obsolete non-mucinous bronchioloalveolar lung carcinoma

Obsolete Non-Mucinous Bronchioloalveolar Lung Carcinoma

Non-mucinous bronchioloalveolar lung carcinoma, also referred to as non-mucinous bronchoalveolar carcinoma, is an obsolete term that was previously used to describe a subtype of lung cancer. This type of cancer was characterized by its unique features and demographics.

Key Characteristics:

• Morphology: Non-mucinous bronchioloalveolar lung carcinoma was a morphologic variant of minimally invasive lung adenocarcinoma, characterized by the presence of Clara cells and/or type II cells, tall columnar epithelial cells (1).
• Clinical Presentation: This subtype of lung cancer disproportionately affected women, never-smokers, and Asians (14).

Terminology:

The term "non-mucinous bronchioloalveolar carcinoma" was used to describe this subtype of lung cancer. However, it is now considered obsolete and has been replaced by more specific and accurate terminology.

References:

• The International Association for the Study of Lung Cancer (IASLC) recommends dropping the term "bronchioloalveolar carcinoma" altogether due to its lack of clear conceptual meaning (13).
• A study published in Clin Lung Cancer in 2008 suggests that non-mucinous and mucinous subtypes of adenocarcinoma with bronchioloalveolar carcinoma features differ by biomarker expression and response to therapy (30).

Citations:

1. [4] - Definition of non-mucinous bronchioloalveolar lung carcinoma.
2. [14] - Demographics affected by non-mucinous bronchioloalveolar lung carcinoma.
3. [13] - Recommendation to drop the term "bronchioloalveolar carcinoma".
4. [30] - Study on biomarker expression and response to therapy in non-mucinous and mucinous subtypes of adenocarcinoma with bronchioloalveolar carcinoma features.

Common Signs and Symptoms

Bronchioloalveolar carcinoma (BAC), also known as adenocarcinoma in situ, minimally invasive adenocarcinoma, or invasive adenocarcinoma of the lung, is a rare type of non-small cell lung cancer. While it's an obsolete term, understanding its symptoms can help with diagnosis and treatment.

• Cough: A persistent cough is one of the most common symptoms of BAC, often accompanied by blood (hemoptysis) [1][6][11].
• Breathing difficulties: Shortness of breath or dyspnea can occur as the cancer grows and affects lung function [4][14].
• Weight loss: Unintentional weight loss is another symptom associated with BAC, often due to decreased appetite and metabolism changes [6][14].
• Chest pain: Chest pain or discomfort can be a symptom of BAC, especially if the tumor has grown large enough to press on surrounding structures [1][11].

Other Possible Symptoms

While less common, other symptoms may include:

• Sputum production: Excessive sputum production (bronchorrhea) is an unusual but possible manifestation of BAC [12].
• Fever: Fever can occur in some cases, especially if the cancer has spread or caused a secondary infection [12].

Demographics

BAC tends to affect non-smokers, Asians (specifically eastern Asians), and women more frequently than other populations [15].

Diagnostic Tests for Non-Mucinous Bronchioloalveolar Lung Carcinoma

Non-mucinous bronchioloalveolar lung carcinoma (BAC) is a rare subtype of lung cancer that can be challenging to diagnose. However, several diagnostic tests can help identify this condition.

• Sputum Cytologic Studies: This test involves examining the mucus produced by the lungs for abnormal cells. While it may not be as effective for non-mucinous BAC, it can still provide valuable information in some cases [5].
• Bronchoscopy: A bronchoscope is inserted through the mouth or nose to visualize the airways and take tissue samples for examination. This test can help identify abnormalities in the lung tissue and confirm a diagnosis of non-mucinous BAC [9].
• CT-Guided Transthoracic Needle Biopsy: This minimally invasive procedure involves using a CT scan to guide a needle into the affected area, allowing for a tissue sample to be taken. This test can provide a definitive diagnosis of non-mucinous BAC [5].
• Pulmonary Biopsy: A pulmonary biopsy involves removing a small piece of lung tissue for examination under a microscope. This test is considered the gold standard for diagnosing non-mucinous BAC and can help confirm the presence of cancer cells in the lungs [3].

