Fat in the brain: Facts and features

The presence of fat within a lesion in the brain is not only easy to identify on both CT/MRI but also can help narrow the differential. The purpose of this paper is to illustrate the spectrum of common and rare fat-containing lesions in the brain that are encountered in clinical practice. This paper intends to discuss 15 such lesions which are confirmed by MRI findings and histopathological correlation. We divided the spectrum of fat-containing lesions into lesions with adipose cells, lesions with cholesterol-rich content and tumours with lipomatous differentiation/transformation. Knowledge of these common and rare fat-containing lesions is essential for making the right diagnosis or narrowing the differential diagnosis.

Myriad of MR imaging phenotypes of primary central nervous system lymphoma in a cohort of immunocompetent Indian patient population

PCNSL (primary central nervous system lymphoma) is a chemosensitive and radiosensitive tumor, and early diagnosis has a significant impact on management. Unlike many other brain tumors, radical surgical excision of PCNSLs is not indicated because these lesions are highly infiltrative and even partial resection leads to a bad prognosis. The goal of this study is to highlight the unusual radiological presentation of PCNSLs and increase the awareness, familiarity, and global database of our observations that pose a challenge on management.

Fatal holocord recurrence of a pregnancy-related, low-grade spinal ependymoma: case report and review of an unusual clinical phenomenon

INTRODUCTION

Pregnancy-related spinal tumors (PRSTs) are unusual tumors that present during pregnancy or within a year after delivery. We describe a fatal holocord recurrence of a spinal ependymoma, which, to the best of our knowledge, is one of the most extensive PRSTs reported thus far.

CASE PRESENTATION

A 21-year-old primigravida presented at 6 months of gestation with urinary incontinence for 2 months and spastic paraparesis for 1 month. MRI showed a conus intramedullary lesion from T10 to 12. Near-total resection of the lesion was performed. The histopathological diagnosis was that of a cellular ependymoma (WHO grade II). The patient presented 6 months later with progressive quadriparesis and breathing difficulty. MRI demonstrated holocord recurrence of the tumor with edema extending to the pontomedullary junction. The patient succumbed to respiratory failure before decompression of the tumor could be performed.

DISCUSSION

This case highlights an unusual clinical course of a pregnancy-related, low-grade spinal ependymoma. The possible hormonal and genetic mechanisms underlying the aggressive involvement of the entire spinal cord by the recurrent tumor are discussed in the light of a literature review. Future studies may shed light on the possibility of utilizing these mechanisms as therapeutic targets to alter the clinical course of aggressive spinal ependymomas.

Sellar-Suprasellar Paraganglioma: Report of 2 Cases and Review of Literature

BACKGROUND

Intracranial paragangliomas are infrequent and those occurring in the sellar-suprasellar region are rare, with only 31 cases described in literature.

CASE DESCRIPTION

We describe 2 cases of sellar-suprasellar paragangliomas in the light of a literature review. The first patient was a 13-year-old boy who presented with an intensely enhancing lesion in the sellar-suprasellar region with multiple flow voids within. Resection of the lesion was limited to a biopsy in view of its hypervascular nature. A second attempt at resection following partial embolization of the lesion was also unsuccessful. The tumor showed progressive reduction in size following radiotherapy. The second case was a 20-year-old man who presented with a similar tumor in the same location. He also had a probable metastatic deposit in the foramen of Magendie. An attempted surgical resection of the suprasellar lesion was abandoned after a biopsy. The patient improved symptomatically after radiotherapy.

CONCLUSIONS

We report 2 cases of paraganglioma occurring in a rare location. Presence of flow voids within tumors in the sellar-suprasellar location should alert the surgeon to this entity. The hypervascular nature of these tumors may limit the extent of resection. In cases of inadequate tumor decompression, or if there is evidence of growth of residual tumor, radiotherapy can help to stabilize the disease.

Aggressive Primary Pediatric Intracranial Malignant Melanoma: Sphinx of the Tissue Diagnosis

It is often intriguing to suspect and confirm the diagnosis of primary malignant melanoma (PMM) in the brain without any evidence of neurocutaneous melanosis. We report a 16-year-old male patient with malignant melanoma which intraoperatively was small sized, soft, fleshy, hemorrhagic in appearance resembling hematoma. Interestingly, the histopathology showed prominent papillary architecture with a differential diagnosis of papillary meningioma and ependymoma and perplexed the tissue diagnosis. This case is discussed in light of very uncommon occurrence of intracranial PMM in pediatric age group, enigmatic histological features, and aggressive nature of lesion with rapid progression despite complete excision following radiation therapy.

