Medical Image of the Week: Diffuse Pulmonary Ossification

 

Figure 1. Scout view from a high-resolution CT (HRCT) in this patient, demonstrating predominantly peripheral coarse interstitial thickening, with architectural distortion. Multiple calcific densities are associated with the interstitial abnormality.

Figure 2. A: High resolution CT axial image, 1 mm slice thickness, “lung windows”, bone algorithm. (Window width, 2500 HU; level, 500 H). Extensive peripheral/subpleural predominant reticulation and superimposed net-like, branching, and highly attenuating structures (dendriform configuration) are nicely depicted. Some coexisting less than 4 mm nodules are deposited predominantly in the areas of reticulation. B: Corresponding mediastinal window.

An 84-year-old man with a twelve-year history of interstitial lung disease with indolent course was referred for a new oxygen requirement. He had previously been diagnosed with usual interstitial pneumonia associated with occupational exposures. Over the previous six-months he became breathless with minimal activity. During this interval he had lost nearly 40 pounds. He had worked in uranium mining and had a mere four-pack-year smoking history. In his free time, he was an artisan and engaged in woodworking, metal craft and stonework. He was hypoxic with exertion and notably cachectic. His clinic exam was significant for grade 1 clubbing and soft inspiratory crackles that were audible at the bilateral bases. Pulmonary function testing demonstrated a restrictive ventilatory defect with severe reduction in diffusion capacity. A chest radiograph was followed by high resolution computed tomography (HRCT) with representative images shown in Figures 1 and 2. A diagnosis of diffuse pulmonary ossification (DPO) associated with UIP was made.

Pulmonary ossification indicates bone tissue formation; this in contrast to the deposition of calcium salts in pulmonary calcification. The pathogenesis is uncertain as most patients have no derangements in serum calcium and phosphorus levels. Transforming growth factor-β, implicated in idiopathic pulmonary fibrosis, is also thought to stimulate chondrocytes and osteoblasts in DPO. Other associated chemokines include bone morphogenic protein, and interleukins 1 and 4.

Patients with DPO may be minimally symptomatic or have significant disease to the level of respiratory failure. The diagnosis is most often made by a surgical biopsy or at the time of autopsy. Nodular and dendriform histologic types are described; the latter of which develops in areas of interstitial fibrosis. The nodular form often follows longstanding pulmonary venous congestion from cardiovascular disorders. Chest radiography is insensitive for diagnosis and may only demonstrate an interstitial pattern. Calcification is generally only seen once HRCT is obtained. ^99mTc-methylene diphosphonate (Tc-MDP) nuclear medicine scanning will also detect the presence of pulmonary ossification. Imaging-wise, the differential diagnosis for DPO, is restricted. Pulmonary alveolar microlithiasis could potentially be confused with DPO. The intra-alveolar accumulation of innumerable minute calculi called microliths are generally much smaller, usually less than 2 mm, with a uniform size and distribution throughout the lungs (‘sandpaper” appearance). At a later phase the number and volume of the calcific deposits increases and becomes more granular. The distribution follows the interlobular septa or bronchovascular bundles and can be confused with DPO. Previous granulomatous disease may have a somewhat similar appearance. However, the density per area unit of the calcific deposits tends to be much less, and the distribution is more random and not necessarily associated with underlying abnormal/ fibrosing tissue. There is a strong association between DPO and IPF, when compared with nonspecific interstitial pneumonia (NSIP) and chronic hypersensitivity pneumonitis. This may improve diagnostic specificity in patients with IPF.

Therapy with calcium binding agents, chelation, and corticosteroids has been disappointing, and there is currently no proven treatment.

Steven Sears DO¹, Bhupinder Natt MD¹, and Diana Palacio MD²

¹Division of Pulmonary, Critical Care, Allergy and Sleep and ² Department of Medical Imaging

University of Arizona College of Medicine. Tucson, AZ USA

References

1. Chai JL, Patz EF. CT of the lung: patterns of calcification and other high-attenuation abnormalities. AJR AM J Roegenol. 194;152:1063-6.[CrossRef] [PubMed]
2. Fried ED, Godwin TA. Extensive diffuse pulmonary ossification. Chest. 1992;102:1614-5. [CrossRef] [PubMed]
3. Chan ED, Morales DV, Welsh CH, McDermott MT, Schwarz MI. Calcium deposition with or without bone formation in the lung. Am J Respir Crit Care Med. 2002;165:1654-69. [CrossRef] [PubMed]
4. Schwarz MI, King TE. Interstitial lung disease 3rd ed. Hamilton, Ontario: B.C Decker, 1998.
5. Fernández-Bussy S, Labarca G, Pires Y, Díaz JC, Caviedes I. Dendriform pulmonary ossification. Respir Care. 2015 Apr;60(4):e64-7. [CrossRef] [PubMed]
6. Egashira R, Jacob J, Kokosi MA, Brun AL, Rice A, Nicholson AG, Wells AU, Hansell DM. Diffuse pulmonary ossification in fibrosing interstitial lung diseases: prevalence and associations. Radiology. 2017 Jul;284(1):255-63. [CrossRef] [PubMed]
7. Castellana G, Castellana G, Gentile M, Castellana R, Resta O. Pulmonary alveolar microlithiasis: review of the 1022 cases reported worldwide. Eur Respir Rev. 2015 Dec;24(138):607-20. [CrossRef] [PubMed]

Cite as: Sears S, Natt B, Palacio D. Medical image of the week: diffuse pulmonary ossification. Southwest J Pulm Crit Care. 2019;19(2):65-7. doi: https://doi.org/10.13175/swjpcc028-19 PDF 

Medical Image of the Month: Reexpansion Pulmonary Edema

 

Figure 1. Large right hydrothorax with mild mediastinal shift to the left.

