(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 man was hospitalized with an acute onset of giddiness, drunken gait and tendency to fall. He was apparently well until one week prior to presentation. He experienced these symptoms after drinking heavily at a party. There was no history of trauma, headache, vomiting or seizures.

(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 referred to the neurosurgeon in October 2015, complaining polyuria, polydipsia and polyphagia, associated with violent headache, unresponsive to anti-inflammatory therapy, vomit and loss of consciousness. After the onset of visual impairment in the left eye, the patient underwent MRI scan that revealed a giant irregular suprasellar mass (max diam 3.5 cm) moving from the level of the infundibular area within the third ventricle chamber; these lesion showed (Fig. 1A) strong and in-homogenous enhancement post-GAD and little calcified spots were noted within its bulk. Pituitary hormonal levels were within the normal range. In May 2016 the patient underwent surgery, by mean of endoscopic endonasal approach: at this time, due to the hard consistency, the tight adherences of the tumor and the narrow and deep corridor lesion has been only partially removed. As per protocol a second transcranial approach was scheduled, nevertheless three months later, hydrocephalus developed and urgent ventricle-peritoneal shunt procedure was required, although residual tumor was stable. Six months thereafter a new MRI disclosed a slight enlargement of tumor (volume increase was 30% more than the prior exam), so that transcranial transcortical-transventricular approach was adopted to remove the lesion. Extent of removal at that time was near-total (>90%), nevertheless, patient died few weeks later due to severe meningitis that complicated with multi-organ failure.

(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 45-year-old woman presented to our institution with progressive upper and lower extremity proximal weakness of a few weeks' duration. 3 months prior, the patient received a diagnosis of systemic lupus erythematosus and started on hydroxychloroquine; she had been treated with low dose prednisone for her weakness for the last 3 weeks. Physical examination showed severe proximal weakness, grade 2/5, in the bilateral upper and lower extremities with retained strength in all other muscle groups. The patient had an erythematous rash on her face, chest, and upper back. There was no clinical evidence of involvement of other organs.

(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 45-year-old man presented with left-sided hemihypesthesia, which remitted spontaneously within two months. 18 months later the same symptoms appeared again but were now aggravated by hemiparesis, dysarthria, ataxia and neurogenic bladder dysfunction, which finally led to pyelonephritis and acute renal failure. The patient's past medical, surgical and family history were all non-contributory. Cerebrospinal fluid (CSF) showed normal cell counts, glucose, protein, IgG index and no oligoclonal bands. Cytology was negative for malignant cells.

(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 1999, at the age of 41 this man developed focal seizures in his right arm. The neurological examination was otherwise normal. He was in good health and his medical history was devoid of underlying disease. Cranial MRI revealed a homogeneously contrast enhancing lesion with microcalcifications in the left frontal lobe (Figs. 1 and 2). One year later the patient decided to have stereotactic biopsy. Surgically induced artifacts and small sample size aggravated tumor classification at that time. Differential diagnoses included oligodendroglioma WHO II and diffuse astrocytoma WHO II. In January 2003, at the age of 45, the patients developed weakness in his right arm and seizure frequency increased despite medication. Tumor size had considerably increased. Surgery was offered and the patient decided to have the lesion removed through a left frontal craniotomy. The postoperative course, was unremarkable, the weakness of the right arm disappeared.

(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 45 year old man presented to the emergency room with a history of a small quarter - sized midline tongue lesion present since childhood, which had recently increased in size to that of a golf ball and was associated with spontaneous drainage of a dark brown fluid. There was no mucosal ulceration, or history of dyspnea, odynophagia or bleeding.

(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 45-year-old man presented to us with headache and vomiting for15 years ago. He was diagnosed as having obstructive hydrocephalus due to a pineal region tumour. A ventriculoperitoneal shunt was inserted to relieve hydrocephalus with symptomatic relief. He was followed up with regular MRI scans. Serial imaging showed slow progression in tumor size when he was 60 years old. Neurological examination revealed Parinaud sign with upward gaze palsy. The MRI with gadolinium showed an mildly enhancing lobulated tumor in the region of the superior tectum measuring 22.5mm x 21mm x 20mm (Figs. 1 and 2). The lesion at the superior tectum and the pineal region showed heterogeneous T1-hyperintense signal on precontrast images (Fig. 1). It exhibited very slow growth, with a gradual increase in size over 15 years. There was mild mass effect to the cerebral aqueduct with indentation of the pineal gland (Fig. 3). However, there was no hydrocephalus at that time. In view of symptomatic progression of tumor size, he underwent a near total tumour excision via infratentorial supracerebellar approach.