Unusual Radiological Presentation of Intracranial Dermoid Cyst: A Case Series

Intracranial dermoids are rare congenital lesions of the brain that account for < 1% of all intracranial tumors. Even though they are rare, typical computed tomography (CT) scan and magnetic resonance imaging (MRI) features along with location allow radiological diagnosis in the majority of patients. Radiologically, dermoid cysts typically appear as nonenhancing low-density masses on CT scan and are hyperintense on T1-weighted (T1-W) MRI sequences with variable signal on T2-W sequences. We describe two cases of dermoid with unusual imaging appearance with the presence of mural nodule in both the cases. The recognition of atypical radiological features can avoid diagnostic pitfalls and is clinically relevant for overall surgical management.

Tree-in-bud Appearance in the Brain: Fungal Granuloma on Contrast Magnetic Resonance Imaging

We describe a case of dural-based homogenously enhancing fungal granuloma in a 29-year-old male who presented with 3 months history of headache. The peculiarity of the case was that there were streaky areas of enhancement around the lesion in the brain parenchyma which resembled tree-in-bud like appearance. The patient underwent surgery and histopathological analysis revealed numerous Aspergillus hyphae. To the best of our knowledge, this is the first case report of a fungal granuloma with atypical parenchymal enhancement pattern.

Clinicopathological and imaging features of lipoastrocytoma: Case report

Lipidized tumors of the central nervous system are very uncommon, with only a few cases described. We report a case of a 25-year-old woman with a tumor involving the left premotor area. She underwent gross total excision. Histologically, the tumor was composed of glial fibrillary acidic protein-positive glial cells with areas of lipidization. A diagnosis of lipoastrocytoma was rendered. At three-year follow-up she was doing well, supporting the presumed favorable prognosis of these uncommon tumors. Absence of xanthochromic appearance, mitotic activity, necrosis and poor reticulin activity are the differentiating features from the pleomorphic xanthoastrocytoma. We highlighted that these tumors involve the adult and pediatric population and distribute in both supratentorial and infratentorial compartments as well as in the spinal cord.

Pituitary apoplexy presenting as a peripheral rim enhancing parasellar mass lesion with dural enhancement along the tentorium

Pituitary apoplexy is a potentially life-threatening clinical condition caused by rapid enlargement of a pituitary adenoma because of haemorrhage or infarction. The clinical features are typically acute in onset. We report an interesting case of 25-year-old man with complaints of sudden onset of headache and ophthalmoplegia in the right eye one month previously. He had ptosis and complete ophthalmoplegia in the right eye with visual acuity 6/24 and 6/12. Imaging showed a peripheral rim-enhancing mass lesion in the right parasellar and cavernous sinus with a dural tail. He underwent craniotomy and subtotal excision of the lesion. Histopathology was reported as pituitary apoplexy. Hormonal analysis was within normal limits. At two years of follow-up he had complete resolution of ophthalmoplegia and improvement in his vision. It is very uncommon to see pituitary apoplexy evolved in right parasellar region presenting as peripheral rim-enhancing mass lesion.

Giant multi-compartmental suprasellar Rathke's cleft cyst with restriction on diffusion weighted images

Rathke's cleft cysts are congenital lesions seen in sellar-suprasellar regions. We report a case of giant Rathke cyst in a 43-year-old patient with multi-compartmental involvement who presented with seizures with almost normal visual acuity. We discuss radiological and pathological features of various differential diagnoses for the giant suprasellar Rathke's cyst.

Ampullary carcinosarcoma with osteosarcomatous, small cell neuroendocrine carcinoma and conventional adenocarcinoma components; First report

Caracinosarcomas are tumours with diverse epithelial and mesenchymal differentiation. They most commonly occur in the female reproductive organs and upper aero digestive tract. They are relatively rare in the gastrointestinal tract and affect the oesophagus most commonly. Ampullary carcinosarcomas are exceptionally rare. We report a case of ampullary carcinosarcoma in a 67-year-old male, with osteosarcomatous, small cell carcinoma and conventional adenocarcinoma components. To the best of our knowledge, this is the first reported case of its kind.

Primary intradural sacral epidermoid in a nondysraphic spine: Case report and review of literature

The occurrence of epidermoids within the spinal canal is uncommon. Most of the reported spinal epidermoids (SEs) have been described in the thoracic or lumbar regions. They occur either following trauma or in the setting of coexistent spinal dysraphism. The authors describe an unusual case of a 28-year-old lady who presented with long-standing back pain and urinary incontinence. Magnetic resonance imaging (MRI) of her spine demonstrated a sacral SE without any coexistent spinal dysraphism. The diagnosis of an epidermoid was confirmed by histopathological examination following laminectomy and excision. To the authors’ best knowledge, this is the third case of a sacral SE occurring in a non-dysraphic spine. The case is discussed in the light of a relevant literature review.