Figure 2. Status post right pleural pigtail drain placement with interval improvement of the now small right pleural effusion with re-expansion of the right lung and early edema.

Figure 3. Moderate right pleural effusion and worsening reexpansion pulmonary edema.

A 54-year-old woman with decompensated alcoholic liver cirrhosis presented to the emergency department with exertional dyspnea. She was afebrile, tachycardic (110), with oxygen saturation of 74% on 5 liters/minute (L/min), in moderate respiratory distress and was subsequently placed on a non-rebreather. On examination, she had absent breath sounds throughout her right lung with chest radiograph revealing large right-sided pleural effusion (Figure 1). A pigtail catheter was placed, draining approximately 4 liters of fluid (Figure 2), resulting in improved oxygenation to 93% on 3 L/min. On admission to internal medicine, the chest tube was clamped immediately. In the next 24 hours, patient developed increased oxygen requirements, with worsening tachypnea and tachycardia, requiring bilevel positive airway pressure and admission to the medical intensive care unit for reexpansion pulmonary edema (Figure 3).

Hepatic hydrothorax is a complication of cirrhosis and portal hypertension, defined as pleural effusion without any underlying pulmonary or cardiac etiologies. Though the pathophysiology is not completely understood, it is widely believed that the pleural effusion is caused by negative intrathoracic pressures allowing peritoneal fluid to enter the pleural cavity through diaphragmatic defects. Management of hepatic hydrothorax includes sodium restriction, diuresis, therapeutic thoracentesis, and transjugular intrahepatic portosystemic shunt. Repeated thoracentesis is the routine procedure to remove pleural fluid in refractory hepatic hydrothorax (1).

Though relatively safe, thoracentesis is associated with reexpansion pulmonary edema (RPE). RPE is believed to occur due to increased permeability of the pulmonary capillaries as a result of inflammation caused by ventilation and reperfusion of previously collapsed lung. Symptoms of RPE include chest discomfort and cough with onset typically within 24 hours of lung reexpansion. Signs of RPE include tachypnea, tachycardia, lung crackles, and hypoxemia refractory to oxygen therapy. Risk factors are young age (20-40 years), long duration of lung collapse, use of negative pressure during thoracentesis, large volume drainage, and rapid lung reexpansion. Management is largely supportive and ranges from diuresis to endotracheal intubation with mechanical ventilation (2).

Unfortunately, the amount of fluid that can be safely removed from the pleural effusion in order to prevent RPE has not been clearly defined. Feller-Kopman (3) reported that only one patient (0.5%) of 185 participants experienced clinical RPE, while four patients (2.2%) had radiographic RPE without symptoms. Our case demonstrates that removal of large volume from the pleural effusion via the chest tube resulted in clinical and radiographic RPE, thus, necessitating the need for clearly defined guidelines.

Chelsea Takamatsu BS, Aida Siyahian MS, Ella Starobinska MD, and Anthony Witten DO

University of Arizona College of Medicine- Tucson

Tucson, AZ USA

References

1. Garbuzenko DV, Arefyev NO. Hepatic hydrothorax: An update and review of the literature. World J Hepatol. 2017 Nov 8;9(31):1197-1204. [CrossRef] [PubMed]
2. Kasmani R, Irani F, Okoli K, Mahajan V. Re-expansion pulmonary edema following thoracentesis. CMAJ. 2010 Dec 14;182(18):2000-2. [CrossRef] [PubMed]
3. Feller-Kopman D, Berkowitz D, Boiselle P, Ernst A. Large-volume thoracentesis and the risk of reexpansion pulmonary edema. Ann Thorac Surg. 2007 Nov;84(5):1656-61. [CrossRef] [PubMed]

Cite as: Takamatsu C, Siyahian A, Starobinska E, Witten A. Medical image of the month: reexpansion pulmonary edema. Southwest J Pulm Crit Care. 2019;19(1):12-4. doi: https://doi.org/10.13175/swjpcc024-19 PDF

Medical Image of the Week: Pulmonary Alveolar Proteinosis

Figure 1. Representative image from an axial CT scan showing “crazy paving”.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease characterized by alveolar accumulation of surfactant (1). It usually results from mutations in surfactant proteins or granulocyte macrophage-colony stimulating factor (GM-CSF) receptor genes. Other causes include toxic inhalation or hematological disorders, or it may be auto-immune, with anti-GM-CSF antibodies blocking activation of alveolar macrophages.

