INTRODUCTION: Bronchioloalveolar cell carcinoma (BAC) presents in a variety of different radiological patterns. We report an unusual radiological presentation of BAC with multifocal bilateral cavitating lesions.
CASE PRESENTATION: A 55 year old Caucasian male with 15 pack-year history of smoking and otherwise no significant past medical history, was admitted for treatment of pneumonia. He was symptomatic for productive cough, shortness of breath and chest radiograph showed a right lower lobe infiltrate. A chest computed tomography (CT) showed mixed areas of gas and fluid throughout an opacified right lower lobe, and a loculated right pleural effusion. Bronchoscopy with lavage was negative for bacterial, fungal, and mycobacterial organisms. Due to lack of clinical or radiological improvement, the patient underwent right lower lobectomy with decortication and was found to have organizing pneumonia with fibrosis, and foci of mucinous type BAC. Surveillance chest CT scans over the next 2 years revealed progressive bilateral cavitating nodules. Repeat bronchoscopy was negative. Positron emission tomography (PET)-CT scan did not show significant uptake in the lesions. The patient underwent a thoracoscopic wedge resection of the left upper lobe cavitatory lesion. There were multiple microscopic nodules of BAC. Epidermal growth factor receptor (EGFR) status was negative and patient was evaluated for initiation of cytotoxic chemotherapy.
DISCUSSIONS: Bronchioloalveolar cell carcinomas account for about 4% of all non small cell lung cancers. They exhibit a lepidic growth pattern (growth along intact alveolar septae), aerogenous and lymphatic spread, but without vascular invasion. BAC differs from other lung cancers as there is a female preponderance (53%), and a significant number of lifelong nonsmokers(37%) are affected. Clinical symptoms include cough, shortness of breath, and hemoptysis. Bronchorrhea (>100ml/24hrs) and intrapulmonary shunting due to replacement of alveoli with tumor can be life threatening. Often, patients are asymptomatic with incidentally detected radiological abnormalities (1)Radiologically, three patterns are reported: (a) solitary pulmonary nodules or mass, (b) consolidative changes resembling pneumonia, or (c) multifocal nodules or masses. The solitary nodule is the most frequent radiographic presentation(56%) and can be a ground glass opacity or more solid with ill defined margins. Intratumoral radiolucencies in the form of air bronchograms, pseudocavitation, heterogenous attenuation and pleural tags are often present. Diffuse consolidative changes are present in 30% of the patients making it difficult to differentiate from bacterial pneumonia. Multifocal disease is seen in the form of groundglass opacities, solid nodules or masses and occurs frequently with the mucinous subtype. Cavitatory forms of BAC are exceedingly rare. The CT angiogram sign described in BAC as visible vessels with contrast through an area of tumor, can be seen in benign consolidative conditions.(2) Surgical resection is the therapy of choice in early stage tumor. In patients with EGFR mutations and advanced disease, chemotherapy with EGFR inhibitors has shown improved outcomes. Radiation therapy and outcomes are similar to other non small cell lung cancers.The prognosis of patients with surgically resected solitary nodules is good with five year survivals in the 100% range with low rates of recurrence. The multifocal and consolidative forms have a poorer prognosis.
CONCLUSION: In the absence of infectious or inflammatory etiologies, BAC and other lung cancers should be considered in the differential diagnosis of cavitatory lung disease.
DISCLOSURE: Charbel Maskiny, No Financial Disclosure Information; No Product/Research Disclosure Information