A case of rapid-growing anaplastic meningiomas

Abstract

Meningiomas are tumours originating from the leptomeningeal covering of the brain and spinal cord and are generally benign and slow growing. Rarely, they show malignant anaplastic characteristics with a high recurrence rate. A number of factors have been reported to predict this high recurrence. Such factors are histopathological ones, such as necrosis and hypercellularity, the World Health Organization (WHO) grade, mitotic index, positivity of proliferation markers (Ki-67 or MIB-1), clinical parameters such as age, gender, localisation, cytogenetic factors and radiation treatment. The present case reports a patient with a giant meningioma over the right frontal lobe who had almost all possible negative prognostic parameters and showed an explosive multifocal recurrence in a timespan of about 5 months.

BACKGROUND

Menigiomas are mostly benign tumours.¹ There are three grades of meningiomas: World Health Organization (WHO) grade I meningiomas have a small recurrence rate, grade II (atypical) meningiomas have a higher one and grade III meningiomas have a recurrence rate which is approximately 50% to 75%.² There are different predictive factors described in a number of studies and Kim et al have shown the relative recurrence rate for every one of these known factors.¹

There are an appreciable number of publications dealing with anaplastic meningiomas. Nevertheless, we are presenting a very illustrative case of a patient with a giant anaplastic meningioma that was treated with complete surgical removal and radiation treatment and massively recurred after only 8 months, although the direct postoperative and 4-month MRI scans confirmed total tumour removal. Only 5 months after the last “clean” MRI of the brain, meningiomas of different sizes grew all over the brain as well as in the surgically treated area. The patient had almost every negative prognostic parameter known in the literature. We stress how malignant anaplastic meningiomas can actually be.

CASE PRESENTATION

We report the case of a 71-year-old man who came to our neurosurgical outpatient clinic because of a rapid-growing tumourous mass in his right forehead. There were no neurological deficits. MRI showed a highly vascularised tumour (fig 1A) which it was decided to remove surgically.

Figure 1.

Anaplastic meningioma on the right frontal lobe. A. Initial MRI showing a giant tumour over the right frontal lobe. B. Postoperative MRI showing the complete tumour removal and removal of the invaded cranium. Axial, sagittal and coronal planes.

INVESTIGATIONS

Biopsy of surgical specimens led to a diagnosis of anaplastic meningioma (WHO grade III).

There was a great number of hypercellular areas and small cell formation, >10% necrotic areas, proliferation index (MIB-1) of 60%, mitotic index of >20/10 high power fields and macronucleoli.

DIFFERENTIAL DIAGNOSIS

Because of the vascularisation and very fast growth, haemangiopericytoma was considered in the differential diagnosis.

TREATMENT

Surgery with complete removal of the tumour was performed. The invaded cranium was also removed, as well as the invaded dura (Simpson I resection). After surgery and verification of the diagnosis, radiation treatment with a cumulative dose of 59.4 Gy (1.8 Gy partial dose) followed. The radiation treatment lasted 3 months.

OUTCOME AND FOLLOW-UP

At 1 month after radiation treatment an MRI of the brain was performed and no sign of recurrence could be seen (fig 1B). At 5 months thereafter the patient noticed multiple bumps over the surgically treated (craniectomised) area. A second MRI revealed a recurrence of the meningioma and, at this time, multiple meningiomas were spread all over the brain (convexities, temporal areas) (figs 2 and 3).

Figure 2.

Explosive tumour growth in multiple sites: 6 months after brain radiation and a “clean” MRI, this new MRI shows multiple tumours all over the brain.

Figure 3.

Overview of the brain after surgery and 6 months after radiation. The tumours (bitemporal, left convexity) did not exist immediately after radiation (A), and developed in the short period of a few months (B). C. Photograph of the patient’s head showing the tumours growing under the skin.

DISCUSSION

Kim et al summarised the risk of recurrence of meningiomas according to different factors.¹ The factors described by Kim et al and the data of our reported patient are shown in table 1. Other studies report meningioma induction after radiation treatment identifying radiation as a cause for their occurrence.^3,4 Jääskeläinen et al⁵ studied 936 meningiomas and found that only 1% of these were anaplastic (WHO grade III). At 5 years after complete removal the recurrence rate for the anaplastic meningiomas is 78%, whereas benign meningiomas recur in only 3% of cases. A total of 80% of anaplastic meningiomas recur in spite of radiation treatment. The median time of recurrence for anaplastic meningiomas is 3.5 years. In our case the tumour recurred after 8 months and new tumours developed in this period of time. Whether the occurrence of this new tumour was induced after radiation or not cannot be easily proven, for there are a number of studies showing correlation between meningiomas and radiation. It is rather more likely that the multifocal recurrence had to do with the nature of the malignant meningioma, because it is not usually observed to this extent in patients with subtotal removal of WHO I or II meningiomas that are also in their majority of cases followed by radiation treatment. Radiation treatment in childhood leukaemia, for example, shows the development of meningiomas after a long latency of 13–34 years (mean 25 years).⁶ Multiple-site meningiomas have also been reported.^6,7 Another article has reported on radiation-induced meningioma in a patient with acute lymphocytic leukaemia. The authors report that radiation-induced meningiomas are unlike primary meningiomas in that they are more diffuse, multiple in number and may undergo malignant degeneration.⁸ However, in the studies correlating radiation with meningiomas^4,7–9 the induction of tumours is a long-term radiation effect. From this point of view the tumours in our patient developed only a few months after radiation.

Table 1.

Negative prognostic factors given in the literature¹ compared to the presented case

Parameter	Relative recurrence risk (%)	Present case (absolute numbers)
Clinical parameters:
Age >65 years	19	71 years
Gender (f/m)	11/19	Male
Convexity/other location	12/9	Convexity
Total/subtotal	12/47	Total with local infiltration
Local infiltration	28
Histopathological parameters:
Hypercellularity	26	Positive
Small cell formation	25	Positive
Macronucleoli	32	Positive
Necrosis	33	>10% of HPF
Brain invasion/non-invasion	28/10	Brain invasion
WHO grade:
II/I	18/9
III/I and II	75/11	Grade III
Mitotic index
>4/10 HPF	38
>20/10 HPF	83	>20/10 HPF
Ki-67:
>8%	29
>12%	42	>60%
Cytogenetic factors	20–45	Not evaluated

HPF, high power fields; WHO, World Health Organization.

LEARNING POINTS

• Meningiomas of the brain are not always benign. In 1% of cases they can be highly malignant and non-treatable.

• Radiation can induce multiple-site meningiomas, which can be more malignant than primary ones. After radiation treatment, especially in children, brain MRI scans over long time intervals could be of clinical relevance.

• There are prognostic factors in meningiomas that are helpful in estimating the prognostic surgical value.