Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report

Spontaneous regression of a posterior fossa meningioma: A case report

Background:

Since most incidentally discovered meningiomas grow or remain unchanged, spontaneous regression is extremely rare. Here, we report a case of posterior fossa meningioma showing spontaneous regression.

Case Description:

A 55-year-old female was referred to our hospital because she was diagnosed with a left posterior fossa meningioma (diameter: 1.6 cm) during a brain check-up. The patient was followed up on periodic magnetic resonance imaging studies. Tumor size remained almost unchanged for 2 years but then began to regress. Twelve years after the initial examination, the tumor diameter idiopathically decreased from 1.6 cm to 1.1 cm while the tumor volume decreased from 2.3 cm³ to 0.5 cm³ (about 1/4^th the original size). Postmenopausal hormonal imbalances may have been associated with the observed spontaneous regression.

Conclusion:

Understanding the natural history of meningiomas is essential for a better selection of treatment approaches or appropriate follow-up. This case may provide new insights into the progression of meningiomas.

Primary Heterotopic Meningioma of Nasal Cavity: Case Report and Literature Review

Primary heterotopic meningiomas are lesions that are not associated with a cranial nerve foramen, vertebral canal, or intracranial structure. The most common histopathological subtype is meningeal epithelioma. In clinical practice, primary heterotopic nasal meningioma occurs relatively rarely, and its most common pathological type is psammomatous meningioma, whereas nasal fibrous meningioma is infrequent. In our case, a 31-year-old male patient was admitted to the hospital with "progressive nasal obstruction on the right side for half a year." Computed tomography examination of the paranasal sinuses revealed a polyploid mass in the right nasal cavity. The patient underwent surgical resection of the mass under nasal endoscopy. Histopathological examination confirmed that the mass was an ectopic meningioma of the nasal cavity. The patient was regularly followed up for 2 years without recurrence of the tumor. Primary heterotopic fibrous meningioma of the nasal cavity is clinically rare but should be considered as a differential diagnosis for hemangioma of the nasal cavity, inverted papilloma, and nasal polyp. The final diagnosis is based on pathology and immunohistochemistry analysis results.

Hormonal therapy for fertility and huge meningioma: a purely random association?

Sexual hormones have been related to the growth of meningiomas, also due to the almost constant expression of hormonal receptors by tumoral cells. A case of a woman with previous history of multiple treatment for infertility, harboring a huge meningioma is here described. The tumor was surgically resected and the immunohistochemical examination revealed a high expression of progesterone receptors on tumoral cells surface. A putative role of past progesterone administration in the growth of meningioma has been hypothesized. Particular caution should be paid whenever adopting sexual hormonal therapy, especially for fertility. A radiological examination (ideally MRI) could be advised before starting therapy, in order to rule out any intracranial meningioma.

Boron neutron capture therapy for recurrent malignant meningioma. Case report

Malignant meningioma is a rare brain tumor with a high risk of recurrence. If this tumor recurs after complete resection and adjuvant radiotherapy, there is no optimal treatment to control it. The authors report the first case of recurrent malignant meningioma treated using boron neutron capture therapy (BNCT). This 25-year-old pregnant woman presented with a large frontal tumor. After her baby was born, she underwent gross-total resection of the tumor. A second resection and three Gamma Knife surgeries could not control progression of the enhancing mass; therefore, the authors applied BNCT based on their experience with it in the treatment of malignant gliomas. The minimum tumor dose and maximum brain tissue dose were estimated as 39.7 Gy-Eq and less than 9.0 Gy-Eq, respectively. Before BNCT the patient was mobile by wheelchair only, whereas 1 week after therapy she was able to walk. Twenty-two weeks later she underwent a second BNCT for tumor regrowth on the contralateral side, and the lesion was subsequently reduced. The tumor volume was markedly decreased from 65.6 cm3 at the time of the first BNCT to 31.8 cm3 at 26 weeks thereafter. The treatment of recurrent malignant meningioma is difficult and has been discouraging thus far. Data in the present case indicate that BNCT may be a promising treatment option for this challenging tumor.

