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A4047 - Diffuse Bronchoalveolar Carcinoma: A Rare Type of Pulmonary Adenocarcinoma
Author Block: K. Lasafin; Department of Medicine- Section of Pulmonary Medicine, Makati Medical Center, Makati City, Philippines.
Introduction: Bronchoalveolar carcinoma (BAC) now being termed as “adenocarcinoma in situ”, is a rare pulmonary neoplasm accounting for 2% to 14% of all pulmonary malignancies. Patients may be asymptomatic or present with cough and shortness of breath but its rate of progression can be extremely variable. This should be included in differentials of an interstitial type of lung disease, particularly if it is not responding to antibiotics and corticosteroid therapy. Case Description: We present a case of a 81 year old Filipina, non smoker, presenting with 1 week history of dyspnea with non productive cough and poor appetite, was admitted as case of pneumonia in the elderly. Chest CT scan, showed ground glass opacities with interlobular septal thickening in both lungs, more extensive in apical segment of both upper lungs and also in bilateral lower lobes. Mild bronchiectatic changes with subcentimeter air cysts, prominent mediastinal lymph nodes and minimal bilateral pleural thickening. Further infectious work-up revealed sputum cultures showed Candida albicans; sputum MTB gene xpert, sputum PCP-PCR, serum Cryptococcal antigen, CMV PCR, serum Mycoplasma IgM and blood cultures all turned out negative. Despite several course of antimicrobials, bronchodilators and IV corticosteroid therapy, patient’s clinical condition worsened. Repeat Chest CT scan showed interval increase in ground glass opacities with consolidation in bilateral lower lobes. Lung biopsy of the consolidated lung at the right lower lobe revealed adenocarcinoma. Discussion: Bronchoalveolar carcinoma (BAC) is a subtype of adenocarcinoma that appears to arise from type II pneumocytes. It may manifest radiologically as a solitary peripheral nodule (40%), diffuse ill-defined centrilobular nodules (30%), or rapidly progressing pneumonic form. BAC can be slow growing while some tumors can progress rapidly and lead to decline lung capacity. Treatment of choice is complete surgical resection for focal disease; however diffuse forms are often responsive to targeted chemotherapies. Long-term survival rates in BAC tend to be higher than other forms of non small cell lung cancer. Mortality is worse if the tumor has diffuse lesions. Bronchoalveolar carcinomas can mimic an inflammatory interstitial lung disease or present as a non resolving pneumonic form, hence this highlights the importance of including this in one of the differential diagnosis and reinforces the importance of tissue diagnosis in patients with an interstitial lung disease.