(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 46-year-old woman was admitted to our hospital with chief complaint of numbness of right lower limb lasting 1 year as well as left leg ache lasting 5 months. The symptoms were gradually developing. There was no history of trauma, drug use or any physical exertion. Neurological examination confirmed sense of pain and temperature subsided in left upper limb, left side of body and right lower limb. Radiating pain happened at the left lap and rear waist, and the tendon reflex weakened slightly at left upper limb and right lower limb. A spinal MRI revealed a heterogeneous intensity enhancing 3.0×1.0×1.0cm mass involving T5 through T7 (Figure 1a, b); it was hypointense on T1 (Figure 1c) and hyperintense on T2-weighted sequences (Figure 1d). Short time inversion recovery (STIR) image showed minimal perilesional edema (Figure 1e). The patient subsequently underwent a near total tumour excision via T5-T7 laminectomy approach. Then she underwent craniospinal irradiation and temozolomide chemotherapy. Postoperative follow-up was uneventful with good control in 12 months.

(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 46 year old female being evaluated for bariatric surgery. During an endoscopy procedure, a raised, "yellowish" nodule (size not specified) was identified at the mid esophagus, 30 cm from the incisors (image 1). An endoscopic mucosal resection (EMR) was performed. Grossly the lesion was described as a 0.6 x 0.4 cm yellow-red, ulcerated and centrally loculated lesion (image 2). H&E images of the EMR specimen are provided in images 3, 4, 5 and 6. PASD staining is shown in images 7 and 8. Immunohistochemistry is shown for S100 is in image 9 and inhibin in image 10.

(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 46 year old white female presented to the endocrine clinic for followup on hypothyroidism and a palpable thyroid nodule. Ultrasound of her thyroid on 09/02/03, revealed multiple nodules including a nodule in the upper right pole measuring 7 x 9mm, a nodule in the left aspect of the isthmus measuring 9 x 4mm (Figure 1), and a nodule in the mid pole of the right thyroid measuring 5 x 5mm. An ultrasound guided fine needle aspiration was performed on the nodule near the isthmus which showed papillary carcinoma. A total thyroidectomy with central lymph node dissection was performed on 09/26/XX which showed papillary carcinoma with one positive lymph node, T1N1MX.

(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.)

Patient is a 46-year-old female with no significant past medical history. She presented to an outside hospital with a three day history of shortness of breath and palpitations. A chest x-ray revealed bilateral lung infiltrates. She was subsequently intubated for respiratory failure and sedated. She also had black, tarry stools and bloody orogastric tube output, and was subsequently admitted to an outside hospital intensive care unit for sepsis. Reported initial complete blood count values included a hemoglobin value of 7.4 gm/dl, platelet count of 13x10E+9/L, and white blood cell count of 10.3x10E+9/L, The peripheral blood differential reportedly demonstrated 15% blasts. She was transferred to the intensive care unit at UPMC for further management. A bone marrow biopsy was performed for further 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.)

A 46-year-old man presented with a 2 week history of bilateral lower extremity numbness and tingling. The patient had a past medical history significant for a right posterior fossa medulloblastoma diagnosed at the age of 24, treated with total resection and craniospinal radiation (5040 cGy to the posterior fossa, 3960 cGy to the whole brain, and 3420 cGy to the spine). Twenty-one years later, at the age of 45, the patient experienced progressive right lower extremity weakness and subsequent MRI showed an expansile intradural extramedullary enhancing 1.3 cm T5 level spinal cord lesion. This lesion was presumed to be recurrent medulloblastoma in the form of drop metastasis, and the patient underwent additional radiation to the tumor and a small surrounding margin (3750 cGy). Several months after treatment, at the age of 46, the patient experienced recurrent symptoms of lower leg weakness. A follow-up MRI revealed a 1.4 cm intradural extramedullary lesion at T7 with associated cord edema. Sagittal sequences performed after the administration of intravenous gadolinium chelate demonstrated subtle enhancement (Figure 1). In an effort to confirm the diagnosis of recurrent meduloblastoma and rule out radiation necrosis or a second malignancy as well as to help determine future treatment it was determined that histological confirmation was necessary. The patient underwent an uneventful thoracic laminectomy at T6-T7 with subtotal resection of the intradural lesion.

