Intracranial extra-axial chondromas: clues to computed tomography and magnetic resonance imaging diagnosis

AIM

We aimed to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of intracranial extra-axial chondroma.

MATERIAL AND METHODS

We retrospectively evaluated the imaging findings of CT and MR examinations of six patients (three men and three women, aged 21-66 years) with histopathological diagnoses of intracranial extra-axial chondroma.

RESULTS

Four tumors were located in the frontal region and two in the cavernous sinus. All the tumors showed low signals on diffusion-weighted images and high signals on apparent diffusion coefficient maps without restricted diffusion. There was no perifocal edema in all the tumors. Cavernous sinus chondromas were associated with bone erosion and anterior displacement of the internal carotid arteries, but without calcification. Calcification was present in all frontal chondromas. All the tumors revealed low signals on T1-weighted MR images. Frontal chondromas revealed mixed signals, but cavernous sinus chondromas were brightly hyperintense on T2-weighted MR images. No enhancement was detected in the two chondromas. An intense homogeneous enhancement was detected in a cavernous sinus chondroma.

CONCLUSION

The imaging appearances of frontal extra-axial chondromas and cavernous sinus chondromas may have different imaging appearances. Although there is a wide range of imaging findings, the absence of restricted diffusion, perifocal edema, enhancement, and presence of low signals on T1-weighted MR images in a well-circumscribed calcified extra-axial mass should suggest an intracranial chondroma.

Magnetic resonance imaging criteria for prediction of isocitrate dehydrogenase (IDH) mutation status in patients with grade II-III astrocytoma and oligodendroglioma

BACKGROUND

IDH mutation status is an important prognostic marker for glial tumors, which is detected immunohistochemically after surgery. Since this method is invasive, easy and noninvasive magnetic resonance imaging (MRI) methods have recently been used in predicting the IDH mutation status. However, there is currently no standard MRI technique to predict IDH mutation. We analyzed the value of conventional MRI to predict IDH mutation and its effect on survival among grade II-III astrocytoma and oligodendroglioma patients.

MATERIAL AND METHODS

We included WHO grade II-III astrocytoma and oligodendroglioma patients who underwent surgery at Bahcesehir University Goztepe Medical Park Hospital. All patients were analyzed according to their immunohistochemical IDH mutation status. Preoperative conventional MRI studies with respect to their location, diffusion restriction, contrast enhancement, calcification and hemorrhage on susceptibility-weighted image (SWI) or T2*- weighted imaging (T2*WI), and T2 -FLAIR mismatch properties were retrospectively assessed by a neuroradiologist. The relation between MRI characteristics and IDH mutation was analyzed using a chi-square test. The sensitivity and specificity of radiological IDH mutation were determined by ROC analysis. The impact of IDH mutation on survival was also analyzed by Kaplan-Meier tests.

RESULTS

IDH mutation was found to be positive in 82.5% of tumors histopathologically and 54.4% radiologically. The sensitivity and specificity were 63.8% and 90%, respectively (Area under the curve/AUC = 0.369, p = 0.08). IDH wild gliomas were predominantly diffusion-restricted tumors. IDH mutant tumors were less likely to have contrast enhancement and had lower grades compared to the IDH wild tumors. The median survival time could not be reached and the overall survival was not related to any tumor characteristics or IDH mutation.

CONCLUSIONS

Conventional MRI predicts IDH-mutation status in Grade II-III astrocytoma and oligodendroglioma. Contrast-enhancement and restricted diffusion were strongly associated with grade III astrocytoma and oligodendroglioma, IDH-wild type. Location, T2-FLAIR mismatch, and SWI did not contribute to making a decision on the IDH mutation status. There was no significant difference between the survival times of patients and their IDH status.

