Medical Image of the Week: Azygous Lobe

Figure 1. Chest X-Ray (A) and thoracic CT scan (B) shows the azygos fissure and the ‘tadpole’ appearance (arrow).  Chest CT (C) shows the lateral course of the azygos vein (arrow) and the accessory lobe.

A 59 year old man underwent chest radiography for evaluation of fever and cough. Imaging showed an accessory azygous lobe.  An azygos lobe is found in 1% of anatomic specimens and forms when the right posterior cardinal vein, one of the precursors of the azygos vein, fails to migrate over the apex of the lung (1). Instead, the vein penetrates the lung carrying along pleural layers that entrap a portion of the right upper lobe. The vein appears to run within the lung, but is actually surrounded by both parietal and visceral pleura. The azygos fissure therefore consists of four layers of pleura, two parietal layers and two visceral layers, which wrap around the vein giving the appearance of a tadpole. Apart from an interesting incidental radiological finding, it is of limited clinical importance except that its presence should be recognized during thoracoscopic procedures. This patient was found to have a cavitary lung lesion which was the cause of his symptoms.

Bhupinder Natt MD, Abdulmagid Eddib MD, Dena H’Leureux MD

Department of Pulmonary, Allergy, Critical Care and Sleep Medicine

University of Arizona and the Southern Arizona VA Health Care System

Tucson, AZ 

Reference

Mata J, Cáceres J, Alegret X, Coscojuela P, De Marcos JA. Imaging of the azygos lobe: normal anatomy and variations. AJR Am J Roentgenol. 1991;156(5):931-7. [CrossRef] [PubMed]

Reference as: Natt B, Eddib A, H'Leureux D. Medical image of the week: azygous lobe. Southwest J Pulm Crit Care. 2013;7(6):353-4. doi: http://dx.doi.org/10.13175/swjpcc158-13 PDF

Medical Image of the Week: Hemophagocytic Lymphohistiocytosis (HLH)

Figure 1. Axial (Panel A) and coronal (Panel B) PET-CT Scan Images showing numerous metabolically active pulmonary nodules and mediastinal lymph nodes.

Figure 2. Axial (Panel A) and Sagittal (Panel B) images of the chest CT showing consolidative pulmonary nodules with surrounding ground glass halo and mediastinal lymphadenopathy.

Figure 3. Bone Marrow Biopsy (x1000). Panel A: macrophage engulfing a neutrophil. Panel B: macrophage engulfing erythrocyte debris.

Figure 4. Panel A: Lower power view of the lung biopsy (H&E stain) showing the interface between the neoplastic lymphocytic infiltrate and benign, normal lung. Panel B: high power view showing the neoplastic B-cell lymphoma with sheets of large lymphocytes.

A 41-year-old African American woman with a history of diffuse large B cell lymphoma in remission was admitted to the hospital with severe dyspnea and abdominal pain. Recent imaging revealed extensive pulmonary and liver nodules with significant mediastinal lymphadenopathy (Figures 1 and 2).  She had an extensive outpatient evaluation of these abnormalities including multiple percutaneous and endoscopic biopsies which were nondiagnostic.  She deteriorated clinically and a ferritin level was elevated at 36,284 ng/mL.  Due to the markedly elevated ferritin, a bone marrow biopsy was performed and was normocellular with trilineage hematopoiesis and erythrophagocytosis consistent with hemophagocytic lymphohistiocytosis (HLH, Figure 3).  A VATS guided lung biopsy was performed revealing recurrence of the diffuse large B cell lymphoma (Figure 4).  She started chemotherapy with the E-SHAP (etoposide, methylprednisolone, cytarabine, cisplatin), however, became severely pancytopenic and developed acute respiratory failure, shock and multi-organ failure.  She died despite aggressive care in the intensive care unit.  Patients with HLH often present with sepsis like symptoms and multiorgan failure.  Measurement of serum ferritin level is a critical test in suggesting the diagnosis once infection is excluded.  Early recognition and prompt treatment is essential to preventing fatal outcomes.

Tauseef Afaq Siddiqi, MD¹; Carlos Tafich Rios, MD²; Carlos L Cantu, MD³; James Knepler, MD¹; Linda Snyder, MD¹

¹ Division of Pulmonary, Allergy, Critical Care and Sleep Medicine,

² Department of Medicine,

³ Department of Pathology, The University of Arizona, Tucson, AZ 85724, USA.

References

1. Raschke RA, Garcia-Orr R. Hemophagocytic lymphohistiocytosis: a potentially underrecognized association with systemic inflammatory response syndrome, severe sepsis, and septic shock in adults. Chest. 2011;140(4):933-8. [CrossRef] [PubMed] 
2. Okabe T, Shah G, Mendoza V, Hirani A, Baram M, Marik P. What intensivists need to know about hemophagocytic syndrome: an underrecognized cause of death in adult intensive care units. J Intensive Care Med. 2012;27(1):58-64. [CrossRef] [PubMed]

Reference as: 

Siddiqi TA, Rios CT, Cantu CL, Knepler J, Snyder L. Medical image of the week: hemophagoctyic lymphohistiocytosis (HLH). Southwest J Pulm Crit Care. 2013;7(6):351-2. doi: http://dx.doi.org/10.13175/swjpcc157-13 PDF