Organizing Pneumonia And Diffuse Alveolar Damage: An Incidental Finding In An Immunocompromised Patient By EBUS-FNA

摘要

Diffuse Alveolar Damage (DAD) is a clinicopathologic syndrome depicting a deposition of intraalveolar red blood cells, fibrin, and hemosiderin-laden macrophages coming from the alveolar capillaries. The causes of DAD originate from injury to the alveolar circulation. The typical computed tomography scan pattern of DAD comprises of diffuse ground glass opacities with or without consolidation. There is no evidence of DAD presenting as a mass in the literature. Endobronchial ultrasound-guided fine needle aspiration (EBUS-FNA) is not a popular method for diagnosis of DAD. This case report is an example of an immunocompromised patient undergoing induction chemotherapy for myelofibrosis transforming into acute myelogenous leukemia presenting with a left upper lobe mass on imaging. The clinical diagnosis was concerning for fungal pneumonia versus less likely malignancy. EBUS-FNA was performed on the left upper lobe mass to reveal groups of reactive looking pneumocytes wrapping around fibrin deposits forming a pseudopapillary architecture with a background of mixed inflammatory cells, necrotic material, histiocytes, giant cells, and occasional clusters of crowded epithelioid cells. The cell block revealed fibrin deposits and collection of histiocytes consistent with DAD and organizing pneumonia. Special stains and immunohistochemistry did not reveal microorganisms. This case report demonstrates EBUS-FNA of a mass-like lesion showed features of DAD and organizing pneumonia in an immunocompromised patient. EBUS-FNA can be used as a non-invasive procedure for diagnosis of DAD and organizing pneumonia. The cytopathologist should be familiar with these features to help improving the diagnostic accuracy.[The material was presented as an abstract at the American Society of Clinical Pathology (ASCP), 2014 Annual Meeting, October 8-10, 2014, Tampa, Florida, United States.] Introduction Diffuse Alveolar Damage (DAD) is a clinicopathologic syndrome depicting a deposition of intraalveolar red blood cells, fibrin, and hemosiderin-laden macrophages coming from the alveolar capillaries. All the causes of Diffuse Alveolar Damage originate from injury to the alveolar circulation. We present a patient who presents with hemoptysis, anemia, hypoxic respiratory failure, and pulmonary infiltrates on x-ray. There are many causes of Diffuse Alveolar Damage, which includes underlying connective tissue disorder, seropositive systemic vasculitides, bland pulmonary hemorrhage, drug injury, coagulation disorders, and infections. Bronchoalveolar Lavage (BAL) is the diagnostic choice for Diffuse Alveolar Damage as it demonstrates progressively hemorrhagic serial samples1. However, the underlying cause is not diagnosed with BAL, but is identified with history, physical examination, laboratory and serologic testing2. The typical computed tomography (CT) scan pattern of DAD demonstrates diffuse ground glass opacities with or without areas of consolidation3. There is no evidence in the literature of DAD presenting as a mass. This case report will demonstrate a case where endobronchial ultrasound-guided fine needle aspiration (EBUS-FNA) of a mass like lesion can be utilized for diagnosis of incidentally found DAD in addition to the underlying cause. Case Report We report a 67 year old male with a history of myelofibrosis with transformation to acute myelogenous leukemia, latent tuberculosis infection, diabetes mellitus, and hypertension who presents to the our institution for induction chemotherapy. Over the course of the hospital stay, the patient developed neutropenic fevers and was found to be blood culture positive for extended-spectrum beta-lactamase producing E. coli. On the 29th day of hospitalization, his fevers recurred resulting in a chest CT scan to be ordered. This scan demonstrated a new left upper lobe mass concerning for a fungal pneumonia versus less likely malignancy (Figure 1). The patient had been sub-therapeutic on Posaconazole up to this point due t