(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.)

21-year-old non-diabetic man presented with acute renal failure, approximately 2 weeks following a "sore throat". The patient has a history of HIV and hepatitis. Pertinent laboratory investigations: Creatinine: 4.5 mg/dl, BUN: 65 mg/dl, potassium: 6.0 mEq/ml, ANA: not available, anti-double stranded DNA antibody: negative, ANCA: negative, anti-GBM antibody: negative, ASO antibody: negative, C3: 98 mg/dl, C4: 28 mg/dl, HIV antibody: positive, hepatitis B surface antibody: positive, hepatitis B surface antigen: negative, hepatitis C antibody: negative, rheumatoid factor: negative, SPEP / UPEP: no evidence of a monoclonal immunoglobulin. Urine sediment: contains red blood cells, urine protein: 2.5 gm/24 hrs, Urine toxicology: positive for marijuana and opiates.

(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 21-year old male with a history of intravenous heroin abuse presented to Presbyterian Hospital status post cardiac arrest. The patient was found unconscious by his father with snoring respirations. His father turned to call 911. When he returned from that phone call, he found that his son had stopped breathing. He was found with Seroquel (quetiapine) packets in his room. When paramedics arrived the patient was in asystole.

(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.)

This 21 year-old male had a history of posterior urethral valves and subsequent obstructive uropathy, requiring a single renal transplantation in 1989. He developed chronic allograft nephropathy in 2001 and underwent a second renal transplantation in 2006, with subsequent multiple episodes of rejection. His treatment included Cellcept, Prograf, methylprednisolone, intravenous immunoglobulin and plasmapheresis. He presented to the emergency room complaining of severe headaches, nuchal rigidity, tachycardia and rigors.

(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 22-year old female presented with a five-week history of right retroorbital pain and eyelid swelling. She denied headaches, loss of vision, focal neurological symptoms or ocular symptoms. On exam she had tenderness over right eyebrow and temporal bone. Her past medical history was unremarkable. An ophthalmologist initially saw her and a CT-scan was ordered. The scan showed an orbital bony lesion, which contained a solid component as well as a fluid level without calcifications or a bony matrix (Figure 1). A subsequent MRI revealed a contrast-enhancing lesion eroding the roof of the orbit posterolaterally on the right (Figure 2). Involvement of the inner table of the temporal bone was also demonstrated on MRI. The patient was referred to our center at this time for further evaluation. A CT angiogram was performed to assess the vascularity of the lesion and whether or not any preoperative embolization would be of utility. On the angiogram no vascular abnormalities could be identified intracranially. One month after her initial presentation she successfully underwent a bifrontal craniotomy with resection of the orbito-temporal lesion and placement of a prosthetic right orbital roof.

(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.)

I feel awful.

(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 22-year-old girl presented with convulsive status epilepticus and a previous history of recurrent seizures, myoclonus, ataxia and impaired cognitive functions. Testing revealed severe metabolic acidosis, elevated transaminases and creatine kinase, and respiratory insufficiency. After intubation and ventilation, thiopental was introduced but the patient's condition worsened dramatically with death after a few hours. The parents gave permission for autopsy.

(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 22 year old Saudi Arabian male, who has been living in the United States for three years. He initially presented 2 days prior to admission to the emergency department of an outside hospital with cough, night sweats, anorexia, severe fatigue, and an unintentional 90 lbs weight loss over the 6 months prior to presentation. He is a previous smoker (1 pack/day for 8 years), but quit several months ago due to his chronic cough.

(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.)

A26- year- old male presented with difficulty in walking and shakiness on the right side of the body for 8 to 9 months. The patient also complained of diplopia and progressively decreasing sensation of taste on the right side of the tongue. On neurological examination, the patient was conscious and oriented. There was right upper motor neuron facial nerve palsy. The cerebellar signs were positive. The magnetic resonance imaging (MRI) revealed 4.7x4.6x4.3 cm posterior fossa mass lesion in midline and right cerebellar hemisphere. It was hypointense on T1w and heterogeneously hyperintense on T2w and flair images with areas of blooming on gradient images (calcification / hemorrhage). The mass was compressing the 4th ventricle with upstream hydrocephalus. It involved right inferior cerebellar peduncle and medulla with mass effect on brain stem and a focal hyperintense focus in continuity with the right dorsal medulla. On post-contrast images there was significant enhancement of the lesion (Figure 1). The patient underwent an uneventful midline craniotomy with tumor excision by transvermian approach. The patient was referred for radiotherapy and alive at 6 months postoperatively.