(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 39-year-old man was admitted in 2009 following epileptic seizure associated with visual impairment. MRI revealed an expansive and infiltrative lesion in the right parieto-occipital lobe with a cortico-subcortical localization. This lesion was hypointense in T1-weighted images and showed no contrast enhancement after gadolinium injection. Methionine-positron emission tomography (MET-PET) revealed high methionine uptake in this lesion. Partial surgical resection of the lesion was performed. No adjuvant therapy was administered at this moment. MRI images showed progression of the lesion in 2014 but the patient refused surgical intervention and other therapies. In 2017, following painful headache associated with neurological deficit, the MRI suggested progressive neoplasm in the right parieto-occipital lobe (Figure 1) with areas of enhancement on post contrast MRI. MET-PET revealed heterogeneous increased metabolic uptake, suggesting progression of the disease. New surgery 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.)

Patient is a 47 year old female who presented to an outpatient clinic with the chief compliant of thigh swelling due to what was thought to be a blood clot. She received a MRI scan which showed an incidental mass in the contralateral thigh. A more thorough MRI confirmed the 7cm heterogenous lesion in her left vastus intermedius. At this point of time, it was felt to be a sarcoma and a 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 47-year-old male patient presented with a fluctuating hearing impairment in his left ear over the past 5 years. Tinnitus or vertigo was not observed. Audiometric analysis showed an inner ear deficit of 50 dB between 1500 and 6000 kHz on the left side. Hearing in the right ear was normal. The facial nerve was clinically and by means of electrophysiological testing without pathological findings. BEAP (brainstem evoked auditory potentials) revealed a latency increase between J1 and J3 up to 2.5 ms for the left side, whereas only 2.3 ms on the right side. MRI (magnetic resonance imaging) scanning showed a tumor of the cerebellopontine angle in the left inner auditory canal (IAC) of 1.2 x 0.7 x 0.9 cm in size (Figure 1). After application of contrast media, the tumor showed clear signal enhancement. The tumor was entirely removed by a transtemporal approach to the IAC. Surgical exploration found the cochlear nerve embedded in a tumorous mass, whereas the vestibular and the facial nerve were normal (Figure 2, vestibular nerve arrow A and cochlear nerve with tumor arrow B). Nerve and tumor (Figure 3) were removed and sent to histopathological examination. The patient lost his hearing after the operation due to the removal of the cochlear nerve, whereas a regular postoperative vestibular function was observed. The postoperative course as well as the 5-year follow-up examination was unremarkable and control MRI scanning showed 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 47 year-old man presented with left extremity weakness for 1 year, which had worsened significantly over the past 40 days. 23 years ago he suffered head trauma with loss of consciousness for 30 minutes and was diagnosed with a concussion. Two weeks later he had his first generalized seizure, and continued to have about one seizure per week. His seizures were not well-controlled on phenytoin. Fifteen years ago, the patient underwent brain CT scan, revealing right frontal encephalomalacia (Figure 3). Epilepsy surgery was performed and silver clips were deployed for hemostasis. Following the surgery and change of medications to carbamazepine he continued to suffer seizures about one or twice a month. At this current presentation for left extremity weakness, the neurological examination discovered decreased muscle strength of the left side. CT scan revealed a huge hypodense lesion in the right frontal lobe with remarkable mass effect (Figure 1), but without distinct contrast-enhancement (Figure 2). Hyperdense foci could be seen within the mass, which were ascertained to be the silver clips used in his surgery. MRI scan could not be performed due to these clips. A right frontal craniotomy was performed and a large tumor was removed and submitted for pathology.