Intracranial extra-axial mesenchymal chondrosarcoma in a 16-month-old patient with a literature review of pediatric patients

Mesenchymal chondrosarcoma is a rare high-grade malignant subtype of chondrosarcoma that is characterized by undifferentiated, round, or spindled mesenchymal cells, interspersed with islands of hyaline cartilage. We report a primary intracranial extra-axial mesenchymal chondrosarcoma in a 16-month-old patient with a review of the literature focusing on intracranial extra-axial MCs with or without skull involvement in pediatric patients, including differential diagnosis. The patient was admitted with a swelling in the right temporooccipital region. There was intracranial extra-dural extension of the mass, which abuts the neural parenchyma without any invasion. A complete tumor resection was performed. Pathological diagnosis was mesenchymal chondrosarcoma. The patient was free of symptoms after surgery.

Primary Sonic Hedgehog-activated dorsal brainstem medulloblastoma and ipsilateral cerebellar atrophy in an adult

Medulloblastoma (MB) that arises outside the cerebellum from cells of the dorsal brainstem is rare. The most common subtype of MB in the dorsal brainstem is the Wingless (WNT) subtype that contains activating mutations in the WNT pathway effector CTNNB1. Ipsilateral cerebellar hemi-atrophy with a brainstem tumour is a finding that is usually documented with brainstem gangliogliomas as a possible specific imaging sign. We present a case of a 23-year-old female with progressive headache, imbalance on walking, double vision and difficulty in swallowing for a year. Magnetic resonance imaging demonstrated a mass with prominent restricted diffusion on the dorsal surface of the lower brainstem with ipsilateral cerebellar atrophy. The final histopathological diagnosis was a Sonic Hedgehog (SHH)-activated and TP53 wild-type primary lower dorsal brainstem MB. Primary SHH-activated TP53 wild-type dorsal brainstem MB is extremely rare, and as far as we know, the association of the tumour with ipsilateral cerebellar hemi-atrophy in an adult has never been reported. MB should be included in the differential diagnosis of focal dorsal brainstem tumours, even in the presence of ipsilateral cerebellar hemi-atrophy.

Breast Carcinoma Metastasis to the Medial Rectus Muscle: Case Report

A 63-year-old woman with metastatic breast carcinoma presented to the ophthalmology clinic with diplopia and right abduction deficit. Magnetic resonance imaging showed isolated enlargement of the right medial rectus muscle. Biopsy of the enlarged muscle revealed metastasis of breast carcinoma. Ocular motility deficit in a patient with breast carcinoma should raise suspicion of metastasis to the orbit involving the extraocular muscles. Orbital imaging and biopsy are necessary for diagnosis and appropriate treatment.

Successful treatment of late-onset nevus comedonicus with Er:YAG laser

Nevus comedonicus, a rare congenital hamartoma of the pilosebaceous unit, is characterized by keratotic plugging. It usually occurs after birth and during early childhood. It rarely appears in adulthood. Despite the benign nature of the condition, it usually requires treatment due to aesthetic reasons. Several treatments have been reported in nevus comedonicus, most of them resulting with recurrences. Here, we report a case of nevus comedonicus with adult onset, successfully treated with erbium-doped yttrium aluminum garnet (Er:YAG) laser therapy.

Posterior fossa astroblastoma in a child: a case report and a review of the literature

A 4-year-old girl presented to the hospital with a progressive headache, difficulty walking, and persistent daily vomiting for 3 weeks. Papilledema was observed on fundoscopic examination. A large left cerebellovermian tumor with "bubbly" appearance was discovered. Total removal of the tumor mass was performed, and a diagnosis of low-grade astroblastoma was made. Adjuvant radiotherapy was performed due to the risk of recurrence. The patient is disease-free and has been kept on close follow-up for 6 months. The occurrence of posterior fossa astroblastoma has been rarely reported in the literature. Thus, when a "bubby" appearance enhancing cystic solid tumor is located on the cerebellar hemisphere in a child, an astroblastoma should also be included in the differential diagnosis.

Progress of an isolated collagenoma during pregnancy

Collagenomas are connective tissue naevi composed predominantly of collagen. Isolated collagenomas are usually localized to a single body region, acquired, and of rare occurrence. We describe a patient with an isolated collagenoma that showed an increase in size during pregnancy and regressed afterwards.

