positive in 56 meningioma specimens (71%). PgR index was 21.4±2.8% (mean ± SE; range 0–79%). Significantly higher expression was found in male patients in the age group <50 years than in those 60 years and in grade I meningothelial meningiomas than in fibrous and transitional subtypes. There was a trend to lower PgR indices in non-benign meningiomas. Cell proliferation rate (MIB-1 index) was 4.4±0.4% (mean ± SE; range 0.3–15.4%). Significantly higher MIB-1 indices were found in male than female patients,in recurrent than primary and in grade II than grade I meningiomas. We observed a trend to higher PgR indices in meningiomas with MIB-1 index <5%. In sum, the highest PgR index in our series was observed in patients under the age of 50 years with WHO grade I meningiomas of the meningothelial subtype and low cell proliferation indices. If hormonal therapy has a direct action on the PgR, these patients should respond best to anti-progesterone treatment. We conclude that PgR index is variable in meningioma, depending on clinical parameters and histopathological features. Stratification of anti-progesterone therapy trials on the basis of PgR index should be considered.     

Lipomatous meningioma: a clinicopathologic study of 18 cases with special reference to the issue of metaplasia

We report 18 cases of lipomatous meningioma occurring in patients aged 14 to 79, most being females (72%). Sixteen were supratentorial and 2 involved the spinal meninges. Follow-up ranged from 1 to 120 months. Fifteen patients were cured with surgery alone and 3 (17%) experienced a recurrence at 7, 8 and 24 months. Of these, one died with disease 4 years after resection of the primary lesion. Histologically, 12 tumors were meningothelial, 3 transitional, 2 showed myxoid stromal changes and 1 was microcystic. The 2 spinal tumors were atypical. The proportion of fatty cells ranged from 10 to 90%. These resembled mature adipocytes or less commonly lipoblasts. Xanthomatous meningothelial cells were also noted in 6 tumors (30%). Both conventional meningothelial as well as lipid-laden cells exhibited epithelial membrane antigen immunoreactivity. In addition, occasional cells resembling mature adipocytes showed reactivity for S-100 protein. Ultrastructurally, lipidization of neoplastic cells varied from intracytoplasmic lipid droplets to a single massive globule. Moreover, lipid-laden meningothelial cells featured interdigitating cell membranes and well-formed desmosomes. Lipid droplets were not membrane-bound. In that metaplasia denotes differentiation of one mature cell type to another, lipid accumulation in meningiomas cannot be considered true metaplasia since their lipid-laden cells retain the immunophenotype and ultrastructural features of meningothelium. We suggest that this distinctive subset of meningiomas be termed "lipidized meningiomas" rather than being included in the metaplastic category.     

Prediction of meningioma consistency using fractional anisotropy value measured by magnetic resonance imaging

OBJECT: Preoperative planning for meningiomas requires information about tumor consistency as well as location and size. In the present study the authors aimed to determine whether the fractional anisotropy (FA) value calculated on the basis of preoperative magnetic resonance (MR) diffusion tensor (DT) imaging could predict meningioma consistency. METHODS: In 29 patients with intracranial meningiomas, MR DT imaging was performed preoperatively, and the FA values of the tumors were calculated. Tumor consistency was intraoperatively determined as hard or soft, and the histological diagnosis of the tumor was established. RESULTS: Of the 29 tumors, 11 were classified as hard and 18 as soft. The FA values of fibroblastic meningiomas were significantly higher than those of meningothelial meningiomas (p = 0.002). The FA values of hard tumors were significantly higher than those of soft tumors (p = 0.0003). Logistic regression analysis demonstrated that the FA value was a significant independent predictor of tumor consistency (p = 0.007). CONCLUSIONS: The FA value calculated from preoperative MR DT imaging predicts meningioma consistency.     

A new subtype of meningioma

Three patients with small meningiomas presented with diffuse cerebral edema that was out of proportion to the size of tumors. All lesions were small and no brain invasion or unusual tumor vascularity or dural sinus involvement was noted in any of the three cases. Tumor material was subjected to conventional and immunohistochemical stains. All three tumors showed benign meningothelial components, prominent formation of hyaline inclusions (pseudopsammoma bodies), and striking vascular mural proliferation of small dark cells. All patients have remained asymptomatic without any evidence of tumor recurrence after a follow-up of 4-6 years. These tumors showed proliferation of pericytes in blood vessel walls and, therefore, represent a new subtype of meningothelial meningioma. In the study presented here, the location, size, histotype, and clinical findings that may influence the development of peritumoral brain edema are discussed in detail.     

Meningiomas of the Internal Auditory Canal: Two Case Reports

Meningiomas represent 3 to 12% of the tumors that involve the cerebellopontine angle and internal auditory canal (IAC). Intracanalicular meningiomas, however, are rare. Only 10 well-documented cases have been reported in the English literature. The differential diagnosis includes acoustic neuromas, facial nerve neuromas, hemangiomas, lipomas, and meningiomas. We report two new cases of intracanalicular meningioma. Both patients had unilateral tinnitus. In case 1, the patient also experienced sensorineural hearing loss with unilateral tinnitus. In case 1, the lesion appeared hyperintense on T1-weighted and hypointense on T2-weighted magnetic resonance images. In case 2, the patient had an enhancing lesion in the right IAC. The tumors were moderately cellular, and meningeal whorls and meningothelial inclusions were present. Immunohistochemical staining revealed the tumors to be positive for epithelial membrane antigen (EMA) and negative for S-100 protein. The radiologic findings that help distinguish a meningioma from other lesions are reviewed.     

Meningioma with meningioangiomatosis: a condition mimicking invasive meningiomas in children and young adults: report of two cases and review of the literature.

