Adenocarcinoma in situ of the lung

The bronchioloalveoläre carcinoma (BAC ) is a tumor of the lung. The bronchioloalveoläre carcinoma is expected within the lung to the adenocarcinomas. This carcinoma is different from the other lung cancer in that it often grows relatively slowly, no invasive growth shows and rarely metastasizes outside the lung. It has an overall better prognosis than other lung. Obsolete terms for the FOC are alveolar or malignant pulmonary adenomatosis. Occasionally, there are also different variations of the name, such as bronchoalveolar carcinoma or bronchio - alveolar carcinoma.

Pathology

When bronchioloalveolären carcinoma can be found usually well-differentiated tumor cells, the single-layered lining alveolar walls like wallpaper. The tumor grows and the non-invasive lung structure is maintained. In addition to these pure BAK there are adenocarcinomas, some of which grow invasively and partly bronchioloalveoläres growth patterns have (mixed adenocarcinoma with BAC component). Some studies suggest that the prognosis of these mixed adenocarcinomas is more unfavorable, the greater the invasive, solid proportion in relation to the BAC percentage. Furthermore, we distinguish a mucinous ( slime -forming ) BAC of a non- mucinous BAC. Generally the shape is associated with a mucinous somewhat poorer prognosis.

In the past few years have seen increased efforts to reclassify the whole of the lung tumors. It was suggested to the concept to renounce " Bronchioloalveoläres carcinoma " entirely and instead according to a new division names such as " adenocarcinoma in situ" (AIS ) or " minimally invasive adenocarcinoma " ( MIA) to use (as of June 2012).

Epidemiology

Approx. 5% of all lung cancer attributable to the bronchioloalveoläre carcinoma. It is striking that in comparison to the other forms of lung cancer suffer relatively many Non smoking and women in this tumor. Most patients are over 60 years old. The average age is about 66 years, about 6 % are younger than 50 years. The incidence in East Asia seems to be increased.

Diagnosis

In most cases, there is at initial diagnosis, a single ( solitary ) pulmonary nodule in the radiograph. Sometimes the X-ray image of a pneumonia similar (diffuse growth) or it can already be found at the beginning of multiple foci throughout the lung ( multilocular or multifocal ). As Miliarform is called a special form of multilocular BAK, in the spread innumerable small herd over both lungs. In computed tomography image is often recognizes a " milk glass -like lesion ". Histological examination is possible if, for example, obtained by a transthoracic biopsy tumor material. In many cases, the tumor is discovered incidentally in asymptomatic patients. In advanced cases may include cough, sputum ( mucinous form), weight loss ( cachexia ) and an increasing shortness of breath.

Therapy

As with the other non - small cell lung cancer you will go for surgical removal of the tumor in the early stages. It is questionable whether the case of very small tumors limited surgery ( segmentectomy or wedge ) of the lobe distance ( standard lobectomy ) may be preferred. For this run, several clinical studies (May 2008).

When discussing the benefits of lung cancer screening using CT emerged in recent years repeated the question as to whether some lung tumors found by chance may grow so slowly that a patient from therapy benefited little. It is controversial whether a part of the very small (5 mm diameter) bronchioloalveolären carcinomas could represent such " indolent lung cancers " ( indolent tumor).

In advanced stages, provides a chemotherapy, a (repeated ) resection (some with laser ) of several herd by wedge resections ( controversial ), radiation and as a last resort to a lung transplant.

At present, studies on the use of erlotinib and gefitinib are performed as Erstmedikation and in combination therapy. There are indications that these drugs ( tyrosine kinase inhibitors ) in the presence of a mutation in the region of the EGFR receptor, have a relatively high response (symptom improvement, recovery of the radiographic findings ). The probability of such a mutation appears to be greater for bronchioloalveoläre carcinomas and adenocarcinomas, compared to other mixed forms of lung cancer.

Forecast

Five years after diagnosis live approximately 40-50 % of patients. After surgical removal of the initial stage, the five-year survival rate is even partially over 80%. In advanced stages, when the tumor has spread to several lobes of the lungs and causes symptoms, the prognosis is bad, however.