Arachnoids cysts (AC) are non-tumoral and congenital lesions and constitute 1% of all intracranial space occupying lesions [1]. Ninety percent of ACs is located in the supratentorial region and 10% are in the posterior fosse [2]. The middle cranial fosse is the most common place of the ACs (60%) other sites include seller region, cerebral convexity, and quadrigeminal plate. The clinical signs and symptoms of ACs are relegated with their size, anatomic location and influence on the cerebrospinal fluid (CSF). Symptomatic ACs is usually diagnosed in the first or second decades of life due to increased intracranial pressure, craniomegaly or developmental delay. The definition of meditational goiter (MG) generally refers to a stoma with location for at least 50% of its volume in substernal position [3]. MG is a rare disease that generally diagnosed incidentally, and up to 40% of MGs are asymptomatic [4]. They may cause compressive symptoms in the surrounding tissues if they are large enough.
Case ReportA sixtyeight year old right handed woman was admitted to our clinic with headache which increased for last six months and seizure complaintes. Physical examination of the patient's head, neck and abdomen were normal. Neurologic examination did not show any abnormalities. We check both the thyroid hormones and thyroid stimulation hormone levels routinely before operation and were normal. Computerized tomography (CT) and contrast enhanced magnetic resonance imaging (MRI) showed a 56x48x90 mm in size cytic lesion on the right occipital lobe of the brain which has very close relationship with the posterior pole of right lateral ventricle. The cyst did not enhanced after contrast media injection and reported as an AC. A right Cystoperitoneal shunting operation was planned. After entubation of the patient, a pillow was placed under the shoulders to provide extension to the neck.In a few minutes after positioning of the patient, a lump in 4x5 cm size appeared on the right anterolateral side of the neck, and the anesthesiologist said the patient had difficulty in ventilation. Ultra son graphic examination was performed in operating room and showed a nodule 43x66x78 mm in size which moved from right lobe of thyroid to the retrosternal region. The operation has cancelled, and position changed to normal which caused disappearing of the lesion. The patient extubated and detailed endocrinology and radiologic examination were planned. The patient consulted by general surgeon and they decided to operate the patient before cysto-peritoneal shunt operation.