Tumefactive demyelinating lesions versus CNS neoplasms, a comparative study.

BACKGROUND: Differentiating tumefactive demyelinating lesions (TDL) from neoplasms of the central nervous system continues to be a diagnostic dilemma in many cases. OBJECTIVE: Our study aimed to examine and contrast the clinical and radiological characteristics of TDL, high-grade gliomas (HGG) and primary CNS lymphoma (CNSL). METHOD: This was a retrospective review of 66 patients (23 TDL, 31 HGG and 12 CNSL). Clinical and laboratory data were obtained. MRI brain at presentation were analyzed by two independent, blinded neuroradiologists. RESULTS: Patients with TDLs were younger and predominantly female. Sensorimotor deficits and ataxia were more common amongst TDL whereas headaches and altered mental status were associated with HGG and CNSL. Compared to HGG and CNSL, MRI characteristics supporting TDL included relatively smaller size, lack of or mild mass effect, incomplete peripheral rim enhancement, absence of central enhancement or restricted diffusion, lack of cortical involvement, and presence of remote white matter lesions on the index scan. Paradoxically, some TDLs may present atypically or radiologically mimic CNS lymphomas. CONCLUSION: Careful evaluation of clinical and radiological features helps in differentiating TDLs at first presentation from CNS neoplasms.

Tumour-like presentation of brainstem tuberculoma: a lesson learnt.

Brainstem tuberculoma is diagnostically challenging as it lacks clinical clues and imaging mimics a high-grade glioma (HGG). We report the case of an adolescent girl diagnosed with brainstem HGG, who was referred to our centre for Gamma Knife. Initial MRI showed a pontomedullary junction, ring-enhancing lobulated lesion demonstrating distinct central hypointensity on T2-weighted (T2W) and fluid-attenuated inversion recovery (FLAIR) images with extensive vasogenic oedema. An alternative diagnosis of infection was entertained, and biopsy was suggested; however, the parents opted for a trial of alternative treatment. Suboccipital craniotomy and debulking were only performed 3 months later when her symptoms worsened, and MRI revealed enlargement of the lesion. A cheesy 'tumour' was noted intraoperatively; histopathological findings later confirmed chronic granulomatous inflammation. In an endemic area, a high index of suspicion of a tuberculoma is vital specifically in the presence of central T2W/FLAIR hypointensity of a ring-enhancing lesion.

Unusual presentation of lung carcinoma with pituitary metastasis: a challenging diagnosis and sodium management dilemmas.

Summary: Pituitary metastasis (PM) is a rare complication of an advanced malignancy. Albeit rare, PM can be more detected and achieve a longer survival rate through frequent neuroimaging and newer oncology therapies. Lung cancer is the most frequent primary site, followed by breast and kidney cancers. Patients with lung cancer generally present with respiratory symptoms and are commonly diagnosed at an advanced stage already. Nevertheless, physicians should be mindful of other systemic manifestations as well as signs and symptoms related to metastatic spread and paraneoplastic syndromes. Herein, we report the case of a 53-year-old woman who presented with PM as the first sign of an undiagnosed lung cancer. Initially, her condition was a challenging diagnosis and was even complicated with diabetes insipidus (DI), which can present as severe hyponatremia when coexisting with adrenal insufficiency. This case also highlights that treating DI with antidiuretic hormone (ADH) replacement was complicated by extreme difficulties in attaining satisfactory sodium and water balance during the clinical course, with the possibility of coexistent DI and syndrome of inappropriate ADH secretion because of the underlying lung cancer. Learning points: When patients present with pituitary mass and diabetes insipidus (DI), pituitary metastasis should be considered as an initial differential diagnosis. DI caused by pituitary adenoma is rare and is typically a late finding.DI can present as severe hyponatremia when coexisting with adrenal insufficiency.Cortisol can directly inhibit endogenous antidiuretic hormone (ADH) secretion. Patients with adrenocorticotropic hormone deficiency will have increased tonic ADH activity and subsequently reduced capacity for free-water excretion. However, when on steroid therapy, patients should be monitored for possible DI because steroids can restore free-water excretion.A substantial change in serum sodium after desmopressin treatment should eliminate the possibility of desmopressin overdose or coexistence of DI and syndrome of inappropriate ADH secretion in patients with lung cancer. Therefore, frequent monitoring of serum sodium concentrations is crucial.