SESSION TITLE: Bronchology/Interventional Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Inflammatory myofibroblastic tumor is a rare neoplasm that has been described to occur in numerous organs. It is often asymptomatic in the lungs but can present with hemoptysis, dyspnea or cough. Complete surgical resection is the treatment of choice with little evidence for adjuvant chemotherapy or radiotherapy in selected patients. In this case report, we report an endobronchial inflammatory myofibroblastic tumor that occluded the right mainstem bronchus mimicking asthma.
CASE PRESENTATION: 41-year old woman with past medical history of diabetes, hypertension and newly diagnosed asthma was admitted for chest tightness and difficulty breathing. The patient reported acute worsening of her breathing over two weeks and did not resolve with albuterol. Patient’s medications included labetalol, albuterol and insulin. She had c-section and cholecystectomy in the past. She was a former smoker (< 5 pack years), drank socially and denied using any illicit drugs. She had no known allergies. On physical examination, she was not in acute distress. Her temperature was 97F, heart rate of 52 beats per minute, blood pressure of 116/73 mmHg, respiratory rate of 16 breath-per-minute and oxygen saturation of 99% on room air. No lymphadenopathy or JVD was noted. Patient had bilateral expiratory wheezing on lung auscultation. Patient had symmetric expansion of chest wall bilateral. Cardiac sounds were normal S1 & S 2. No neurologic deficits were observed. Initial laboratory showed WBC of 8.0 K/uL, Hbg of 10.6 mg/dL and platelets of 260 K/uL. On chemistries, patient had mildly elevated creatinine at 1.1 mg/dL and serum glucose of 258 mg/dL. A chest x-ray showed a midline trachea with patent left mainstem bronchus. Right mainstem bronchus could not be appreciated. No other significant lung findings were noted on chest xray (Image 1). A CT chest without contrast visualized the right mainstem lesion that occupied the entire right main stem bronchus, extended 1 cm above the carina and air trapping of the right lung (Image 2). Patient subsequently underwent a right thoracotomy with extensive mediastinal lymph node dissection. A bronchial resection and modified sleeve resection with bronchoplasty were performed. The tumor was removed via flexible bronchoscope and specimens were sent for pathology. (Image 3,4) Immunostaining showed polyclonal plasma cells expressing IgG with rare IgG4 positivity. Cells also stained for smooth muscle actin but negative for ALK-1 or desmin. Acid-fast bacilli, GMS, and mucicarmine stains were negative. EBER was negative for EBV. Inflammatory myofibroblastic tumor (IMT) was the final diagnosis. (Image 5-8)
DISCUSSION: Inflammatory myofibroblastic tumor (IMT) of the lung is a rare tumor presenting usually as a single, lower-lobed, well-defined lesion on radiographic imaging. Most pulmonary nodules present peripherally but can occur more centrally and in some instances, affect the bronchus. Patients are often asymptomatic but can present with hemoptysis, dyspnea or cough. Although the etiology of IMTs is unclear, there is evidence to suggest different processes leading to this condition. In younger patients with IMT, ALK gene abnormalities are frequently found suggestive of a neoplastic origin. Older patients are more often found to have IgG4-related disease, as in our patient, suggestive of an autoimmune origin. ALK mutation is associated with local recurrence but not distant metastasis while those without ALK were more likely to present with distant metastasis. Regardless of the pathophysiology of IMTs, surgical resection with clean margins is the mainstay of treatment with 5-year and 10-year survival of 91% and 77% respectively.
CONCLUSIONS: In conclusion, IMT is a rare benign tumor usually seen in children and young adults. It can mimic symptoms of asthma that does not respond to treatment. In our patient, surgical resection was performed with no recurrence to date.
Reference #1: Melloni et al. Inflammatory pseudotumor of lung. Ann Thorac Surg. 2005; 79:426-432
Reference #2: Coffin CM, et al. Am J Surg Pathol 2007; 31:509-520
Reference #3: Cerfolio RJ. et al. Inflammatory pseudotumor. Ann Thorac Surg 1999;67:933-936
DISCLOSURE: The following authors have nothing to disclose: George Juan, Saleem Shahzad, Mark Genovesi
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