(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 47-year-old white, right-handed man presented with abrupt onset of left leg numbness while he was at work. He walked around to try to restore circulation when it suddenly became paralyzed and noticed his left arm and leg began to contract rhythmically and involuntarily. There was no report of eye deviation, face involvement, or loss of consciousness. At the time of arrival to the hospital, the movements had stopped. He had no prior history of seizure or stroke. His past medical history was significant for migraine headaches, sinus allergies, chronic uveitis and a history of parathyroidectomy in the past. He had an episode of severe uveitis at age eight with bilateral eye redness and soreness and was treated with steroids and Cytoxan. His medications were oxymetazoline nasal spray for nasal congestion and daily prednisolone eyedrops. He has a 20-year history of tobacco use and drinks alcohol socially. He denied any unusual exposure history and to his knowledge had never been exposed to tuberculosis. His family history was notable for a mother with breast cancer, and sister with Sjögren's syndrome who had uveitis as well.

(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 47-year-old woman was admitted to the hospital with a 4-month history of frontal headache that had radiated to her neck. Physical and neurological examinations did not demonstrate any abnormalities.

(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 48-year-old white female had a history of an appendectomy and hysterectomy for uterine fibroids. She developed persistent fevers and fatigue, loss of appetite and a 20-pound weight loss over approximately 3 months. On admission to an outside hospital, she was pancytopenic and a computerized tomography scan revealed hepatosplenomegaly. She had persistent fevers but a thorough infectious disease and rheumatologic work up was negative. Liver biopsy showed minimal fibrosis. The patient was transferred to a referral hospital. On admission, she was febrile and tachycardic, with jaundice and a mildly distended abdomen with tenderness in the upper quadrants. No palpable lymphadenopathy was noted. She had anemia (hemoglobin 9 g/dl) and thrombocytopenia (platelets 32,000/cu mm). Liver enzymes were mildly elevated but bilirubin was normal. Computerized tomography showed hepatosplenomegaly and anasarca.

(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 48 year old Caucasian male with a past medical history of hypertension, gastroesophageal reflux disease, irritable bowel syndrome, chronic headaches, anxiety, depression, chronic low back pain secondary to spinal stenosis status post L3 through L5 laminectomies in 2009, and end-stage osteoarthritis in bilateral hips status post total left hip (March) and total right hip (September) arthroplasties with metal-on-metal prostheses in 2008. The patient worked in the construction industry for many years and performed daily tasks that resulted in his chronic hip disease, including heavy lifting and prolonged kneeling. Following the left hip replacement, his pain was vastly improved and he did well with no complications. However, following the right hip replacement, he noted increased bilateral hip pain, right more than left. In April 2012, he presented to an outpatient clinic with these complaints, in addition to complaints of increasing confusion, headaches, blurry vision for about two weeks, and short-term memory loss. Radiologic imaging was performed at that time, but failed to reveal signs of joint failure. Interestingly, a blood cobalt level was drawn and returned 11.4 µg/L (reference range: <1.8 µg/L). He subsequently underwent a revision of the right hip in October 2012, replacing the metal-on-metal joint with a non-metal surface prosthesis. A repeat blood cobalt level was drawn after the surgery and returned 5 µg/L. He remained clinically stable following the right hip revision, but in February 2013 he presented to an outside hospital after he sustained a traumatic fall in his basement. He attributed the fall to symptoms of progressive cognitive decline, including confusion, lethargy, short-term memory loss, and depression, which he noted had worsened since his hip procedures in 2008. Computed tomography (CT) and magnetic resonance imaging (MRI) scans of the head did not reveal significant acute pathology, an electroencephalogram (EEG) was also negative for seizure-like activity or any other pathologic activity in the brain, and all other work-ups were essentially negative. On admission to the hospital, he stated that he had a history of elevated blood cobalt levels, but the patient's previous laboratory studies were not available for review by his clinicians. A repeat blood cobalt level was drawn during his hospitalization and returned 3.1 µg/L. The patient was eventually discharged from the hospital with follow-up at an outpatient toxicology clinic for further evaluation.