Giant Intracranial Aneurysm

A 56-year-old woman with hypertension underwent an evaluation for recurrent syncope. On physical examination, the blood pressure and heart rate were normal, with no observed bradycardia or pauses on telemetry, and the respiratory rate and oxygen saturation were normal. The funduscopic examination was normal, with no signs of papilledema. Computed tomographic (CT) angiography of the head showed a partially thrombosed giant paraclinoid aneurysm of the left internal carotid artery, measuring 5 cm in diameter (Panels A and B, arrows). Six years earlier, an aneurysm of the left internal carotid artery (2.2 cm by 1.3 cm) had been diagnosed, but the patient was subsequently lost to follow-up. During the year before the current presentation, increasing forgetfulness, subjective gait instability, headaches, and urinary incontinence had developed. Despite the patient’s reports of occasional dizziness, motor, sensory, cerebellar, gait, and cranial-nerve examinations were normal. The aneurysm was compressing the third and lateral ventricles, resulting in hydrocephalus and ventricular dilatation (Panel C, arrow). The patient underwent placement of a ventriculopleural shunt, with marked improvement in headaches, cognition, and subjective gait stability. On repeat CT, there was complete resolution of the hydrocephalus and decreased ventricular size. The patient is being followed at the aneurysm clinic, where she is being evaluated for endovascular repair of the intracranial aneurysm.

Vishesh Kumar, M.D.
North Shore Medical Center, Salem, MA
vkumar3@partners.org

Christopher S. Ogilvy, M.D.
Massachusetts General Hospital, Boston, MA

Pyogenic Liver Abscess

A 44-year-old man with diabetes mellitus presented to our hospital after 4 days of fever and abdominal pain. The initial evaluation revealed tachycardia (heart rate, 137 beats per minute), hypotension (blood pressure, 81/44 mm Hg), and abdominal discomfort in the right upper quadrant. There was no rebound tenderness. A lesion with heterogeneous radiodensity was noted in the right upper abdomen on chest radiography (Panel A, arrowheads). Computed tomographic imaging revealed an intrahepatic lesion containing gas and fluid (Panel B, arrowheads). A pyogenic liver abscess was suspected. Blood cultures ultimately grew Klebsiella pneumoniae, which can be gas-producing. Diabetes is an important risk factor for this condition. Despite fluid resuscitation and treatment with inotropic agents and antibiotics, the patient’s clinical condition deteriorated, and he died within 48 hours after admission.

Chin-Wei Yu, M.D.
Ching-Hsing Lee, M.D.
Chang Gung Memorial Hospital, Taoyuan, Taiwan

Giant Syphilitic Aortic Aneurysm

A 76-year-old man presented with progressive dyspnea and leg swelling. He had a remote history of syphilis, which had gone untreated until quite recently. Auscultation of the precordium was notable for the diastolic blowing murmur of aortic regurgitation, and there was electrocardiographic evidence of left ventricular hypertrophy. A chest radiograph showed a mediastinal mass with tracheal deviation (Panel A, arrowhead). Contrast-enhanced computed tomography of the chest revealed an aortic aneurysm measuring 11.4 by 11.5 by 18.0 cm (Panel B, axial image, asterisk, and Panel C, sagittal reconstruction image, asterisk), its caliber markedly different from that of the normal descending aorta (Panels B and C, daggers). The patient underwent replacement of the aortic valve and repair of the aneurysm. Findings on pathological examination of the excised tissue were consistent with syphilitic aortitis, a condition in which spirochetal invasion of the aortic adventitia causes an obliterative endarteritis of the vasa vasorum. Blood supply to the aortic wall is impaired, which results in weakening of the tunica media and formation of the aneurysm.

Taufiek Konrad Rajab, M.D., B. Chir.
Robert P. Gallegos, M.D., Ph.D.
Brigham and Women’s Hospital, Boston, MA

Acute Mesenteric Infarction Associated with Atrial Fibrillation

A 75-year-old woman with chronic atrial fibrillation presented to the hospital with a 2-day history of colicky abdominal pain. The physical examination revealed hypoactive bowel sounds and diffuse abdominal tenderness. Laboratory tests showed a white-cell count of 19,400 per cubic millimeter with 92% neutrophils, a blood urea nitrogen level of 42 mg per deciliter (15 mmol per liter), and a serum creatinine level of 3.0 mg per deciliter (267 μmol per liter). Abdominal computed tomography with contrast material showed occlusion of the main trunk of the superior mesenteric artery with mesenteric venous gas (Panel A, reconstructed coronal image, arrow) and pneumatosis intestinalis (arrowhead). Laparotomy revealed ischemic changes with congestion and transluminal necrosis of the small bowel (Panel B) and ascending colon. The superior mesenteric artery is susceptible to embolic occlusion because of its large caliber and narrow take-off angle from the aorta. Although surgical resection of the necrotic bowel is the treatment of choice, the patient and her family opted for conservative treatment. The patient died 3 days later.

Jia-Ming Wang, M.D.
Shih-Chieh Chang, M.D.
National Yang-Ming University Hospital, Yilan City, Taiwan
dtsurga9@yahoo.com.tw

Calcification of the Aorta and Common Iliac Arteries

A 59-year-old man presented with paresthesia and weakness in both legs. Plain radiography of the abdomen showed marked calcification of the wall of the abdominal aorta (Panels A and B, upper arrows) and the common iliac arteries (Panels A and B, lower arrows). These findings were confirmed on computed tomography of the lower abdomen, which showed calcification of the abdominal aorta (Panel C, arrow). The patient’s medical history included remote glomerulonephritis of uncertain cause. He had received 6 years of ambulatory peritoneal dialysis and 11 years of hemodialysis. Six months before his current presentation, he had undergone renal transplantation. Patients with a long-standing history of dialysis therapy often have marked arterial calcification, which is thought to occur with increased frequency in patients with diabetes, dyslipidemia, increased pulse pressure, or disordered mineral metabolism, especially older patients. Aside from attention to mineral metabolism and cardiovascular risk factors, the optimal surveillance and management of vascular calcification in this population remains uncertain.

