Bronchoalveolar carcinoma
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor-in-Chief: Khuram Nouman, M.D. [2]
Overview
Historical Perspective
- Bronchoalveolar Carcinoma was first described by Malassez in 1876 as a bilateral, multinodular type of malignant lung carcinoma.
- The term "Bronchoalveolar cell carcinoma" was first introduced by Liebow in 1960 due to confusion over true cell type.It comes from two cell types. columnar epithelium similar to bronchial cells and cuboidal type reminiscent of type 2 pneumocytes.
- In [year], [gene] mutations were first identified in the pathogenesis of [disease name].
- In [year], the first [discovery] was developed by [scientist] to treat/diagnose [disease name].
Classification
- Bronchoalveolar Carcinoma may be classified according to pathology into fo subtypes/groups:
- Pathology of lung adenocarcinomas according to previous 2004 WHO and current IASLC/ATS/ERS classifications[1]
| 2004 WHO classification |
| Mixed subtype |
| Acinar |
| Papillary |
| BAC |
| Non mucinous |
| Mucinous |
| Mixed |
| Solid adenocarcinoma |
| Colloid |
| Fetal |
| Mucinous cystadenocarcinoma |
| Signet-ring |
| Clear-cell |
| Major changes in the new IASLC/ATS/ERS classification |
| Discontinuation of the term BAC |
| Discontinuation of the mixed subtype |
| Comprehensive pathologic subtyping in 5% increments and classification of adenocarcinomas according to the predominant subtype |
| Introduction of AIS and MIA as new entities |
| Introduction of micropapillary adenocarcinoma as a predominant subtype |
| Introduction of lepidic predominant adenocarcinoma and lepidic growth as new terminologies |
| Exclusion of signet-ring and clear cell adenocarcinomas |
| IASLC/ATS/ERS classification |
| Pre-invasive lesions |
| Atypical adenomatous hyperplasia |
| AIS |
| Non-mucinous |
| Mucinous |
| Mixed |
| MIA |
| Non-mucinous |
| Mucinous |
| Mixed |
| Invasive adenocarcinomas |
| Lepidic predominant |
| Acinar predominant |
| Papillary predominant |
| Micropapillary predominant |
| Solid predominant with mucin production |
| Variants of invasive adenocarcinomas |
| IMA |
| Colloid |
| Fetal |
| Enteric |
WHO, World Health Organization; IASLC, International Association for the Study of Lung Cancer; ATS, American Thoracic Society; ERS, European Respiratory Society; BAC, bronchioloalveolar carcinoma; AIS, adenocarcinoma in situ; MIA, minimally invasive adenocarcinoma; IMA, invasive mucinous adenocarcinoma.
Pathophysiology
- The pathogenesis of [disease name] is characterized by [feature1], [feature2], and [feature3].
- The [gene name] gene/Mutation in [gene name] has been associated with the development of [disease name], involving the [molecular pathway] pathway.
- On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
- On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
Clinical Features
Differentiating Bronchoalveolar carcinoma from other Diseases
- BAC must be differentiated from other diseases that cause cough, hemoptysis, and solitary nodule on X-Ray such as:
- Malignant and benign lesion
- Inflammatory
- Congenital
- miscellaneous
Epidemiology and Demographics
- Bronchoalveolar carcinoma is a rare tumor, the incidence of BAC vary from 4-24% of all the primary lung malignancies. More newer studies suggest Adenocarcinoma in situ and minimally invasive carcinoma constitutes 2-14% of all the primary types of lung cancers.
Age
- Patients of all age groups may develop [disease name].
- [Disease name] is more commonly observed among patients aged [age range] years old.
- [Disease name] is more commonly observed among [elderly patients/young patients/children].
Gender
- Bronchoalveolar Carcinoma affects men and women disproportionately.
- Women are more commonly affected with bronchoalveolar carcinoma than men.
Race
- Bronchoalveolar Carcinoma usually affects individuals of the Asian race.
Risk Factors
- Common risk factors in the development of BAC are Asian race, women gender, and pulmonary fibrosis.
Natural History, Complications and Prognosis
- The majority of patients with [disease name] remain asymptomatic for [duration/years].
- Early clinical features include [manifestation 1], [manifestation 2], and [manifestation 3].
- If left untreated, [#%] of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
- Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
- Prognosis is generally [excellent/good/poor], and the [1/5/10year mortality/survival rate] of patients with [disease name] is approximately [#%].
Diagnosis
Diagnostic Criteria
- The diagnostic criteria for bronchoalveolar carcinoma have changed over time.According to new 2011 IASLC/ATS recommendations, adopted in the 2015 WHO guidelines, use the following criteria for bronchoalveolar carcinoma
- Localized small tumor < 3 cm
- pure "lepidic growth"
- No stromal, vascular or pleural invasion
- Nuclear atypia absent/minimal in both mucinous/non-mucinous AIS
- Septal broadening with sclerosis (non-mucinous type)
- No spread through air spaces
Symptoms
- Bronchoalveolar carcinoma is usually asymptomatic.
- Symptoms of BAC may include the following:
- Cough
- Sputum
- Hemoptysis
- Chest pain
- Weakness
- loss of appetite
- Repeated Lung infections like pneumonia and bronchitis
Physical Examination
- Patients with BAC usually appear [general appearance].
- Physical examination may be remarkable for:
- [finding 1]
- [finding 2]
- [finding 3]
- [finding 4]
- [finding 5]
- [finding 6]
Laboratory Findings
- There are no specific laboratory findings associated with [disease name].
- A [positive/negative] [test name] is diagnostic of [disease name].
- An [elevated/reduced] concentration of [serum/blood/urinary/CSF/other] [lab test] is diagnostic of [disease name].
- Other laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
Imaging Findings
- There are three radiologic findings associated with bronchoalveolar carcinoma are,
- Solitary nodule- most common
- Consolidation
- multinodular opacities
- The nodular form is the commonest and can not be differentiated from other adenocarcinoma subtypes on plain X-ray.
- CT scan is imaging modality of the choice for bronchoalveolar carcinoma.
- Non-Mucinous BAC: It appears as solid nodule surrounded by ground glass opacification- Fried egg sign
- Mucinous BAC: It appears as single solid nodule.
-
CXR- Bronchoalveolar Carcinoma
-
CT SCAN: Bronchoalveolar Carcinoma
-
CT SCAN: Bronchoalveolar Carcinoma
Other Diagnostic Studies
- BAC may also be differentiated from invasive adenocarcinoma by using magnetic resonance imaging.
- Image guided per-cutaneous fine needle aspiration biopsy or core biopsy can be used to get molecular characteristic of the tumor.
Treatment
Medical Therapy
- Non-Mucinous BAC responds well to targeted chemotherapy like epidermal growth factor receptor tyrosine kinase inhibitors erlotinib and gefitinib.
- Patient with non-resectable tumor can benefit from erlotinib and gefitinib than other subtypes of non small cell lung carcinoma.
- Mucinous BAC are highly associated with K-RAS mutation and wild-type EGFR and does not respond well to EGFR tyrosine kinase inhibitor.
Surgery
- Surgery is the mainstay of therapy for bronchoalveolar carcinoma.
- Pneumonectomy or lobectomy in conjunction with ipsilateral lymphadenectomy is the most common approach to the treatment of BAC.
Prevention
- There are no primary preventive measures available for [disease name].
- Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
- Once diagnosed and successfully treated, patients with [disease name] are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].
References
- ↑ . doi:10.3978/j.issn.2072-1439.2014.01.27. Missing or empty
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