(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 41-year-old previously healthy Japanese female presented with a 2-month-history of left occipital headache and dizziness. She had instability in standing on her left foot. A contrast-enhanced T1-weighted MR scan showed a high signal, 4.6 × 3.2 × 3.5 cm extra-axial mass containing a cyst located in the left posterior cranial fossa (Fig. 1a). It attached to the dura mater along the occipital bone and the petrous bone, a part of which was extending into the sigmoid sinus. Catheter angiography illustrated a hypervascular tumor fed by the middle meningeal artery and the ascending pharyngeal artery. The sigmoid sinus was occluded by the tumor invasion.

(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 41 year old gentleman who presented with a 2 week history of right sided "sharp and stabbing" rib pain without history of trauma or injury. The patient stated he felt a "snap" with a burst of pain in the right costal area, followed by inability to walk and could not breathe secondary to pain. His weight and appetite were stable prior to the incident. A chest CT scan revealed expansion of the cortex and medullary cavity of the right posterior 6th rib and a fracture with associated lytic focus in the posterior right 9th rib. The CT scan was interpreted as "hyperplasia/dysplasia" of the right 6th posterior rib and a pathologic fracture of the 9th posterior rib.

(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 1995, at the age of 29, a woman presented with headache and visual disturbances. She was found to have a capillary hemangioblastoma of the brainstem, which was then resected and pathologically confirmed. The diagnosis of von Hippel-Lindau disease was suspected at this time. One year later, she presented with worsening headache, nausea, vertigo, photophobia, and episodes of unresponsiveness. CT and MRI revealed a 4 cm mass in the right cerebellar hemisphere with effacement and displacement of the fourth ventricle. A VP shunt was placed semi-emergently, and two days later she underwent a second craniotomy for tumor resection. The diagnosis of hemangioblastoma was once again confirmed. In 2004, follow-up MRI of the brain and spine revealed multiple brainstem and cervical and thoracic cord lesions consistent with hemangioblastomas. An abdominal scan showed cystic kidneys with bilateral enhancing heterogeneous renal masses, suspicious for malignancy, as well as multiple pancreatic cysts and a paraaortic nodule of possible left adrenal origin; however a bone scan was normal. It is unclear whether or not the patient was treated for the presumed renal cell carcinoma at this time. In 2007, the then 41-year-old patient presented with a three-day history of falls and disequilibrium, progressive quadriparesis and difficulty swallowing. An MRI of the brain was performed. Axial T2 (Figure 1) and contrast enhanced T1-weighted (Figure 2) images showed a partially cystic (thick arrow) enhancing cerebellar mass, dorsal to the fourth ventricle. Extensive T2 hyperintensity was present in the pons, medulla (thin arrows) and middle cerebellar peduncles. Sagittal unenhanced (Figure 3) and contrast enhanced (Figure 4) T1-weighted images showed a markedly enhancing (black arrowhead) solid mass inferior to the fourth ventricle. Nodular leptomeningeal enhancement on the anterior surface of the pons was consistent with a leptomeningeal tumor. The patient underwent a posterior fossa craniotomy with gross total resection of the mass in April 2007.

(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 previously healthy 42-year-old man presented with two weeks of confusion, lethargy, headache, and malaise. He was diagnosed with AIDS three months prior (CD4 count 198 cells/microliter; viral load 87,100 copies/mL) and was on trimethoprim/sulfamethoxazole prophylaxis but had not started highly active antiretroviral therapy. Neurologic exam was notable for a sleepy man lacking orientation to location or date, perseveration on simple phrases and overall paucity of speech, and generalized weakness. He could not stand unassisted. Reflexes were 3+ throughout.