Kazumasa Sudo, M.D., Ph.D.
Hiroshi Harada, M.D., Ph.D.
Sapporo City General Hospital, Sapporo, Japan
kazumasa.sudo@doc.city.sapporo.jp

Aeurysm of the azygos vein

A 39-year-old man with no notable medical history was being examined because of a transient ischemic attack. On a chest radiograph, a mediastinal mass was detected when the patient was in the supine position (Panel A, arrow) but disappeared when he was standing (Panel B). This finding indicates an aneurysm of the superior mediastinal venous system. Computed tomography with the administration of intravenous contrast material confirmed a large aneurysm of the azygos vein (Panels C and D). Because of the risk of complications, such as venous thrombosis, the aneurysm was surgically removed and the azygos vein ligated. The patient had an uneventful recovery.

Stage I cancer in the right breast, radiation pneumonitis

A 58-year-old woman with a history of stage I cancer in the right breast (T1N0M0, according to the tumor–node–metastasis classification) presented with a 2-week history of shortness of breath and cough. Eight months before presentation, she had undergone lumpectomy and adjuvant radiotherapy to the affected breast. Over a period of 5 weeks, the patient had been treated with a total dose of 50 Gy of radiation over the targeted field, which included breast parenchyma and a portion of the anterior lung, as shown on computed tomography (CT) with superimposed isodose lines (Panel A). The radiotherapy had ended 6 months before presentation. Subsequent CT showed typical features of radiation pneumonitis, which included consolidation in a nonanatomical distribution that did not conform to lobes or bronchopulmonary segments (Panel B). Many air bronchograms are visible with slight dilatation of peripheral bronchi, which often progresses to traction bronchiectasis. Although pneumonitis occurs mainly within the irradiated areas of the lung, it may spread to nonirradiated areas. The patient was given prednisolone at a dose of 100 mg once a day for 3 days, with the dose then slowly reduced, and her symptoms resolved after 5 weeks of treatment (Panel C).

Pneumoparotid

A 13-year-old boy who had recently begun playing the tuba presented with a 2-day history of facial swelling on the left side and pain without fever or ear or nasal discharge. On physical examination, he had swelling of the left cheek with tenderness on palpation. There was no erythema or crepitance. Massage of the parotid gland resulted in expression of foamy secretions from the parotid duct. Computed tomography of the head, neck, and sinuses (Panel A) revealed air in the left parotid gland (arrow) and in the parotid duct (arrowhead). A reconstructed image (Panel B) also revealed air in the parotid gland (arrow) and lateral to the carotid sheath (arrowhead). There was no radiographic evidence of parotitis or involvement of the retropharyngeal space. The serum amylase level was three times the upper limit of the normal range, probably because of parotid injury; all other laboratory measures were normal. The boy received the diagnosis of pneumoparotid associated with playing the tuba; there was no evidence of parotid infection. Conservative management led to resolution of the symptoms within days. Pneumoparotid can arise in wind-instrument players, glassblowers, and persons in whom air under positive pressure in the oral cavity is forced into the parotid ductal system.

Pulmonary Arteriovenous Fistula

A 50-year-old woman presented with mild exercise-induced shortness of breath; she reported being otherwise healthy. Her family history was notable for her mother’s having the Osler–Weber–Rendu syndrome, also called hereditary hemorrhagic telangiectasia. Physical examination revealed a reduced arterial oxygen saturation level (80%) and telangiectasias of the lips and the tongue (Panel A). Chest radiography showed a tubular opacity in the right lower pulmonary lobe (Panel B, left side, white box, and right side [magnified view], arrows). A gadolinium-enhanced four-dimensional magnetic resonance angiogram revealed a complex vascular structure in the right lower lobe immediately posterior to the left atrium. The posterior view (Panel C) revealed an arteriovenous fistula with two feeding arteries (arrows) and one draining vein (arrowhead). Selective pulmonary angiography confirmed this diagnosis, and the feeding arteries were occluded. Subsequently, the patient’s arterial oxygen saturation level returned to normal (98%). The diagnosis of hereditary hemorrhagic telangiectasia was later confirmed by means of genetic examination.

Bilateral Subacute Subdural Hematomas

A 43-year-old man presented to the emergency department with a 2-day history of headache; he reported being otherwise healthy. Four weeks earlier, he had been an unrestrained driver involved in a motor vehicle accident in which he lost consciousness but did not present to a hospital. He reported having no history of coagulopathy, alcohol abuse, or use of antiplatelet or anticoagulant medication. In the emergency department, his clinical course deteriorated over a period of several hours, with worsening headache, nausea, vomiting, and lethargy. Computed tomography (CT) of the brain, performed without the administration of contrast material, revealed a loss of cortical sulci but failed to show a lesion clearly. Magnetic resonance imaging (MRI) (Panels A and B) revealed large bilateral subdural hematomas. The patient underwent successful evacuation of the hematomas through four burr holes (two on each side). He did well postoperatively and was discharged home, neurologically intact, on postoperative day 4. This case shows the occasional difficulty in visualizing subacute subdural hematomas on CT if they are isodense relative to the brain parenchyma. In such cases, MRI can be useful to better visualize the hematoma.