Atypical teratoid rhabdoid tumor mimicking type II neurofibromatosis: A case report.

Brain magnetic resonance imaging (MRI) images of atypical teratoid rhabdoid tumor (ATRT) often present heterogeneous signals of various cells without remarkable features of the disease. We describe a unique case of atypical brain MRI images presenting as an type II neurofibromatosis and explore some diagnostic hints.A 1-year-and-7-month-old boy admitted to our department with a 7-day history of drowsiness and 2-day history of emesis, and his presenting complaint was repeated vomit. On physical examination, he had drowsiness, positive sun set sign, slow light reflection, high muscular tension of limbs and 55 cm head circumference. MRI presented masses of bilateral auditory nerve distribution area, the fourth ventricle and right frontal lobe, obstructive hydrocephalus, and amplified cisterna magna. Particularly, dumbbell shape tumor in left cerebellopontine angle area and the fourth ventricle showed iso- or hypo-intensity on T1-weighted image and mix-intensity on T2-weighted image with irregular frontier, obvious mutual high and low signal on T2-weighted image, and growing along cerebrospinal fluid pathway.The diagnosis of type II neurofibromatosis (NF-II) was considered pre-operatively. After surgery, postoperative histopathology confirmed the diagnosis of ATRT.After ventriculo-peritoneal (VP) shunt, no evidence of tumor was inspected in cerebrospinal fluid, and enhancement MRI showed heterogeneous contrast signal on dumbbell shape tumor. We executed an incomplete microsurgery for dumbbell shape lesion in left auditory nerve distribution area and the fourth ventricle for differential diagnosis and facilitating further treatment.The patient did not recover well postoperatively and suffered from severe pulmonary infection. Refusing further intervention in view of poor prognosis of ATRT, the patient was transferred to another hospital for rehabilitation care. The patient died from progressive tumor and respiratory failure after 2 months.The diagnosis of ATRT can be challenging, in our case due to the disturbance of bilateral auditory nerve distribution area tumors. Under MRI, Irregular frontier, obvious mutual high and low signal on T2-weighted image, growing along cerebrospinal fluid pathway, and heterogeneous contrast enhancement should lead the clinician to strongly consider ATRT.