Other Diagnostic Considerations

In addition to these diagnostic tests, other factors should be taken into consideration when evaluating patients with suspected non-mucinous BAC.

• Imaging Studies: Chest X-rays and CT scans can provide valuable information about the size and location of any lung lesions. However, they may not always accurately distinguish between non-mucinous BAC and other types of lung cancer [6].
• Pathological Examination: A thorough pathological examination of the tissue sample is essential for confirming a diagnosis of non-mucinous BAC. This involves examining the tissue under a microscope to look for characteristic features such as lepidic growth patterns and lack of invasion into surrounding tissues [15].

References

[5] - A relatively uncommon type of non-small cell lung cancer, bronchioloalveolar carcinoma develops in the small air sacs (alveoli) in the outer layer of the lungs. Typically, the cancer originates in the lung periphery and grows along alveolar walls and airways, but does not affect the portion of the lung involved in gas transfer (parenchyma).

[9] - Early diagnosis of lung cancer plays a pivotal role in reducing lung cancer death rate. Cytological techniques are safer, economical and provide quick results.

[3] - Introduction. The description of disease consistent with bronchioloalveolar carcinoma (BAC) dates back to the 1800's. The reported incidence of BAC in the literature has ranged from 4% to 29% of non-small cell lung cancer (NSCLC) cases.

The differential diagnosis for non-mucinous bronchioloalveolar (BAC) lung carcinoma, now considered an obsolete term, involves several types of lung cancer and other conditions. Here are some key points to consider:

• Adenocarcinoma in situ: This is a preinvasive form of adenocarcinoma that shows lepidic growth with no stromal, vascular or pleural invasion [7]. It can be considered as a differential diagnosis for non-mucinous BAC.
• Minimally invasive adenocarcinoma: This type of lung cancer is characterized by small tumor size and minimal invasion into the surrounding tissue. It may be confused with non-mucinous BAC due to its similar histological features [2].
• Invasive adenocarcinoma: As a more advanced form of adenocarcinoma, invasive adenocarcinoma can also be considered in the differential diagnosis for non-mucinous BAC.
• Squamous cell lung carcinoma: This type of lung cancer is typically positive for p40 or p63 markers and can be distinguished from adenocarcinoma based on its different histological features [10].
• Other conditions: Other conditions such as atypical adenomatous hyperplasia, adenocarcinoma in situ, and other types of lung cancer may also need to be considered in the differential diagnosis for non-mucinous BAC.

It's worth noting that the classification system has changed, and non-mucinous bronchioloalveolar carcinoma is no longer a valid term. The new classification strategy introduced by the International Association for the Study of Lung Cancer (IASLC) and the American Society of Clinical Oncology (ASCO) in 2011 provides four new terms: adenocarcinoma in situ, minimally invasive adenocarcinoma, invasive adenocarcinoma, and lepidic-predominant lung adenocarcinoma [12].

References:

[2] - The term bronchoalveolar carcinoma has been replaced by the classification of lung adenocarcinoma into four subtypes: adenocarcinoma in situ, minimally invasive adenocarcinoma, invasive adenocarcinoma, and lepidic-predominant lung adenocarcinoma [2].

[7] - Adenocarcinoma in situ is a preinvasive form of adenocarcinoma that shows lepidic growth with no stromal, vascular or pleural invasion [7].

[10] - Squamous cell lung carcinoma is typically positive for p40 or p63 markers and can be distinguished from adenocarcinoma based on its different histological features [10].

[12] - The classification system has changed, and non-mucinous bronchioloalveolar carcinoma is no longer a valid term. The new classification strategy introduced by the IASLC and ASCO in 2011 provides four new terms: adenocarcinoma in situ, minimally invasive adenocarcinoma, invasive adenocarcinoma, and lepidic-predominant lung adenocarcinoma [12].