Auto-immune alveolar proteinosis is the most frequent form of PAP, representing 90% of cases. Although not specific, high-resolution computed tomography shows a characteristic diffuse ground-glass attenuation with superimposed interlobular septal thickening and intralobular lines which is called “crazy paving” (Figure 1). In most cases, bronchoalveolar lavage findings establish the diagnosis. Whole lung lavage is the most effective therapy, especially for auto-immune disease. Novel therapies targeting alveolar macrophages (recombinant GM-CSF therapy) or anti-GM-CSF antibodies (rituximab and plasmapheresis) are considered investigational. 

Bhupinder Natt MD FACP

Division of Pulmonary, Allergy, Critical Care and Sleep

Banner University Medical Center, Tucson (AZ) USA

Reference

1. Borie R, Danel C, Debray MP, Taille C, Dombret MC, Aubier M, Epaud R, Crestani B. Pulmonary alveolar proteinosis. Eur Respir Rev. 2011 Jun;20(120):98-107. [CrossRef] [PubMed]

Cite as: Natt B. Medical image of the week: pulmonary alveolar proteinosis. Southwest J Pulm Crit Care. 2018;16(1):14. doi: https://doi.org/10.13175/swjpcc002-18 PDF 

Medical Image of the Week: Type A Aortic Dissection Extending Into Main Coronary Artery

Figure 1. Electrocardiogram at presentation showing ST segment elevation in anterior leads (arrows).

Figure 2. Coronary angiogram showing RAO caudal view of left main coronary artery after contrast injection with the smooth proximal linear irregularity suspicious for dissection flap into the left anterior descending artery (arrow).

Figure 3. Panel A: Computed tomography angiogram transverse view showing true lumen and false lumen of both ascending and descending aorta (arrow). Panel B: Computed tomography angiogram sagittal view showing dissection from root into abdominal aorta. 

A 58-year-old woman with no significant past medical history, presented to the emergency department with complains of sudden onset, severe , non-radiating epigastric pain associated with nausea and vomiting. An electrocardiogram (EKG) done in emergency department showed ST segment elevation in the anterior leads (Figure 1). Blood pressure at presentation was 141/79, and she had symmetrical bilateral pulses of the upper extremities, no diastolic murmur, and no neurologic deficit. The patient was taken to catherization laboratory, for ST segment elevated myocardial infarction (STEMI). She was found have aortic dissection extending to the left main coronary artery (Figure 2). Cardiothoracic surgery was called immediately. Computed tomography angiogram (CTA) of the thoracic and abdominal aorta revealed Debakey type 1 aortic dissection. (Figure 3). The patient was taken to the operating room. Unfortunately, the patient suffered pulseless electrical activity (PEA) arrest during anesthesia induction from which she could not be revived.

Aortic dissection is a critical compromise in the lining of the main arterial outflow from the heart (1).  Two theories have been proposed to explain the pathogenesis. A tear in the tunica intima, of the aorta, leads to blood from the aortic lumen surging into the tunica media (2). In contrast, the second theory holds that the vasa vasorum in the more outer portions of the tunica media hemorrhage first and then cause the rupture of the tunica intima (2). The pressure of the pulsatile blood flow extends the dissection, typically in an anterograde fashion (2). Anatomically aortic dissection is classified as Debakey 1,2, and 3 and Stanford A and B (1). Rarely aortic dissections can also extend in a retrograde fashion to reach the coronary ostia (3). Signs of myocardial ischemia including ST segment changes, adversely affect survival outcomes in patients with type A aortic dissection extending to the coronary arteries (4).

Ali Osama Malik MD¹, Oliver Abela MD², Chowdhury Ahsan MD², and Jimmy Diep MD²

¹Department of Internal Medicine

²Department of Cardiovascular Medicine

University of Nevada School of Medicine

Las Vegas, NV USA

References

1. Golledge J, Eagle KA. Acute aortic dissection. Lancet. 2008 Jul 5;372(9632):55-66. [CrossRef] [PubMed]
2. Patel AY, Eagle KA, Vaishnava P. Acute type B aortic dissection: insights from the International Registry of Acute Aortic Dissection. Ann Cardiothorac Surg. 2014 Jul;3(4):368-74. [CrossRef] [PubMed]
3. Neri E, Toscano T, Papalia U, Frati G, Massetti M, Capannini G, et al. Proximal aortic dissection with coronary malperfusion: presentation, management, and outcome. J Thorac Cardiovasc Surg. 2001 Mar;121(3):552-60. [CrossRef] [PubMed]
4. Imoto K, Uchida K, Karube N, Yasutsune T, Cho T, Kimura K, et al. Risk analysis and improvement of strategies in patients who have acute type A aortic dissection with coronary artery dissection. Eur J Cardiothorac Surg. Sep;44(3):419-24; discussion 24-5. [CrossRef] [PubMed]

Cite as: Malik AO, Abela O, Ahsan C, Diep J. Medical image of the week: type A aortic dissection extending into main coronary artery. Southwest J Pulm Crit Care. 2017;14(5):238-9. doi: https://doi.org/10.13175/swjpcc044-17 PDF