Cerebellar Staphylococcal Abscess Accompanied with High Alfa-Fetoprotein in a Young Infant
A 2-month old male infant was presented to Children's Medical Center with enlarging head circumference, persistent vomiting, strabismus and developmental regression since two weeks ago. He was the second child born from non–sanguineous parents by cesarean section due to being repeated. His mother had a normal pregnancy without any antenatal risk factors. He found two and four centimeters head enlargement during the first and second month of life respectively. At admission his vital signs were stable. He lost social smile and neck righting during the next two weeks. He had weight loss in this period due to persistent vomiting and poor feeding. The child was irritable with wide and tense fontanel and a setting sun eye was present. The anterior fontanel was 4×5cm wide and the posterior fontanel measured around 1 cm. He had no prior history of fever, skin infection, ear discharge, trauma or bleeding tendency. He had not received antibiotics so far.\nExamination of central nervous system did not reveal any cranial nerve palsy or focal neurological deficit except for right side VIth nerve palsy and setting sun eye. Cardiovascular and respiratory system were within the normal limits except for small patent foramen ovale that was suggested to be managed conservatively. Hemoglobin was 12mg/100ml, white blood cells count were 12170/mm3 with 72% polymorphs, 1% band cells, and platelets 300,000/mm3. The sedimentation rate was 12 mm/h and C-reactive protein negative. Serum AFP was 629 µgr/l (reference range for this age: 0-20 µgram/l) and coagulation tests were normal. Cerebrospinal fluid (CSF) taken from ventricles was totally normal without high AFP level. Brain computed tomography scan revealed left cerebellar hypodense non-homogenous mass with severe hydrocephalus and periventricular edema. Magnetic resonance imaging (MRI) demonstrated a right cerebellar non homogenous mass, which occupied most part of the right cerebellum; it had cystic and solid components, isointense in T1-weighted and isointense to hyperintense in T2-weighted images with patchy ring enhancement. The lesion was herniated from the foramen magnum (, ). Chest X-ray and ultrasound of abdomen were completely normal.\nA cerebellar tumor, most probably teratoma, was thought to be the most likely diagnosis. External ventricular drainage was inserted and midline suboccipital craniotomy performed to remove the mass. There was no adhesion between pia mater and dura mater. A purple gray mass was evident from the surface, no cerebellar cortex was found at the surface. The mass had different solid and cystic non-suctionable components with moderate hemorrhage. Some cysts contained yellow odorless thick fluid that was sent for culture. The mass destroyed all right cerebellar tissue except for the superior surface and extended to the lateral wall of fourth ventricle. It was removed totally. Postoperative period was unremarkable except for partial right facial nerve paresis and occasional fever that recovered after one week with antibiotics. Staphylococcus aureus was cultured from the cyst material that was sensitive to vancomycin and amikacin. Treatment was carried out with vancomycin 60 mg/kg in four divided doses and amikacin 15 mg/kg in three divided doses for 4 weeks. Pathological examination revealed granulation tissue, fibrosis, inflammatory infiltration and gliosis without any tumor cells inside the specimen. HIV Elisa and assessment of cellular and humoral immunity to rule out immunodeficiency were normal. Serum AFP became unremarkable after three weeks. Follow-up MRI six months after surgery was free of disease.