(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25-year-old gentleman presented with short history of headache and gait disturbances. Radiology revealed a heterogeneously enhancing mass in the fourth ventricle extending from midbrain to pons. CT scan showed a hyperdense mass in the 4th ventricle. There was no calcification or cysts seen within the lesion. MRI showed a well defined mass in the fourth ventricle. The lesion was isointense on T1, hyperintense on T2 (Fig. 1A) and enhanced heterogeneously on contrast administration (Fig. 1B). The contrast images showed tumor infiltration into brain stem suggesting a poor plane of cleavage, better appreciated on sagittal MRI (Fig. 1C). FLAIR MRI showed slightly hyperintense lesion suggesting a cellular tumor (Fig. 1D). Though the lesion showed no calcifications or cysts or areas of bleed, the enhancement pattern and infiltration in the fourth ventricular floor suggested a radiological diagnosis of ependymoma. The lesion was operated through a midline suboccipital craniotomy. The lesion was yellow grey, not very vascular and was attached to the brain stem. A thin sliver of tumor adherent to the brain stem was left. Near total resection could be achieved.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

The patient is a 2.5 month old female who presented with weight loss, stridor, hypertonia, and abnormal visual tracking. She was the result of a full term pregnancy with no complications and unremarkable delivery. Of note, the neurological exam at that time was normal. She regained birth weight quickly but had weight gaining difficulties starting in the second month. There were additional developmental delays such as no social smile, no object tracking, nor engaging with environment. There was back arching noted while feeding.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25-year-old woman had a history of 4 episodes of epilepsy over two years without treatment. MRI showed that there was a solid circumscribed, hyperintense and nonenhancing tumor (Fig 1) measuring 6x4x4cm in the hippocampus. T1-weighted and T2-weighted scans showed mixed signals without calcification in the tumor and no peritumoral edema. The tumor was totally resected. Macroscopically, the surgical sample was bits and pieces. Histologically, the tumor included glial, neuronal and mixed glioneuronal populations. The spindle-shaped tumor cells showed diffuse growth and displayed characteristic angiocentric arrangements around small parenchymal vessels forming perivascular pseudorosettes. There were single or multilayered tumor cells arranged with ependymal features (Fig 2). The tumor cells of the hippocampal surface formed distinctive rosettes (Fig 3) which have not been previously described. The spindle tumor cells were bipolar with elongated nuclei and inconspicuous nucleoli. In some areas, the tumor cells were schwannoma-like (Fig 4). We could find single neurons interspersed within the tumor tissue. Necrosis and mitotic activity were absence. Immunohistochemistry was positive for GFAP (Fig 5), Vimentin and S-100 and negative for neurofilament protein, Syn, CgA and NeuN. EMA showed "dot-like" positive staining (Fig 6). The proliferation index was less than 1%. Epilepsy disappeared after the operation. We only follow-up four months till now and There was no evidence of recurrence on MRI at a four month follow-up.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25 year old African American female with no significant past medical history presented to the hospital with complaints of a severe headache and agitation for approximately one week. While in the emergency department, she became extremely agitated and violent, requiring physical restraints and benzodiazepine sedation. Her initial workup was unremarkable with the exception of a qualitative urine toxicology screen that was positive for cannabinoids. The patient was admitted to the inpatient psychiatry service for presumed acute psychosis. Within a few hours, she developed generalized seizures and required intubation for airway protection. A CT scan of her head, a brain MRI, and an EEG were negative for any acute intracranial pathology. Despite sedation and anti-epileptic medication, the patient continued to have persistent seizures and agitation. She was immediately transferred to the ICU where her sedation was increased and she was maintained on mechanical ventilation. She remained afebrile, had stable vital signs, and had an unremarkable physical exam. However, any time sedation was held she developed generalized tonic clonic seizure activity and had to be re-sedated. A work-up for acute status epilepticus was initiated, and the results of relevant laboratory tests are provided in Table 1.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