(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 42 year old man with history of asthma, sinusitis and GERD presented to the critical care unit with a 6 day history of worsening headache, nausea, and vomiting. He reported that the symptoms began with a "popping" sensation after a bout of coughing and fever, although he was afebrile on admission. Neurological exam revealed that he was sleepy, but easily arousable and oriented x 3 with a non-focal motor exam. CT scan showed a large right temporal-occipital hyperdense lesion with surrounding edema suggestive of an acute/subacute hemorrhage and a 4-5mm associated midline shift with no evidence of hydrocephalus. On day 2 he developed a 4/5 left sided hemiparesis, dysarthria, and left hemifacial weakness. MRI of brain demonstrated a large right temporal-occipital intraparenchymal hemorrhage, subtle leptomeningeal enhancement, an increased T2 signal of the brainstem especially within the right pons, and a partial thrombosis of the right transverse and sigmoid sinuses. There was no evidence of underlying tumor or vascular malformations. He developed a worsening of the left hemiparesis (2/5) and was started on heparin anticoagulation for a suspected venous infarct, secondary to the venous sinus thrombosis. On hospital day 4 he was noted to be more alert with improvement in his speech. Repeat MRI showed recanalization of the transverse sinus and stable abnormalities in the brainstem and right temporal-occipital lobes. He remained awake, alert, and oriented with some improvement in his hemiparesis. On day 8 he had a sudden neurological decline, became hemodynamically unresponsive and ultimately expired despite aggressive medical management.

(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 42 year old Caucasian male patient with known Hashimoto's thyroiditis presented the first time in 2010 with increased thirst and nocturia. An MRI of the pituitary gland in 2010 showed an enlarged pituitary stalk up to the infundibulum. Endocrinologically, there were normal levels for ACTH, LH, FSH, TSH, PRL, STH as well as for cortisol, testosterone and IGF-1. The clinical diagnosis of diabetes insipidus due to an autoinflammatory hypophysitis with a normal functioning anterior pituitary was made after excluding other reasons (e.g. sarcoidosis). A symptomatic treatment with desmopressin was initiated and regular follow-ups were held.

(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 42-year-old male suffered a witnessed, new-onset generalized tonic-clonic seizure while driving a car, which lead to an accident. In addition to minor injuries, trauma work-up revealed a 3.6 x 2.6 x 3 cm dural-based mass compressing the right middle temporal gyrus. The lesion appeared well-circumscribed, oval in shape, showed moderate patchy contrast enhancement (Fig. 1). In addition, fine T2- and T1-hyperintense rimming was noted, accompanied by mild perifocal edema, and interestingly, homogenous hypointensity on T2-weighted images (Fig. 2). Evidence of calcification was absent on cranial computed tomography (not shown). Calcification was seen within a small (0.7x2.5x1 cm), fusiform lesion with homogenous contrast enhancement localized in the frontal falx, consistent with a meningioma (Fig. 3). The patient subsequently underwent right temporal osteoplastic craniotomy for the temporal lobe lesion. Intraoperatively, the lesion was adherent to the dura and resembled a meningioma with typical meningeal blood supply. After circular incision and coagulation of the dura, the tumor showed a glassy-whitish appearance. The rubber-like, cartilaginous consistency made it impossible to debulk the central components, despite highest volume of the ultrasonic surgical aspirator. Fortunately, the arachnoidal layer was intact throughout and adhesions were minimal. The core of the tumor could be partially resected using a regular scalpel and then the lesion was shelled-out en bloc (Fig. 4). Finally, the surgical result resembled a Simpson grade I resection of a meningioma.

(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 42-year-old white male presented with sudden onset of suprapubic and pelvic discomfort associated with gross hematuria. His vitals were stable on admission. A cystogram demonstrated a bladder of normal size and contour with no intravesical filling defect. Computed tomography (CT) revealed thickened bladder wall with possible infiltrating hematoma and obstruction of the right ureter with hydronephrosis.

(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 42-year-old man was admitted to the neurosurgery department because of paraparesis and sensory deficits of both feet. The CT scan and MRI examination revealed a solitary intramedullary lesion bulging dorsally from the thoracic spine (T4 level) (Figure 1). Spinal angiography revealed the dense vascularity of the lesion, the presence of feeding and draining vessels, as well as intra-lesional shunting. A gross total resection was 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.)

A 42-year-old man presented with three months of progressive proximal weakness, a thirty pound weight loss, and worsening dysphagia for solids. He had been hospitalized two months earlier for respiratory failure requiring intubation and five days of mechanical ventilation. Arterial blood gas on admission revealed a pH of 7.26; pCO2 58.8 torr; bicarbonate 26.2; and pO2 of 57.1 torr. A primary pulmonary etiology was not found, and he improved. During that hospitalization, an electromyogram of the upper extremities was normal. There were chronic neurogenic changes in the lower extremities. Low amplitude, short duration motor unit potentials suggestive of myopathy were noted in the cervical and thoracic paraspinal muscles.

