Medical Image of the Week: Complex Arteriovenous Malformation

Figure 1. Initial chest radiograph demonstrating right mid lung field process.

Figure 2. Panel A: Contrast enhanced thoracic CT scan axial view demonstrating very large, complex AVM. Panel B: Sagittal view.

Figure 3. Chest radiograph after coil embolization.

A 62-year-old man presented to the emergency department complaining of shortness of breath with exertion and mild non-productive cough. The patient was afebrile and physical exam was remarkable only for scattered bilateral rhonchi. White blood cell count was 8,800 K/uL and hematocrit was 51.5%. Room air arterial blood gas (at 1520 meters altitude) was pH 7.41, pCO2 42 mm Hg, PO2 45 mm Hg, and O2 saturation 78%. D-dimer was normal at 0.36 ug/ml. Chest radiograph (Figure 1) demonstrated what was interpreted as a right-sided mid/lower lung field infiltrate. The patient was placed on high-flow supplemental oxygen and treatment was initiated with intravenous levofloxacin, methylprednisilone and nebulized beta-agonists. The patient’s oxygenation failed to improve over a period of several days, and a CAT of the chest (Figures 2) was obtained, which demonstrated a very large, right middle lobe, complex pulmonary arteriovenous malformation. The patient was referred to interventional radiology for catheter directed coil embolization (Figure 3). Following that procedure the patient’s oxygen requirement decreased from 15 l/m via nasal cannula to 3 l/m.

Pulmonary arteriovenous malformations (PAVM’s) are rare, with an incidence of 2-3 per 100,000, and are associated with hereditary hemorrhagic telangiectasia (HHT), in approximately 80% of cases (1). The intrapulmonary shunt associated with PAVM’s may result in significant hypoxemia, cerebrovascular accident or embolic brain abscess. The preferred screening tool is transthoracic contrast echocardiography, which demonstrates extra-cardiac shunt. Chest CT scan may be used to both confirm the diagnosis of PAVM and to define the vascular anatomy. Patients who meet three of the four Curacao criteria (epistaxis, family history, telangiectasia, and visceral lesions) are recognized as suffering from HHT (2). Catheter directed coil embolization is an effective and well-tolerated treatment method for PAVM; and generally results in reduced shunt fraction and improved oxygenation (3).

Kathleen Monahan and Charles J. VanHook MD

Longmont United Hospital

Longmont, Colorado USA

References

1. Cartin-Ceba R, Swanson KL, Krowka MJ. Pulmonary arteriovenous malformations. Chest. 2013 Sep;144(3):1033-44. [CrossRef] [PubMed]
2. Shovlin CL, Guttmacher AE, Buscarini E, Faughnan ME, Hyland RH, Westermann CJ, Kjeldsen AD, Plauchu H. Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome). Am J Med Genet. 2000 Mar 6;91(1):66-7. [CrossRef] [PubMed]
3. Dutton JA, Jackson JE, Hughes JM, Whyte MK, Peters AM, Ussov W, Allison DJ.Pulmonary arteriovenous malformations: results of treatment with coil embolization in 53 patients. AJR Am J Roentgenol. 1995 Nov;165(5):1119-25. [CrossRef] [PubMed]

Cite as: Monahan K, VanHook CJ. Medical image of the week: complex arteriovenous malformation. Southwest J Pulm Crit Care. 2016 May;12(5):197-8. doi: http://dx.doi.org/10.13175/swjpcc027-16 PDF

Medical Image of the Week: Achalasia with Lung Abscess

Figure 1. CT coronal view showing a left lower lobe lung abscess measuring approximately 8 x 5 cm.

Figure 2. Barium swallow study showed dilated esophagus with tapering off at the lower esophageal sphincter junction, demonstrating the classic bird-beak like appearance.

Figure 3. Upper endoscopy showing diffuse whitish plaque suggestive of candidiasis likely due to chronic stasis of food.

An 80-year old woman with past medical history of high grade serous fallopian tube carcinoma presented with 2 months history of productive cough. This was associated with shortness of breath and subjective fever, chills and weight loss of 5 pounds over 2 months. She was treated with outpatient antibiotics without improvement of symptoms. Patient was afebrile on presentation, hemodynamically stable, and saturating at 99% on room air. Lung examinations revealed dullness on percussion of left lower lung field and reduced breath sounds on the same area.

Computed tomographic imaging revealed a large lung abscess on left lower lobe (Figure 1) and moderately dilated esophagus and fluid filled to the level of gastro-esophagus junction. Barium swallow study showed a classic bird-beak like appearance (Figure 2). There was no contrast that passed through the gastro-esophagus junction during the entire course of the barium study. Upper endoscopy was performed to rule out intraluminal pathology that may contribute to the obstruction which revealed a large amount of barium and retained food in the entire esophagus with diffuse whitish plaque suggestive of candidiasis and a benign appearing intrinsic mild stenosis at lower third of esophagus (Figure 3). Pneumatic dilation and botulinum toxin injection were performed and she was started on pantoprazole. She was also started on broad-spectrum antibiotics (vancomycin, cefepime, metronidazole) for the lung abscess. A chest tube was inserted under computed tomography (CT) guidance. Subsequently, cultures from the chest tube drainage grew Streptococcus intermedius. She was discharged to a skilled nursing facility with additional 3-weeks of ampicillin-sulbactam. Repeat imaging at 3-weeks showed improvement of the lung abscess.

Achalasia is a rare primary esophageal motor disorder, with incidence of approximately 1 in 100,000 people annually and prevalence of 10 in 100,000 (1). Common presentations of achalasia includes gradual dysphagia to solid and liquids, heartburn symptoms unrelieved by adequate proton pump inhibitor therapy and weight loss. Achalasia presenting with respiratory symptoms without dysphagia is rare as this disease entity is gradual and patient will normally present with different degrees of dysphagia or regurgitation of food. This case report is a good reminder that aspiration should be considered as a cause for pneumonia in the elderly. Our patient could have been aspirating for a period of time, leading to the development of a large lung abscess. Kikuchi et al. (2) demonstrated the high incidence of silent aspiration in the elderly population. A more detailed assessment by trained swallowing therapist may aid in detecting dysphagia.

Kai Rou Tey MD¹ and Naser Mahmoud MD²

¹Department of Internal Medicine University of Arizona College of Medicine- South Campus

²Department of Pulmonary, Critical Care, Allergy and Sleep, University of Arizona College of Medicine

Tucson, AZ USA

References

1. Francis DL, Katzka DA. Achalasia: update on the disease and its treatment. Gastroenterology. 2010 Aug;139(2):369-74. [CrossRef] [PubMed]
2. Kikuchi R, Watabe N, Konno T, Mishina N, Sekizawa K, Sasaki H. High incidence of silent aspiration in elderly patients with community-acquired pneumonia. Am J Respir Crit Care Med. 1994 Jul;150(1):251-3. [CrossRef] [PubMed]

Cite as: Tey KR, Mahmoud N. Medical image of the week: achalasia with lung abscess. Southwest J Pulm Crit Care. 2016 May;12(5):194-6. doi: http://dx.doi.org/10.13175/swjpcc025-16 PDF