Until recently, bronchioalveolar carcinoma (BAC) encompassed various premalignant lesions of pulmonary adenocarcinoma that develops from the epithelium of the terminal bronchioles and their acini at the peripheries of the lung and was distinguished by the absence of blood vessel or pleural involvement (also known as lepidic growth) [1] [2]. Because of its poor histological and radiographic specificity, bronchioalveolar carcinoma was recently replaced with the terms pulmonary adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), with mucinous, non-mucinous and mixed forms as subtypes of both lesions [2] [3] [4] [5] [6]. In addition, subtypes of invasive adenocarcinoma (lepidic predominant adenocarcinoma - LPA, and invasive mucinous adenocarcinoma) are also terms that have arisen from BAC [3]. One of the most important features of BAC is that its clinical presentation, comprised of a cough, chest pain and the production of sputum, can have a broad differential diagnosis (infections, hypersensitivity pneumonitis, etc.) [1]. The absence of fever, however, which is never seen in BAC, should point toward a noninfectious etiology [1]. Unfortunately, more than 60% of patients have no apparent symptoms, thus the diagnosis might be difficult to make [1]. But because BAC is a premalignant lesion and because 5-year survival rates are 100% if appropriate therapy is implemented early on, usually in the form of surgical resection, recognition of these lesions is vital in limiting its progression to a malignant tumor, which then carries a significantly poor prognosis regardless of the stage [6] [7].

Premalignant lesions of the lungs can only be detected with a comprehensive approach, starting with a detailed patient history and a complete physical examination that could possibly identify an ongoing pathological process in the lungs. As signs and symptoms are often lacking, however, imaging studies, a full laboratory workup, and pathohistological evaluation are necessary steps. The absence of leukocytosis in the presence of respiratory symptoms can often exclude pneumonia and other infectious processes [1]. Conversely, the use of imaging procedures provides essential clues in making a presumptive diagnosis [1]. Recent reports have established that BAC (or all of its newly described variants) appears as a solitary nodule ranging from 5-30 mm in diameter, although lobar, multilobar or even patchy infiltrates may be seen on plain radiography or computed tomography (CT), suggesting its multicentric development in some patients [1] [3] [5] [6]. CT is often preferred to chest X-rays, as it provides a better view of the lung parenchyma, but a biopsy of the lesion is often necessary, especially when inconclusive findings are seen on CT [5]. Thus, the diagnosis of BAC (now called AIS or MIA) now rests on radiographic criteria, but more importantly, on a proper histopathological examination [5] [6].

Treatment for bronchioloalveolar carcinoma depends on the stage and extent of the disease. Surgical resection, where the affected part of the lung is removed, is often the preferred treatment for localized BAC. In cases where surgery is not possible, other options include radiation therapy and chemotherapy. Targeted therapies, which focus on specific genetic mutations in cancer cells, may also be considered. The choice of treatment is tailored to the individual patient's condition and overall health.

The prognosis for bronchioloalveolar carcinoma varies based on several factors, including the stage at diagnosis and the patient's overall health. Early-stage BAC, particularly when it is classified as adenocarcinoma in situ, generally has a favorable prognosis with appropriate treatment. However, more advanced stages of the disease may have a poorer outlook. Regular follow-up and monitoring are essential to manage the disease effectively.

The exact cause of bronchioloalveolar carcinoma is not fully understood, but several risk factors have been identified. Smoking is a well-known risk factor for many types of lung cancer, including BAC. However, BAC can also occur in non-smokers. Other potential risk factors include exposure to environmental pollutants, a family history of lung cancer, and certain genetic mutations.

Bronchioloalveolar carcinoma is relatively rare compared to other types of lung cancer. It accounts for a small percentage of all lung cancer cases. BAC is more commonly diagnosed in women and non-smokers compared to other lung cancers. The incidence of BAC has been decreasing in recent years, likely due to changes in classification and diagnostic criteria.

Bronchioloalveolar carcinoma arises from the epithelial cells that line the alveoli and bronchioles. Unlike other lung cancers that form solid tumors, BAC spreads along the pre-existing structures of the lung, which can lead to a diffuse pattern of growth. This unique growth pattern can complicate diagnosis and treatment, as it may not form a distinct mass that is easily detectable.

Preventing bronchioloalveolar carcinoma involves reducing known risk factors. Smoking cessation is the most effective way to lower the risk of developing lung cancer. Avoiding exposure to environmental pollutants and carcinogens, such as asbestos and radon, can also help reduce risk. Regular health check-ups and screenings for those at high risk can aid in early detection and improve outcomes.

Bronchioloalveolar carcinoma is a rare subtype of lung cancer that presents unique challenges in diagnosis and treatment due to its growth pattern. While it shares some risk factors with other lung cancers, such as smoking, it can also occur in non-smokers. Early detection and tailored treatment are crucial for improving prognosis. Ongoing research continues to enhance our understanding of BAC and improve management strategies.

If you or someone you know is diagnosed with bronchioloalveolar carcinoma, it's important to understand the nature of the disease and the available treatment options. BAC is a type of lung cancer that can spread along the airways and air sacs in the lungs. Symptoms may include a persistent cough, shortness of breath, and chest pain. Treatment options vary based on the stage of the disease and may include surgery, radiation, chemotherapy, or targeted therapies. Regular follow-up with healthcare providers is essential to monitor the condition and adjust treatment as needed.

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