(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 22-year-old man presented with short-term complaints of headache, vomiting and diplopia. On neurological examination, bilateral papilledema and left abducent nerve palsy were seen. Brain Magnetic Resonance Imaging (MRI) disclosed, both in FLAIR and enhanced T1-weighted sequences, a diffuse leptomeningeal enhancement over cerebral and cerebellar hemispheres (Fig. 1), which assumed a nodular-like appearance over the vermis (Fig. 2). No intraparenchymal mass was elicited. A lumbar puncture of cerebrospinal fluid (CSF) showed an opening pressure of 360 cm H2O, and the CSF chemistry, low glucose level (1.1 mg/dl) and normal protein and cell count. CSF cytological analysis, viral serology and cultures were negative. No abnormalities were found in Angiotensin-Converting Enzyme (ACE), beta-2 microglobulin, alpha-fetoprotein (AFP) and PCR levels. The patient was started on corticotherapy with significant neurological improvement, but after discontinuing steroids, headache and visual complaints renewed, and new-onset gait disturbance and impaired sensibility over the perineum and left foot were noticed. Fifth, sixth and seventh cranial nerve palsies, gait ataxia, and perineal pinprick hypoesthesia with a saddle distribution were then elicited. An enhanced MR imaging of the spine revealed a leptomeningeal enhancement of cervical and lower dorsal segments, down to the conus medullaris and cauda equine. Again, CSF cytology was unremarkable. Also, the neuropathological examination of a small fragment of the left cerebellar hemisphere, obtained by stereotactic biopsy, was considered normal. Extensive imaging studies failed to identify a systemic neoplasm. Shortly after discharge, the patient came back with bilateral amaurosis. A brain computer tomography (CT) disclosed a marked hydrocephalus and a ventriculoperitoneal shunt was then performed. This time, CSF cytology was abnormal, and a second cerebellar stereotactic biopsy, this time of the vermis, was undertaken.

(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 23 year old male with a history of Crohn's disease and primary sclerosing cholangitis since age 15. In 2003 he received a living donor liver, which had to be replaced with an orthotopic liver 10 days after transplant due to complications. Over the previous month, his liver enzymes had been trending upwards, worrisome for return of primary liver disease, versus possible stricture at the biliary-enteric anastomosis. Aside from mild generalized jaundice, no discrete worrisome skin lesions were noted. He complained of abdominal and back pain, the latter believed to be a mild inflammation of spinal joints. An upper endoscopy was performed, and significant findings included a patent anastomosis, evidence of portal hypertension in the stomach, and an erythematous proximal jejunum, which was biopsied. Of note, his pre-operative labs showed a microcytic anemia (hemoglobin 10.5 g/dL and MCV 73.9 fL) with an expanded red cell width of 19.5%, which was being treated with oral iron supplementation.

(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 23-year-old male with no significant past history, presented with a tonic-clonic generalized seizure. Physical and neurological examinations were normal. MRI of the brain showed a superficial cystic mass with a mural nodule in the right frontoparietal lobe. Patient underwent right frontal craniotomy with total resection of the tumor. The post-operative course 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.)

The patient is a 23 year-old male who was diagnosed with Wegner's granulomatosis and renal failure previously. The patient was being treated with Cytoxan and corticosteroids. Four months later, the patient developed a lung infection and was started on trimethoprim-sulfamethoxazole. He underwent a video-assisted thoracoscopy to drain a left pleural effusion. Shortly thereafter, he developed pain in his left knee. The patient underwent debridement of the left knee and a sample of synovial fluid was sent to the UPMC Microbiology lab for Gram stain and culture. A picture of the Gram stain is shown in figure 1. Cultures grew the same organism. The patient continued with antibiotic treatment at an outside hospital.

(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 24-year-old Caucasian man was admitted following a 10-day history of severe headache leading to collapse on the street. On presentation, he was confused and agitated with left-sided weakness and a positive left Babinski sign. His medical history was significant for asthma and non-Hodgkin's lymphoma 10 years previously treated with chemotherapy and radiation therapy with no recurrence.

(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 24-year-old man presented with new onset of generalized tonic clonic seizure. Prior to admission, the patient reported an enlarging painless scalp mass for the previous two months, without having sought medical attention. MRI of the brain revealed a 7.7 cm heterogeneously enhancing mass with a large subgaleal extracalvarial/extracranial component and a smaller intracranial enhancing component along the dura on T1 weighted images (Figures 1 and 2). Noncontrast CT showed abnormal calvarial sclerosis concerning for osseous involvement (Figure 3). The patient underwent biparietal craniectomy and sub-total resection of the mass with residual tumor involving the superior sagittal sinus. The cranium, dura, and subgaleal mass were submitted for evaluation.

