Giant intraventricular and scalp mass lesions

A 50-year-old female patient presented to our hospital with a complaint of swelling and headache on the back of her head. It was determined from the patient's history that she had undergone surgery to remove the brain tumour eight years earlier, but the records could not be reached.

Figure 1A-B: Coronal T2- (A) and T1-weighted (B) magnetic resonance images show solid masses with flow void areas of similar intensity with grey matter in the scalp (white asterisk) and lateral ventricle (black asterisk). The defects of craniotomy in the skull of the patient are remarkable (arrows).

Figure 2A-B: Coronal (A) and axial (B) post-contrast T1-weighted magnetic resonance images show heterogeneous and intense enhancement in both intraventricular (black asterisk) and scalp (white asterisk) masses.

Hemangiopericytoma originates from contractile smooth muscle cells called pericytes located on the outer surface of the capillary artery and post-capillary venules. It is most commonly seen in middle-aged women. They are usually located in the lower extremities, pelvis, retroperitoneum, trunk, and upper extremities. Intracranial hemangiopericytomas are rare, accounting for less than 1% of all intracranial neoplasms. However, they can be aggressive, and recurrence is common [1].

Patients most often present to the hospital due to a slowly growing painless mass, which can also cause additional symptoms depending on location. Various paraneoplastic syndromes, such as hypoglycemia, hypophosphatemic osteoma, and hypertrophic pulmonary osteoarthropathy can also accompany the tumour [2].

Hemangiopericytomas are usually seen as solitary supratentorial masses. They are intense vascular lesions. They tend to erode the adjacent bone. The posterior occipital region is another common site. Computed tomography (CT) images show significant erosion of the adjacent bone and significant enhancement in post-contrast series. It differs from meningioma due to the absence of calcification within the tumour and hyperostosis of the adjacent bone. MRI shows the masses as isointense with grey matter on T1- and T2-weighted images, containing flow void areas. It demonstrates significant and heterogeneous enhancement on post-contrast images [3]. The MR spectroscopy findings of hemangiopericytoma differs from that of meningioma with the presence of a myoinositol peak and the absence of an alanine peak [4].

Local wide excision is the first treatment modality in hemangiopericytomas. There is no consensus on the effectiveness of postoperative radiotherapy and chemotherapy. Hemangiopericytomas are considered resistant to radiotherapy. Radiotherapy can be used as an adjuvant in the presence of a recurrent tumour and a histologically high-grade tumour if the lesion cannot be completely removed. Chemotherapy can be used in the presence of distant metastases [5].

In conclusion, hemangiopericytomas are rare, but a radiologically accurate diagnosis is important because it will determine the management of the disease.

Written informed patient consent for publication has been obtained.