The patient is a 25 year-old male with no significant past medical history. He presented to his primary care physician complaining of a constant, throbbing left parietal headache for four to five days. He also had intermittent, generalized sweating accompanied by chills, fatigue, malaise, myalgias, and arthralgias for two to three days. Ten days prior, the patient had returned from a trip to India. He was born and raised there and visits yearly. He received no vaccinations prior to his trip and was never vaccinated for previous visits. The patient was afebrile with a completely unremarkable physical examination.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25 year-old male presents with high fever (105 degrees F) for approximately one week, accompanied by nausea, vomiting, arthralgias, and myalgias. He reports that he spent the past 15 months serving with the military in Afghanistan and only recently returned. He had been taking mefloquine for malarial prophylaxis but discontinued it several weeks-months ago.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25-year-old white male with a history of schizoaffective disorder was brought to the emergency room in February with a 24-hour history of difficulty breathing and not acting normally.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 25-year-old, previously healthy woman presented with a 3-year history of lumbago with radiation to the right lower extremity and was admitted to our hospital. Pain was of mechanical type and responded well to rest. Complete neurological examination was normal. Magnetic resonance imaging (MRI) showed two well-circumscribed isolated intradural masses at levels L2-L3 and S1-S2. One at level L2-L3 measured 3.2 cm in its longest axis. The other extending from S1-S2 measured 2.2 cm in its long axis. Both masses were heterogeneous in T2 and strongly enhanced after gadolinium injection (Figures 1a, 1b,1c). No other lesions were identified elsewhere on craniospinal axis by MRI. Both masses were completely resected. The patient was discharged ten days later. The MRI performed 10 months after surgery showed no recurrence of the tumors.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 26 year-old female initially noted blurry vision when looking towards the right. Three months later, she noted diplopia when looking towards the right side. Right abducens nerve palsy was documented by her ophthalmologist. Initial brain MRI performed four months after the onset of blurry vision showed a 4mm (AP) X3mm(transverse)X5mm (craniocaudal) area of enhancement anterior to the pons on the right side (Figure 1). Neurology coordinated an extensive serum screening for inflammatory, infectious, and metabolic causes, all of which came back negative. Two to three months later, she started experiencing daily pressure headaches felt mostly in the occipital and suboccipital regions. The follow-up brain MRI showed the presence of a prepontine/premedullary mass, measuring 23mm (AP) X34mm (transverse) X29mm (craniocaudal) (Figure 2). This mass was mostly solid but presented some cystic necrotic areas. The lesion, believed to be extra-axial, exerted mass effect on the pons and medulla without causing abnormal signal within the brainstem. The mass also caused asymmetry of the fourth ventricle without evidence of obstructive hydrocephalus. At the time of consultation with neurosurgery, approximately 7 months after the onset of her blurry vision, the patient reported difficulty swallowing solids for the last two weeks. Other than abducens nerve palsy, the rest of her physical exam was unremarkable. After review of the images with neuroradiology, the suspected diagnosis was a malignant nerve sheet tumor, most probably arising from the abducens cranial nerve. The investigation was completed with a spine MRI which demonstrated the presence of three subcentimetric enhancing nodules, interpreted as possible schwannomas or meningiomas (Figure 3). A catheter angiogram did not reveal any direct arterial feeder that could be embolized.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 27 year old female patient, presented with left hemiparesis. Brain MRI showed multiple cystic ring-enhancing lesions involving the cerebrum and cerebellum (Figure-1A). She has received anti-tuberculous treatment for a recent diagnosis with pulmonary tuberculosis, however, the brain lesions showed with no response. Investigations revealed no other medical conditions. She underwent craniotomy and one of the lesions was excised from the left parietal lobe. It consisted of an oval white to gray soft tissue mass with solid white cut surface measuring 1.2x0.8x0.9cm (Figure-1B).

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 27-year-old woman was admitted to hospital with a 5-months history of difficulty in swallowing, hoarseness and increasing headaches since the last gestation trimester of her second pregnancy. Concerning her previous history, she reported that the same symptoms had occurred during the first gestation and had fully resolved after delivery. On neurological examination, a facial paresis and deafness were present on the right side. The patient also presented a significant dysfunction of the right IX, X and XI cranial nerves.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

27-year-old lady with a history of upper extremity numbness and weakness.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

The patient was a 27-year-old white male with a history of possible mild mental retardation attributed to traumatic brain injury at the age of 10. He was hospitalized at an outside hospital with several weeks of diffuse lower abdominal pain, mild dizziness and nausea, with approximately 50 pounds weight loss over an uncertain period of time. Four days after admission, he had deteriorating levels of consciousness, requiring intubation for airway protection. He was unresponsive to painful stimuli. Oculocephalic reflexes were absent. He had an upgoing Babinski response bilaterally. EEG showed diffuse generalized slowing. CSF showed 31 RBCs/cu mm, 2 WBCs/cu mm, 96 mg/dl glucose and 58 mg/dl protein. Despite multimodal therapy, the patient's neurologic condition did not improve. Due to a dismal prognosis for neurological recovery, a decision was reached with his family to switch to comfort measures only. The patient passed away 13 days after admission.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

The patient is a 28 year old female who presented to an outside hospital with fatigue and easy bruising. She has a past medical history of cleft palate, type 2 diabetes, irritable bowel syndrome, and depression. She was found to have splenomegaly on physical exam. A complete blood cell count (CBC) was performed, which showed thrombocytopenia, borderline anemia, and neutropenia with a left shift. She was referred to a hematologist and a repeat CBC and bone marrow evaluation were performed:

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

28-year-old male with erythematous pruritic plaques with mild scales for a month, distributed over his left forearm, scrotum, left side waist and scalp (with alopecia).