(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 mother of this fetus was a 24 year old G1 P0 woman with multiple medical problems. These include cerebral palsy, mixed hearing loss, a history of seizures, history of a heart murmur, surgery for cleft lip, and asthma. The current pregnancy was without complications through the first two trimesters. An 18 week anatomy scan was unremarkable. A fetal echocardiogram at 18 weeks was also unremarkable. Early in the third trimester, a clinical concern for size less than dates arose. An ultrasound at 30 weeks found an enlarged fetal heart. No evidence of hydrops was identified, however. On a routine clinic visit at 32 2/7 weeks gestation, the mother complained of no fetal movement for the previous two days. A bedside ultrasound confirmed an intrauterine fetal demise. Labor was induced, with delivery of the stillborn female fetus.

(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 24-year-old white female patient presented to the emergency room with back pain. The pain, which had been ongoing for the past four days, started in her lower back and wrapped around her left leg down below the knee. It was constant and worsened with any activity. Bladder and bowel function were unaffected. The patient denied any prior history of back pain or back injury. She did not have any history of trauma. On physical examination, no focal neurological findings were 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.)

The rapid HIV Multispot test was performed and detests antibody to HIV-1 and HIV-2. The test was read as "preliminary positive" for antibody to HIV-1 according to the manufacturer's guidelines, which state that, "Note: The appearance of any purple color in any of the Test Spots, regardless of intensity, must be considered as presence of that Spot."

(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 reports past medical history of nephrolithiasis only. The patient denies prior surgical procedures. She denies family history of colon, uterine, breast and ovarian carcinomas. Relevant obstetric-gynecological history consists of G3P2012, two full term spontaneous vaginal deliveries. The patient has no history of sexually transmitted infectious diseases and is currently sexually active, taking oral contraceptive pills. No history of abnormal cervical PAP smears.

(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 24-year-old woman with a 3 year history of multiple sclerosis, for which she was treated with beta interferon, was found to have a T2 intermediate mass (1.3 cm x 0.7 cm) within the left internal auditory canal (Fig. 1) in a follow up MRI. There was no associated mass effect on the adjacent brain parenchyma. In addition, there were numerous T2 hyperintense lesions throughout the supratentorial white matter, consistent with the known history of multiple sclerosis. At the time, she did not have any related symptoms; there was no reported abnormality of hearing or balance, and no facial nerve dysfunction. On examination, visual fields and acuity were normal and cranial nerves II through XII were intact, with normal hearing on both sides. Motor-sensory skills 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.)

A 24 year-old white right handed woman with an otherwise unremarkable medical and family history was admitted with vertigo, hiccups, intractable vomiting, gait unsteadiness and oscillopsia that developed gradually over 9 months. Although initially relapsing and remitting, her manifestations became persistent approximately one month prior to her admission. Neurological examination revealed periodic alternating nystagmus, gait ataxia and bilaterally brisk tendon reflexes in upper and lower extremities and a right extensor plantar reflex. On admission brain MRI there were several lesions with increased T2/FLAIR (Fig. 1BCD) and low T1 signal including a space-occupying lesion in the left half of the pons, extending into the left middle cerebellar peduncle, the medulla and the lower mesencephalic tectum (Fig.1A). Lesions did not exhibit gadolinium enhancement (Fig.1A) but showed restricted diffusion in diffusion-weighted sequences (Fig.1E). Spinal cord MRI was normal. CSF analysis on admission and two months later showed normal cell counts and glucose levels, increased protein (83mg/dL and 90mg/dL, respectively), normal IgG index and no oligoclonal bands. CSF flow cytometric analysis was within normal values and CSF cytology was negative for neoplastic cells in both occasions. Full blood counts, biochemistry, serum LDH, thyroid studies, coagulation profiles, ESR, CRP, autoimmune antibody screening including anti-AQP IV antibodies, plasma folate and B12 vitamin levels, plasma protein immunoelectrophoresis, complement levels, urine analysis and serology for hepatitis and HIV were normal. Bone marrow biopsy and contrast-enhanced whole body CT, upper and lower endoscopy and abdominal ultrasonography were unremarkable. Fundoscopy and slit-lamp examination were also unremarkable. Upon magnetic resonance spectroscopy findings suggestive of tumefactive demyelinating lesions, the patient was treated with two monthly courses of mitoxantrone with no apparent clinical benefit and expansion of lesions on MRI, yet still without gadolinium enhancement. A month after the second course of mitoxantrone she developed dysphagia, voice hoarseness and cachexia. Neurological examination revealed left abducens palsy, pathological left-sided cerebellar tests in addition to previous findings and posterior laryngoscopy showed left vocal cord paresis. A new CSF analysis revealed a raised protein level (130mg/dL) with normal cell counts and glucose. CSF cytology, oligoclonal bands were negative and flow cytometric analysis was within normal ranges. A new brain MRI indicated enlargement of pre-existing lesions with peripheral gadolinium enhancement of the brainstem space-occupying lesion (Fig.1F). Stereotactic biopsy of the brainstem lesion was performed.