(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 42-year-old previously healthy male with a past medical history significant only for hyperlipidemia presented with weakness, fatigue and edema of the face and extremities. Initial laboratory studies demonstrated anemia (9.8 mg/dL), renal insufficiency (creatinine 2.3 mg/dL), a weak positive ANA of 1:80 with nucleolar pattern, elevated rheumatoid factor, and negative hepatitis B and C serologies. Urine sediment contained a small number of erythrocytes and white blood cells, and granular and hyaline casts. Because of the patient's clinical picture, including moderate anemia, a serologic evaluation for parvovirus B19 was performed, which was positive for both IgG and IgM antibodies. Additionally, because of renal failure, a renal biopsy was 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.)

A 42 year old previously healthy woman presented with an enlarging soft tissue mass in the popliteal fossa of the left posterior knee. The mass had been noticed 4 months prior and recently began to interfere with flexion of the joint. No preceding trauma was noted.

(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 43-year-old woman presented with a six month history of progressive nocturnal nausea and vomiting, resulting in 30 kilograms of weight loss. Subsequently, she developed gradual cognitive decline and a cerebellar syndrome with gait ataxia and nystagmus. MRI showed multifocal lesions localized periventricularly, parenchymal and in the pons on contrast-enhanced T1-weighted images (Figure 1). Examination of cerebrospinal fluid (CSF), whole body positron emission tomography computerized tomography (PET-CT) scan and bone marrow biopsy did not show extra cranial involvement. The differential diagnosis consisted of metastatic melanoma, lymphoma, multiple sclerosis, meningoencephalitis or a granulomatous infection. Stereotactic biopsy of the lesions was 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.)

A previously healthy 43-year-old woman first suffered from headache with dizziness, vomiting, and nausea beginning 5 months before hospital admission. CT scans showed subarachnoid hemorrhage involving the right temporal and occipital lobes, while MRI revealed abnormal signals in the left thalamus and right temporal-occipital lobes. Five months later she suffered from headache, transient unconsciousness and aggravated left upper-limb paralysis. This time, neurological examinations revealed a decrease in power and deep tendon reflexes of the left upper limb. The activated partial thromboplastin time was notably prolonged at 38.8s, while the prothrombin time was normal. Cerebrospinal fluid (CSF) contained 100 erythrocytes /mm3. Neuroimaging revealed infarcts and hemorrhages in bilateral frontal lobes (Fig. 1a) and slit-like complex softening of the right temporal-occipital lobes (Fig. 1b). MRI showed diffuse enhancement in the dural mater and sulci of bilateral frontal-parietal lobes and tentorium (Fig. 1b).MR venography disclosed occlusions in the right transverse and sigmoid sinus, suggesting thrombosis (Fig. 1c). Five days after admission, the patient died and a restricted cranial autopsy was 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.)

A 43-year-old gentleman presented with swelling over scalp for past four months which was initially painless, hard and progressively increasing in size. It became painful in last one month, which was dull aching, intermittent and relieved by medication. There was no history of seizures, weakness, loss of consciousness, trauma, blurring of vision or vomiting. On examination, the vitals were stable with Glasgow coma scale of E4-V5-M6. Bilateral pupils were of normal size with normal reaction. There were no sensory or motor deficits and cerebellar signs were negative. Contrast enhancing MRI showed bone destructive lesion over parietal region. Axial CT showed a lytic lesion of the calvaria in the midline (Fig. 1a). Some expansion of bone with sclerosis was noted. Sagittal and coronal MRI revealed a midline parietal calvarial lesion, indenting the intact underlying dural structures and expanding the overlying galea (Figs. 1b, 1c). With a preoperative diagnosis of midline fronto-parietal calvarial tumor, a midline fronto-parietal craniotomy was performed and near total excision was achieved. Intraoperatively, a firm to hard pinkish tumor was visualized in the calvarium which was adherent to dura and infiltrating through the calvarial bone. Entire tumor with surrounding 1 cm of bony margin was excised. Post-operative period was uneventful.