Aggressive solitary intracranial metastatic malignant melanoma from a primary mediastinal tumour

Malignant melanoma is the third most common tumour to cause cerebral metastases, following breast and lung cancer. Central nervous system metastases occur in 10-40% of patients with melanoma. Intracranial metastasis from a primary malignant melanoma of the anterior mediastinum is uncommon. We report a case of solitary intracranial metastatic melanoma arising from a primary mediastinal tumour. We then discuss the clinico-radiological features and treatment options.

Primary parietal myeloid sarcoma

Intracranial occurrence of myeloid sarcoma without any evidence of systemic hematological disorder is uncommon. We report the case of a 17-year-old girl who presented with features of raised intracranial pressure and paraparesis of short duration. Magnetic resonance imaging showed a 6 cm bilateral middle 1/3^rd para sagittal contrast enhancing extra-axial mass with mass effect. The tumor was subtotally excised. Histology and immunohistochemistry proved to be a myelosarcoma. Further evaluation done with peripheral blood smear and bone marrow biopsy ruled out the possibility of leukemia or myeloproliferative disorder. She was referred for chemotherapy and clinically showed improvement after 6 months of follow-up. Authors report a case of intracranial myelosarcoma which closely resembled meningioma both radiologically and in intraoperative morphological appearance. Authors discuss in detail the radiological and histological features of myelosarcoma along with differential diagnoses and treatment options.

Anaplastic hemangiopericytoma in the frontal horn of the lateral ventricle

Intracranial hemangiopericytomas are uncommon tumors, and their intraventricular occurrence is even rarer. We report a 40-year-old man who presented with raised intracranial pressure. His MRI showed a 3.3 × 3.2 × 3.2 cm heterogeneously enhancing lesion in the left frontal horn obstructing the foramen of Monro and causing hydrocephalus. The tumor was excised through an anterior interhemispheric, transcallosal approach, and histopathology revealed an anaplastic hemangiopericytoma (World Health Organization grade III). To our knowledge this is the first report of this rare pathology being located within the frontal horn of the lateral ventricle.

Occam's razor in the management of ventriculoperitoneal shunt dysfunction: Diagnosis and management of an unusual pediatric case

Ventriculoperitoneal (VP) shunt surgery is probably the commonest surgical procedure in neurosurgery. Belying its technical simplicity is the myriad complications associated with it. Shunt malfunction is a common complication associated with this surgery, second only to shunt related infections, which may be associated with it. Sterile cerebrospinal fluid (CSF) eosinophilia (CE) has been reported with VP shunts, which may or may not be related to the dysfunction. Eosinophilia in the CSF has also been associated with a number of other conditions including parasitic infestations in the brain. This may be unrelated to the shunt surgery. We present a case of a child, operated earlier for hydrocephalus, who presented with sub-acute loss of vision and bilateral oculomotor paresis. CSF from a chamber tap revealed eosinophilia. The commonest presenting symptom of shunt malfunction is raised intracranial pressure. There are no reports in the literature of VP shunt malfunction presenting with bilateral oculomotor paresis and decreased visual acuity. The associated CE complicated the clinical picture, especially since the initial brain radiology was normal. We discuss the clinical differential diagnosis of this very interesting presentation, management dilemmas and outcome in this child. This rare clinical presentation was found to be the result of a shunt malfunction and not due to any rare parasitic infestation of the brain. Occam's razor dictates that the simplest explanation in a given situation is usually the most accurate, as is seen in this case.

Should adjuvant radiotherapy be recommended for pediatric craniopharyngiomas?

Intracranial tumors secondary to radiotherapy are rare. In this group gliomas are the rarest. Only 6 cases of glioblastoma multiforme (GBM) have been reported in patients undergoing radiotherapy (RT) for craniopharyngiomas of which only 4 have been in children less than 18 years of age. In recent years RT has become a mainstay of adjuvant therapy for recurrent or partially excised craniopharyngiomas. We report a child of 12 years who had previously undergone RT for a suprasellar craniopharyngioma and presented 10 years later with a GBM. This is the 5th pediatric case in literature demonstrating a GBM after RT for a craniopharyngioma. The implications of subjecting the pediatric population to RT for a benign lesion versus the outcome of gross total removal and management of RT induced tumors is discussed and the need to avail of safer alternatives such as stereotactic radiosurgery is stressed.