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

In April 2006, a 28-year-old previously healthy man experienced headache, visual and aphasic speech disturbances. MR-imaging revealed a large, partly cystic mass of the left temporal lobe with significant contrast enhancement (Fig. 1). At surgical resection, due to infiltration of Wernicke's speech area, only subtotal tumor removal was achieved. Subsequent adjuvant therapy consisted of external beam radiotherapy (60 Gy) combined with temozolomide chemotherapy (75 mg/m2). After an uneventful clinical course of 14 months, a follow-up MRI in June 2007 showed a nodular and contrast-enhancing lesion at the anterior aspects of the former resection cavity. At subsequent craniotomy, the recurrent lesion could be dissected from cortical tissue circumferentially and gross total resection was achieved. Second-line chemotherapy with bevacizumab and irinotecan was initiated.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 28-year-old woman presented with amenorrhea and blurred vision for 3 years and was admitted to our hospital for further evaluation. MRI of brain was performed and the coronal T2 weighted image revealed a well defined, high signal mass 26 x 22.5 x 21 mm, in the left anterior lobe of the pituitary gland. The pituitary stalk was elevated with of the hypothalamus (Figure 1). Serum prolactin level was 40.4 ng/ml (normal range: 3.0-20.0 ng/ml). The other results were within normal range. The preoperative survey revealed no evidence of other tumor in the body. The patient underwent transsphenoidal adenomectomy.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 29 year-old male with limited health care interactions, previously diagnosed hypertension, and history of tobacco use presented following rapid onset nausea, dizziness, blurry vision, and tremors, resulting in a syncopal episode. At the initial formal assessment, physical examination revealed no specific abnormalities. Specifically, the neurologic examination demonstrated no focal deficits. Laboratory values were within normal limits, and toxicology studies were all negative. A CT scan of the brain revealed a 1.3 cm solitary, ring-enhancing lesion in the right temporal-parietal region, with associated vasogenic edema.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

A 29-year-old man described progressive difficulty climbing stairs over a decade. He did not report any other neurological symptoms including upper limb, bulbar, facial or respiratory muscle weakness. His perinatal history and development were unremarkable, although he had never been particularly good at sport. There was no family history of cardiac or neuromuscular disease. Neurological examination revealed an exaggerated lumbar lordosis and myopathic gait. He had moderate symmetrical, predominantly proximal, limb weakness which was more marked in the lower than the upper limbs and normal tendon reflexes. There was no sensory loss, myotonia or muscle hypertrophy. Serum creatine kinase level was elevated at 1096 IU/L (upper limit of normal: 250 IU/L). Electromyogram was myopathic. Electrocardiogram and echocardiography were normal.

(This case study was added to OER Commons as one of a batch of over 700. It has relevant information which may include medical imagery, lab results, and history where relevant. A link to the final diagnosis can be found at the end of the case study for review. The first paragraph of the case study -- typically, but not always the clinical presentation -- is provided below.)

The patient is a previously healthy 29-year-old man who was admitted to our hospital for evaluation after experiencing seizures. A neurological examination elicited no abnormalities. CT and MR imaging were performed and revealed a cortico-subcortical lesion mass involving most of the right frontal lobe with sulcal effacement, compression on the foramen of Monro and hydrocephalus. The CT demonstrated curvilinear narrow calcifications (Figure 1). The lesion was hyperintense to the cortex on T2 and FLAIR (Figures 2 and 3) while partially hyperintense on T1 (Figure 4), with a marked homogeneous enhancement (Figure 5). All the sequences showed a "bag-of-worms sign" (which is best seen on the T2-weighted images) due to the presence of multiple tiny vessels associated with flow-voids (Figures 2 and 3). Moreover, in the lesion there were two deeply seated pseudocysts that showed contrast enhancement visible in the late phase. Based on these findings, a digital subtraction angiography (DSA) was performed which confirmed the hypervascular nature of the lesion but it did not indicate the presence of an arteriovenous malformation (Figure 6). At surgery, the lesion was removed via a right frontal craniotomy. The excision was macroscopically complete.