Meningioangiomatosis is a malformative meningovascular proliferation that occurs sporadically and in patients with neurofibromatosis type 2. Its histologic features of perivascular proliferation of elongated fibroblast and meningothelial cells trapping islands of gliotic cortex may be erroneously interpreted as invasion when an overlying meningioma is present. We report two cases of meningioangiomatosis associated with meningioma and review the literature on the subject for a total of six cases. The age of patients ranged from 9 months to 33 years. All cases were single lesions, and none had clinical evidence of neurofibromatosis type 2. Meningiomas in children have been regarded as having more aggressive behavior than their adult counterparts, with more frequent invasion of the underlying brain. The lack of correlation between brain invasion and recurrence observed in series of meningiomas in young patients may suggest that some of these lesions are meningioangiomatosis associated with meningioma rather than invasive meningiomas.     

Chordoid meningioma with polyclonal gammopathy. Case report

The authors present a case of chordoid meningioma in a 55-year-old woman who manifested headache and personality change. Magnetic resonance imaging of the brain and cerebral angiography demonstrated a mass in the right frontal lobe that resembled a typical convexity meningioma. However, the pathological diagnosis was chordoid meningioma, a rare subtype of this tumor that usually occurs in adolescence and is known to be associated with Castleman syndrome. A meningothelial meningiomatous pattern suggestive of a meningothelial origin was focally present, and cytokeratin-positive squamoid cells were noted in the tumor. The lesion lacked dense infiltration of lymphocytes and plasma cells. Polyclonal gammopathy was the only sign of Castleman syndrome and hypochromic microcytic anemia was absent in this case. Polyclonal gammopathy resolved completely 6 months after total removal of the mass.     

Unique infiltrating morphology of a meningioma-a case report

BACKGROUND: We report on the case of a patient with meningioma that was correctly identified through biopsy. CASE DESCRIPTION: A 69-year-old woman presented with slight headache and was then examined at our hospital. Neurologic and physical examinations found no abnormality. Magnetic resonance imaging demonstrated a well-enhanced huge, dural-based, and plaque-like mass extending throughout the parietooccipital convexity and the posterior fossa. Tumors pressed the adjacent brain cortex while extending along the Virchow-Robin space. A CT scan also showed hyperostosis on the parietooccipital bone. Angiography demonstrated a vascular blush that appeared to be of a tumor-like shape. A biopsy was performed to confirm the diagnosis. The histologic findings demonstrated meningothelial meningioma with infiltration into the Virchow-Robin space. CONCLUSIONS: Many radiographic patterns of meningioma have been reported, but the present case is quite rare. The radiographic and pathologic findings in our patient are discussed.     

Intraspinal clear cell meningioma: diagnosis and management: report of two cases

OBJECTIVE AND IMPORTANCE: Intraspinal clear cell meningioma is a rare morphological variant of meningioma. Only 13 case reports are found in the literature; therefore, no management strategy has been defined for this tumor type. This article describes two patients, reviews the literature, and proposes a treatment plan for clear cell meningioma. CLINICAL PRESENTATION: Two female patients, 22 months and 8 years of age, respectively, presented with localized neck and leg pain that limited their ability to walk. Magnetic resonance imaging revealed intradural tumors, a cervical intramedullary neoplasm in the younger patient, and a cauda equina tumor in the older child. INTERVENTION: Both patients underwent radical resection of their intradural tumor. Both tumors, however, recurred shortly (5 and 6 mo) after the initial operation. During the second operation, a radical removal was performed on each patient. Both patients received adjuvant radiotherapy. In addition, the younger patient developed posterior fossa metastasis 20 months after intraspinal surgery. CONCLUSION: Intraspinal clear cell meningiomas are very uncommon tumors. The clinical course in our two patients supports the reported 40% recurrence rate within 15 months. These tumors also can disseminate within the central nervous system. We recommend serial imaging studies every 3 months. For recurrent tumors, we recommend localized radiation therapy after reoperation.     

Extracranial meningioma in the vicinity of the temporal bone: a difficult preoperative diagnosis

BACKGROUND: Extracranial meningioma is a rare tumor, and most of the time only after histopathologic examination is diagnosis possible. CASE DESCRIPTION: A 40-year-old right-handed woman presented with progressive swelling over the right side of the forehead and temporal region associated with proptosis and visual loss. Incisional biopsy of the lesion was reported as spindle cell tumor. Computed tomography scan showed large enhancing predominantly extracranial lesion located in the right anterior frontotemporal region extending into the infratemporal fossa and a relatively thin sheet of tumor on the intracranial aspect of the thickened temporal. Intraoperative impression was malignant tumor involving the temporalis muscle, and a near total excision of the lesion was performed. Histopathologic features were suggestive of meningothelial meningioma arising from the temporal bone with predominant extracranial extension. CONCLUSION: Preoperative suspicion of a meningioma in this patient would have resulted in a more aggressive surgical approach as these lesions are relatively benign with indolent course.     

Arteriovenous malformation in meningothelial meningioma: case report

An unusual association of a meningioma and an arteriovenous malformation is reported. A 68-year-old man developed left homonymous hemianopsia, left hemiparesis, and gaze palsy. Magnetic resonance imaging showed a right occipital mass lesion containing multiple signal-void areas with tubular and honeycomb appearance, suggesting a marked vascular component. An angiogram showed abnormal vasculature in the mass supplied by the posterior cerebral artery and a dural arteriovenous malformation on the tentorium. Neuropathological examination after total removal of the mass revealed a meningothelial meningioma including major portions of an arteriovenous malformation that extended from the dura and leptomeninges, through the meningioma, and into the occipital lobe, where the tumor was located.