Giant calvarial desmoplastic fibroblastoma

We describe to our knowledge the first patient with giant desmoplastic fibroblastoma of the calvarium in a 20-year-old woman whose tumor first appeared at the age of 5 years. We also discuss the histopathological differential diagnosis, management dilemmas and complications of desmoplastic fibroblastoma.

Congenital giant plexiform neurofibroma with occipital calvarial dysplasia in association with meningoencephalocele in neurofibromatosis Type 1 and segmental neurofibromatosis: report of 2 cases

Giant plexiform neurofibroma (GPNF) of the scalp is an extremely rare lesion reported in association with neurofibromatosis. Occipital location of GPNF is even more infrequent, especially in association with occipital dysplasia (OD). The authors report 2 pediatric cases of GPNF associated with OD. The first case had an associated meningoencephalocele, and the second had large vascular channels within the lesion and the dominant ipsilateral transverse sinus lying in the center of the calvarial defect. The authors present these 2 unusual cases with a review of literature and discuss the radiological findings, theories of etiopathogenesis of the OD, and management dilemmas.

Skull-base Ewing sarcoma with multifocal extracranial metastases

Intracranial occurrence of Ewing sarcoma (ES) is unusual, with a skull-base location being anecdotal. We report a 29-year-old man who presented with rapidly progressive ophthalmoplegia, and was found to be harboring an infiltrative lesion involving the sphenoid sinus, sella, and clivus. He underwent trans-sphenoidal decompression of the lesion which was histologically suggestive of ES. He developed paraparesis 2 weeks after commencing adjuvant therapy. Imaging revealed two thoracic extradural lesions and florid vertebral and pulmonary metastases. This is the first report in indexed literature of a primary intracranial ES on the skull-base with disseminated extracranial disease.

A nondysraphic paraspinal mass and a ventricular septal defect: unusual components of diabetes-induced mesodermal derangement

Solitary paraspinal masses in the pediatric age group commonly occur secondary to spinal dysraphism, chronic inflammatory conditions, and tumors. We describe the unusual case of a 10-year-old boy with a nondysraphic, paraspinal mass that had occurred secondary to congenital spinal epidural lipomatosis (SEL) in the setting of poorly controlled maternal type-I diabetes mellitus. The mass was picked up along with a ventricular septal defect (VSD) on an antenatal ultrasonogram. This is the first report in literature of SEL presenting as a solitary paraspinal mass at birth, and in the unusual setting of an antenatal mesodermal derangement that simultaneously engendered a VSD.

Neurothekeoma of petrous apex: A rare entity

Intraosseous nerve sheath tumors are very rare tumors accounting for lesser than 0.2% of primary bone tumors. We present an 18-year-old female who presented with left facial paresis for the last 1 year. Magnetic resonance imaging (MRI) demonstrated expansile, multiseptated, enhancing bony lesion in the left petrous apex. There was also abnormal enhancement of the 7-8th nerve complex within the internal auditory canal. Tumor was excised by subtemporal extradural approach. The lesion was diagnosed as intraosseous neurothekeoma on histopathology. This is an extremely rare tumor and its MRI appearance in this location is being described for the first time in literature.

Solitary thoracic vertebral body cysticercosis presenting with progressive compressive myelopathy

Common bony spinal pathologies that could present with progressive spasticity include vertebral body tumors or chronic infections of the spine. Cysticercosis of the spine commonly has an intramedullary occurrence. The authors discuss the presentation and management of a rare case of solitary vertebral cysticercosis that presented with lower-limb spasticity and sphincter involvement.

Solitary cerebellous metastasis after prolonged remission in a case of uterine cervical adenocarcinoma

Intracranial metastasis of a uterine cervical carcinoma is a very rare occurrence. These metastases are characteristically multiple, supra-tentorial, associated with multiple systemic dissemination, usually occur relatively late in the course of the disease, and are most often seen in squamous carcinomas. We present an unusual case which defied these characteristics. This patient was in long-term remission (11 years), presented with a solitary cerebellous metastases, had no evidence of other systemic spread, and the pathology was an adenocarcinoma. We present this rare case with interesting clinical ramifications. This is probably the longest duration of remission prior to the metastasis in the published literature.

Pontomedullary white epidermoid: a rare cause of tinnitus

Intracranial epidermoid cysts are relatively rare congenital inclusion cysts. They are the third most common cerebellopontine angle cistern mass after vestibular schwannoma and meningioma. White epidermoid is a rare variant. We present the first case, to our knowledge, of a white epidermoid cyst anterior to the pontomedullary junction, emphasising its imaging appearance, location and the importance of pre-operative diagnosis, which may reduce operative complications.