(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 43 year old man presented 22 years ago with proptosis and reduced visual acuity of the right eye. He was investigated and found to have an orbital tumor which was subsequently biopsied but not resected. He currently presented with decreased visual acuity and impaired right-sided gaze. On imaging, there was a right retro-orbital tumor for which an excision was performed. Intraoperatively, a well-encapsulated tumor within the cystic component containing clear fluid was noted and the relation of this tumor to the nerve could not be clearly ascertained. On histology, the excised specimen revealed a cellular neoplasm consisting of sweeping fascicles of spindle cells with storiform appearance in some areas. Focal ill defined, Verocay body-like palisades were identified. Scattered blood vessels with hyalinised wall were noted. There was no necrosis, significant atypia or mitotic activity. The tumor showed strong staining for S-100 and focal staining for glial fibrillary acidic protein (GFAP) on immunohistochemistry and ultrastructurally, numerous intertwining cell processes were discerned. The findings corroborated a diagnosis of retrobulbar cellular schwannoma, the retrobulbar region being an uncommon location site for this tumor. Important differential diagnoses to be considered include meningioma, glial tumor in view of positive staining for GFAP in cellular schwannoma and malignant peripheral nerve sheath tumor (MPNST) in view of the increased cellularity. While metastases and death have not been described in cellular schwannoma, incompletely resected cellular schwannoma has presented with recurrence. In such a situation, mitotic count significantly correlates with the incidence of tumor recurrence and close follow up is recommended.

(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 43 year old morbidly obese man with chronic back pain, progressively increasing in severity and unresponsive to medical management. A magnetic resonance scan performed at an outside institution revealed a spinal mass at the L4-L5 vertebral level. The patient was referred to UPMC and underwent a laminectomy of the L4 and L5 vertebrae, and upper portion of the sacrum. Intraoperatively, the lesion was described as a "huge sausage-shaped mass approximately 3.5 cm to 4 cm long with all of the nerve roots peripherally draped over the mass." The mass was arising from the filum terminale and the surface appeared to be well-encapsulated. Complete resection of the tumor was achieved. The post-operative diagnosis was recorded as "intradural spinal cord tumor (ependymoma) L4, L5, S1."

(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 43-year-old woman was admitted with headache over a 3 week period. The clinical examination was completely unremarkable. The past medical history included breast cancer three years before presentation with a contralateral relapse another two years later. Treatment consisted of surgical resection, radiotherapy and post-operative chemotherapy with 4 cycles of epirubicine and cyclophosphamide. The relapse was treated by resection, radiotherapy and anti-estrogen therapy. Two years before current admission, acute myeloid leukemia FAB M4 Eo was diagnosed and treated with induction and consolidation chemotherapy according to the German AMLCG protocol with TAD/HAM double-induction and TAD consolidation chemotherapy followed by 4 weekly alternating maintenance chemotherapy.

(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 44 year-old female with familial Mediterranean fever (FMF), compound heterozygote with M680I and V726A mutations in the MEFV gene, on chronic colchicine therapy, cardiomyopathy with a low ejection fraction of 15-20%, and end stage renal disease on peritoneal dialysis was admitted for shortness of breath and syncopal episodes, complicated by pulseless electrical activity cardiac arrest. She otherwise did not have any acute or chronic neurologic symptoms (e.g. headaches, focal neurologic deficits, or seizures). The patient was resuscitated but developed respiratory failure, with suspected pneumonia and/or sepsis and was placed on antibiotics and inotropic agents; she developed a non ST elevation myocardial infarct. She subsequently had two additional episodes of pulseless electrical activity after which she was placed on extra-corporeal membrane oxygenation but without neurologic recovery. Computerized tomography (CT) showed no acute intracranial hemorrhage or mass effect. Given the poor prognosis, life-saving measures were withdrawn, and she expired.

(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 44 year old female who was found to have an incidental heterogeneously enhancing splenic mass on CT scan. A follow up CT scan 2 years later demonstrated a solid appearing splenic mass with peripheral enhancement on the arterial phase and progressive enhancement on the portal venous phase. The size had increased from 1.6 cm to 2.9 cm so a splenectomy was performed.