Intracranial germ cell tumors are uncommon and account for only 0.3–3.4% of all intracranial tumors. Teratomas are a subset of these neoplasms, and their finding in brain structures is exceptionally rare, and occurrence within the skull base is quite novel. The authors report the case of a 57-year-old male patient who presented with vision changes, incontinence, ataxia, and altered mental status of 1 week’s duration. Imaging revealed a large intrasellar mass with suprasellar extension, involvement of the ventricular system, and marked hydrocephalus with the enlargement of the lateral and third ventricles. The patient underwent a pterional craniotomy/transsylvian approach for resection of the mass. Postoperative histological examination of the resected mass was confirmatory for a mature cystic teratoma. This was followed by radiotherapy, stereotactic radiosurgery, and adjuvant radiotherapy. At the most recent followup, approximately 4 years later, the patient is doing well with improved vision since the operation. This report highlights our experience with a teratoma in a very unusual location, and we review the relevant literature.
Intracranial germ cell tumors of the central nervous system are rare and usually occur in the midline of the brain, particularly at the pineal region and neurohypophysis [
Teratomas comprise only 0.5% of all intracranial tumors [
The patient is a 57-year-old man who presented in July 2009 with decreased vision bilaterally, left sided facial weakness, ataxia, and short-term memory loss. The patient had also presented previously with a history of seizures, most recently a few months prior to the current presentation. A craniopharyngioma or another parasellar mass was suspected, and an ophthalmology consult was obtained.
MRI showed a large intrasellar mass with considerable suprasellar extension and chiasmatic compression with the displacement of the inferior frontal lobe. There was also hydrocephalus with gross enlargement of the lateral and third ventricles (Figure
Sagittal T1 with contrast MRIs (a) and coronal T1 with contrast MRIs (b) showing a large sellar mass with significant suprasellar infiltration.
The patient was determined to be an excellent candidate for surgery, the only other comorbidity being glaucoma treated with Lumigon. Because of the location of the tumor, it was decided that the patient would undergo a right pterional craniotomy/transsylvian approach for the resection of the tumor and the placement of a ventriculostomy catheter. After placement of a ventriculostomy catheter, the major part of the craniotomy followed. The first line of incision was made in a curvilinear fashion that began at the area 1 centimeter anterior to the tragus of the ear near the root of the zygoma. It curved superiorly up around the temporal bone and parietal bone and then extended toward the midline frontal bone. Dissection proceeded to expose the appropriate amount of cranial anatomy. The tumor was eventually exposed by opening up the sylvian fissure to separate the frontal lobe from the temporal lobe. The tumor was noted to have both cystic and solid components. Fluid aspirated from the cystic component was thick and yellow, with the appearance of oil or cholesterol. There were odd appearing components to the tumor, including what appeared to be yellow clumps of hair embedded within fatty deposits. There were also several firm calcified structures that appeared to be compressing the left optic nerve. The optic nerve itself appeared to be blanched in color without a very good blood supply. There were several firm calcified deposits of tumor that were tightly adhered to the optic chiasm, right carotid artery, and cranial nerve III complex. Though these were tightly adhered and it was decided to be too dangerous to completely resect, the high quality of decompression performed made it so that it was not felt that complete removal of these structures was clinically indicated.
Specimens taken during the operation were sent to pathology and revealed portions of skin with skin appendages, innumerable hairs, and keratinous debris (Figure
Hematoxylin and eosin (H&E) stained sections of the tumor resection. (a) Cyst contents with hair, keratinous material, and debris. ((b) and (c)) Cyst wall composed of skin and its appendages. Original magnifications: 100x (a), 12.5x (b), and 40x (c).
Upon closure of the procedure, there appeared to be no complications, and postoperative condition was deemed stable. Due to incomplete resection of tumor and risk of recurrence, external beam radiotherapy and eventually stereotactic radiosurgery were used as well as postoperative adjuvant therapy. The patient had a seemingly uncomplicated subsequent recovery and was discharged home. Though over the next month he had a slowly progressive decline in mental status and was admitted for observation. He was discharged soon after following close monitoring and recovery of his status. Since then, he has been watched carefully with frequent clinic appointments and imaging studies. At the most recent followup, approximately 4 years later, he is doing well with significantly improved neurological status and vision.
Mature teratomas are well-differentiated tumors that are usually lobulated and often firmly adhere to neighboring structures [
Intracranial germ cell tumors are rare comprising about 0.3% to 3.4% of all intracranial tumors [
Teratomas are a type of germ cell tumors containing tissue elements of each of the three germ cell layers: endoderm, mesoderm, and ectoderm [
Clinical and radiographic findings can make it difficult to distinguish a mature teratoma from a craniopharyngioma [
The typical treatment for mature teratomas is surgical resection, which was successfully done in this case. The deterioration of the patient after a period of improvement in mental status and ambulation may be due to hydrocephalus or due to chemical encephalitis from by-products of the tumor. Mature teratomas are benign and have been reported to have survival rates up to 93% at 10 years [
Suprasellar mature teratomas are exceptionally rare. However, because they mimic many other lesions, it is important to recognize this entity in the differential diagnosis and to obtain a thorough histological diagnosis. A multimodal approach for treatment is recommended with complete surgical resection, radiotherapy, and chemotherapy. Future reports on this rare location for a teratoma can help ascertain long-term outcomes.