Large-cell lung carcinoma (LCLC) is a heterogeneous group of undifferentiated malignant neoplasms originating from transformed epithelial cells in the lung.

Incidence

In most series, LCLC's comprise between 5% and 10% of all lung cancer

Lung cancer

Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...

s.

According to the Nurses' Health Study

Nurses' Health Study

The Nurses Health Study, established in 1976 by Dr. Frank Speizer, and the Nurses' Health Study II, established in 1989 by Dr. Walter Willett, are the most definitive long-term epidemiological studies conducted to date on older women's health. The study has followed 121,700 female registered...

, the risk of large cell lung carcinoma increases with a previous history of tobacco smoking

Tobacco smoking

Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...

, with a previous smoking duration of 30 to 40 years giving a relative risk

Relative risk

In statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....

 of approximately 2.3 compared to never-smokers, and a duration of more than 40 years giving a relative risk of approximately 3.6.

Diagnosis

LCLC is, in effect, a "diagnosis of exclusion", in that the tumor cells lack light microscopic characteristics that would classify the neoplasm as a small-cell carcinoma, squamous-cell carcinoma, adenocarcinoma, or other more specific histologic type of lung cancer.

LCLC is differentiated from small-cell lung carcinoma (SCLC) primarily by the larger size of the anaplastic cells, a higher cytoplasmic-to-nuclear size ratio, and a lack of "salt-and-pepper" chromatin.

Classification

The newest revisions of the World Health Organization Histological Typing of Lung Cancer schema include several variants of LCLC, including (a) basaloid, (b) clear cell, (c) lymphoepithelioma-like, (d) rhabdoid phenotype, and (e) large-cell neuroendocrine carcinoma.

In addition, a "subvariant", called "combined large-cell neuroendocrine carcinoma", or c-LCNEC, is recognized under the new system. To be designated a c-LCNEC, the tumor must contain at least 10% LCNEC cells, in combination with at least 10% of other forms of NSCLC.

Large-Cell Neuroendocrine Carcinoma (LCNEC)

One clinically significant subtype is "large-cell neuroendocrine carcinoma", which is believed to derive from neuroendocrine cells.

External links

• http://www.lmp.ualberta.ca/resources/pathoimages/PC-K,L.htm