Female predominance in meningiomas can not be explained by differences in progesterone, estrogen, or androgen receptor expression

The female predominance in meningioma incidence and association between meningioma and breast cancer suggest that growth of meningiomas is hormone-dependent. There are several discrepancies in literature about the proliferative effect of sex hormones on meningiomas. This study aims to evaluate the hormone receptor status of meningiomas and assess its relation to age, sex, histological grade, recurrence, and proliferation activity. The material was based on consecutive patients operated for meningioma at Tampere University Hospital in 1989-1999. The occurrence of progesterone, estrogen and androgen receptor in patients with primary and recurrent meningiomas was studied immunohistochemically by using specific monoclonal antibodies. Hormonal status was determined in 510 tumor samples. 443 samples were from primary meningiomas and 67 from recurrent tumors. Of the samples, 455 were benign (WHO grade I), 49 atypical (grade II), and 6 malignant (grade III). Of the primary tumor samples, 88% were progesterone receptor positive, 40% were positive for estrogen and 39% for androgen receptors. Grade I meningiomas had significantly higher incidence for estrogen and androgen receptors than higher grade meningiomas. Estrogen positive tumor samples had significantly higher proliferation index than estrogen negative samples. No difference in expression of sex hormone receptors was observed by sexes or age group. Estrogen and androgen receptors may have more influence on the pathogenesis of meningiomas than earlier thought. The higher incidence of meningiomas in women can not be explained by differences of sex hormone receptor expression.

Meningiomas: Updating Basic Science, Management, and Outcome

BACKGROUND

Meningiomas are biologically complex and clinically and surgically challenging. These features, combined with the rewarding potential for cure, make them of great interest to neurologists, neurosurgeons, and neuroscientists alike.

REVIEW SUMMARY

Initially, we review the clinical context of meningiomas, particularly recent changes in histopathological classification, diagnosis, and neuroimaging. Secondly, the underlying basic science as it has evolved over the last decades is summarized. The status of areas recently of intense interest, such as steroid hormone receptors and oncogenic viruses is described. Additionally, emerging areas of great promise, such as cytogenetics and molecular biology are presented. Lastly, we describe recent advances in management. In particular, skull-base surgery, image-guided surgery, and advances in radiotherapy are emphasized. The possible impact of basic research on management and outcome is also outlined.

CONCLUSIONS

Although usually benign and amenable to cure, meningiomas still present significant diagnostic and treatment challenges. Advances in basic science, surgery, and adjuvant therapy are widening the potential for safe, effective, evidence-based management leading to even better outcomes

Gene therapy for meningioma: improved gene delivery with targeted adenoviruses

OBJECT

Due to their surgical inaccessibility or aggressive behavior, some meningiomas cannot be cured with current treatment strategies. Gene therapy is an emerging strategy for the treatment of brain tumors, which the authors investigated to determine whether adenoviruses could be used for gene transfer in meningioma cells.

METHODS

The presence of the high-affinity Coxsackievirus and adenovirus receptor (CAR) for adenovirus type 5, as well as endothelial growth factor receptor (EGFR) and alpha, integrins (ITGAVs), were analyzed in primary tumors by using immunohistochemical studies and in primary meningioma cell cultures by using fluorescence-activated cell sorting. Targeting of adenoviruses to EGFR was achieved using bispecific antibodies, whereas targeting of adenoviruses to the ITGAVs was accomplished by insertion of an RGD (arginine-glycine-aspartic acid) motif in the adenovirus fiber H1 loop. Gene transfer efficiency of untargeted and targeted vectors was compared in primary cell cultures and in spheroids derived from patients' resected tumor material. The presence of CARs was observed in all tumors and in all but one of the derived primary meningioma cells. The higher expression of EGFRs and ITGAVs indicated that these receptors could be used as alternative targets to redirect the adenoviruses. Redirection of adenoviruses to the EGFRs or integrins enhanced gene transfer threefold (range two-sevenfold) for EGFRs in primary meningioma cells and ninefold (range three-23-fold) for integrins (p = 0.002, analysis of variance). The effect of adenovirus targeting was confirmed in spheroids composed of primary meningioma cells.

CONCLUSIONS

Gene transfer with adenoviruses targeted to tumor-specific receptors is very effective in primary meningioma cells and spheroids. These vectors are promising agents for gene therapy of meningiomas.