Falcine Myxoid Chondrosarcoma: A Rare Aggressive Case

Chondrosarcoma is the second most common primary malignancy of bone after osteosarcoma. Cranial primary chondrosarcomas mostly originate from the skull base cartilage formation zones. Parasagittal falcine origin is very rare for primary extra-skeletal intracranial chondrosarcomas. We report a rare case of primary myxoid chondrosarcoma at falx cerebri. The patient was a 35-year-old lady with right arm and leg weakness. Her brain magnetic resonance imaging depicted a left parasagittal mass lesion attached to the falx cerebri. En bloc resection via left frontal craniotomy was performed. Three more local recurrences occurred in 9 months’ time since the index surgery, which were all managed with re-surgeries and/or adjuvant stereotactic radiosurgeries. This is the second case of myxoid type parasagittal chondrosarcoma but with the most protracted disease course. Even though surgery remains the mainstay of treatment for parasagittal chondrosarcomas, adjuvant therapy might be necessary in aggressive ones.

Relapsed Wilms' tumor with multiple brain metastasis

Wilms' tumor is the most common malignant renal tumor in childhood. The brain metastasis of a Wilms' tumor with anaplastic histopathology is rare. We present the case of an 8-year-old girl with Wilms' tumor, who presented with multiple brain metastases 5 years after her primary diagnosis. The brain masses were diagnosed after a generalized tonic-clonic seizure attack. The big solid mass in the cerebellum was resected, and whole-brain radiotherapy was performed, after which, she succumbed to her disease. In the case of clinical suspicion, cranial surveillance should be included in the routine clinical work-up for Wilms' tumor. Combined aggressive therapy (surgery+radiotherapy+chemotherapy) should be applied whenever possible, for both better survival and palliative aspects.

Melanotic schwannoma of the L5 root

Melanotic neoplasm of the central nervous system is rare and the majority of them are metastatic. Melanotic schwannoma (MS) is an unusual variant of nerve sheath neoplasm accounting for less than 1% of primary nerve sheath tumors. A case involving a 36-year-old man with MS at the L5 root is presented. Surgery, differential diagnosis, radiology, histology, and treatment of this rare entity are discussed.

Isolated third ventricle glioblastoma

INTRODUCTION

Glioblastoma is the most common and the most malignant type of gliomas. Cerebral hemispheres are usual locations for gliomas. Isolated third ventricular presentation is very rare for glioblastomas. A new case of isolated third ventricular glioblastoma has been presented in this report.

CASE DESCRIPTION

A 36-year-old woman was admitted to outpatient clinic with headache, blurred vision and confusion. A head CT scan and MRI had showed third ventricular mass lesion with obstructive hydrocephalus. Previous to her admission to our clinic, a ventriculo-peritoneal shunt had been inserted and her hydrocephalus had been relieved to some extent in acute settings. In our clinic, stereotactic biopsy was performed and a second ventriculoperitoneal shunt was inserted from the opposite site. Histopathological diagnosis was glioblastoma. Radiotherapy and chemotherapy were started immediately after the surgery. Patient's hydrocephalus has resolved and she was well at post-operative 6th month.

DISCUSSION AND EVALUATION

In differential diagnosis list of the tumors presenting in the third ventricle, there are plenty of tumors such as colloid cyst, meningioma, germinoma, craniopharyngioma, lymphoma, choroid plexus papilloma, subependymal giant cell astrocytoma, chiasmatic and hypothalamic benign astrocytoma. Ring enhancement of this region pathology is a peculiar sign for glioblastoma, yet not pathognomonic. Tumor histology is crucial to yield the final diagnosis.

CONCLUSION

Management of obstructive hydrocephalus, making histopathological diagnosis, starting adjuvant radiotherapy and chemotherapy in isolated third ventricular glioblastomas is a safe and effective approach when we consider malignant nature and intractable progress of glioblastomas.