Pineal region tumors represent less than 1% and 3-8% of brain tumors in adults and children respectively. There is a wide range of pineal masses, with the majority being germ cell and pineal parenchymal tumors. Magnetic resonance imaging (MRI) is the modality of choice for the assessment of pineal masses. It is considered as the gold standard for the evaluation of the central nervous system. MRI has the ability to produce very detailed images of the brain anatomy and is used to distinguish true pineal masses from parapineal with invasion of the gland. Specific MRI findings are helpful to the differential diagnosis of pineal tumors and the distinction between benign from malignant tumors. Pineal neoplasms may seed the subarachnoid space resulting in the development of intradural extramedullary metastases, known as drop metastases. MRI is the most sensitive method for the assessment of the spinal cord, meninges and nerve roots and the differentiation of the spinal lesions into intra/extra medullary and extradural. Because of its high sensitivity and the advances of the method, drop metastases can be easily diagnosed at an earlier stage than in the past, contributing to the selection of the appropriate treatment. Therefore, the entire neuroaxis should be investigated with MRI for the presence of intradural extramedullary lesions. The present study focuses on the main MR imaging characteristics of pineal masses and drop metastases with reference to the differential diagnosis. There is also a detailed approach to the MR protocol which should be obtained in order to evaluate the lesions.

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign myofibroblastic process. We present the case of a 17-year-old girl who underwent diagnostic work-up due to an enlargement of her left breast. She was submitted to ultrasounds and magnetic resonance imaging (MRI) which depicted a 14 cm lesion in her left breast. The patient was later operated and histology revealed PASH. Although PASH may range from 0.6–12 cm, a few lesions over 12 cm have been described, the largest being 20 cm. Large series present mammographic and ultrasonographic features of PASH in the literature, but little has been reported on the MR characteristics of PASH up to today. Signal on the T1-weighted image (T1WI) and T2-weighted image (T2WI) may vary. Curves generated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies are mainly type I or less frequently type II. There are no reports about diffusion-weighted imaging and corresponding apparent diffusion coefficient (ADC) values for PASH in the literature. ADC values in our case lie within the range of values reported for other benign breast lesions. The presence of slit-like spaces within the lesion on MR imaging along with DCE-MRI type I curve and ADC values consistent with a benign lesion may favour the diagnosis of PASH. Tissue biopsy is necessary, however for the final diagnosis. This case report will further contribute to the understanding of MR imaging features of PASH, especially in cases where mammography is not indicated.

Myositis is a rare bacterial muscle infection. Involvement of the piriformis muscle has been rarely reported in the literature. In this report we describe a case of piriformis myositis due to Brucella melitensis, which to the best of our knowledge is the first such case presented in the literature.

Brucellar epidural abscess is rare but potentially fatal medical entity and very few cases have been reported so far. Whilst in developed countries, cases of brucellar spondylitis and epidural abscess are unusual, since brucellosis has practically been eradicated in animals, in Greece it is one of the most frequent zoonosis. By reporting this case report we want to stress out the importance of early diagnosis and management and also that physicians should keep an open mind and high index of suspicion especially in regions where brucellosis is endemic or when their patients have traveled to these areas and have consumed unpasteurized dairy products.