Rat tail sign



The rat tail sign refers to the infiltration of the bronchial lung cancer along the longitudinal axis of the bronchi, causing the bronchus to have a tail-like narrow and irregular defect.



Esophageal ectopic, lung cancer, cholangiocarcinoma, etc.


an examination

Related inspection

White blood cell movement inhibition test chest CT examination cardiopulmonary exercise test (CPET)

1. Irritating cough, mostly dry cough or white foam.

2. Blood stasis is often bloody or bloodshot in the sputum.

3. When the cancer grows up and the bronchus is blocked to varying degrees, symptoms and signs such as chest tightness, asthma, shortness of breath, localized wheezing, and local emphysema may occur.

4. When the bronchus is completely obstructed, signs of lung atelectasis in the corresponding lung tissue appear.

Diagnose based on:

1. Irritating cough, dry cough or white foam, bloody spots or bloodshot eyes.

2. Chest tightness, asthma, shortness of breath.

3. Localized snoring, localized emphysema or signs of atelectasis.

4. X-ray chest radiograph: see a uniform density in the lungs, uneven edges or lobes, or round or oval edges in the lungs with notch or burr shadows, sometimes local emphysema, atelectasis Wait.

5. Cytological examination to find cancer cells.

6. Bronchoscopy to see cancerous lesions.


Differential diagnosis

1. Tuberculosis: Especially tuberculoma (ball) is sometimes difficult to distinguish from peripheral lung cancer. Pulmonary tuberculoma (ball) is more common in young patients under the age of 40. The course of disease is longer, and there is less blood in the sputum. There is less change in erythrocyte sedimentation rate. Tuberculosis is found in 16% to 28% of patients. The chest radiograph is mostly round, found in the tip or posterior segment of the upper lobe, the volume is small, generally not more than 5cm in diameter, the boundary is smooth, and the density is uneven, calcification is visible. In 16% to 32% of cases, the drainage bronchus is visible to the hilar, less Pleural shrinkage occurs, and the growth is slow. For example, there is a hollow in the center liquefaction, and the middle is thin and the inner edge is smooth. There are often scattered tuberculosis lesions around the tuberculoma (ball) called satellite foci. Peripheral lung cancer is more common in patients over 40 years old, with more blood in the sputum, and 40% to 50% of cancer cells in the sputum. X-ray chest radiographs are often lobulated, with irregular edges, small burr and pleural shrinkage, and rapid growth. In some cases of chronic tuberculosis, lung cancer can occur on the basis of tuberculosis. Therefore, in adult patients with chronic tuberculosis, if abnormal lung shadows appear in the lungs, the hilar shadows increase or after regular anti-tuberculosis drugs are treated, the lesions do not increase and then increase. When you are old, you should suspect the possibility of lung cancer. Further sputum cytology and bronchoscopy should be performed and a thoracotomy should be performed if necessary.

2. Pulmonary inflammation: Bronchial pneumonia in elderly patients is sometimes difficult to distinguish from obstructive pneumonia caused by lung cancer obstructing the bronchi. Obstructive pneumonia often has a fan-shaped distribution according to the bronchial branches, while the general bronchopneumonia has irregular flaky shadows. However, if pneumonia has multiple episodes in the same site, it should be vigilant. It should be highly suspected of tumor blockage. The patient's sputum should be taken for cytological examination and fiber light-guided vascular examination. In some cases, pulmonary inflammation Absorption, when the remaining inflammation is wrapped by fibrous tissue to form nodules or inflammatory pseudotumors, it is difficult to distinguish from peripheral lung cancer. In suspicious cases, lobectomy should be performed to avoid delay in treatment.

3. Benign tumors of the lungs and bronchial adenomas: Benign tumors of the lungs, such as structural tumors, chondromas, and fibroids, are rare, but they must be differentiated from peripheral lung cancer. Generally, benign tumors have a longer course and slower growth. Most of the clinical symptoms are absent. X-ray films often have round shadows, neat edges, no burrs, and no lobes. Bronchial adenoma is a low-grade malignant tumor, often occurring in younger women, mostly originating from the larger bronchial mucosa. Therefore, there are often pulmonary infections and hemoptysis caused by bronchial obstruction in the clinic. Ventiloscopy can often make a diagnosis.

4. Mediastinal malignant lymphoma (lymphosarcoma and Hodgkin's disease): Clinically, there are often symptoms such as cough and fever. X-ray films show a widening of the mediastinum and are lobulated, sometimes difficult to distinguish from central lung cancer. If there is swelling of the lymph nodes on the supraclavicular or axillary fossa, it is often clear that the biopsy is used for pathological sectioning. Lymphosarcoma is particularly sensitive to radiation therapy. For suspicious cases, small doses of radiation therapy can be tried. When the temperature reaches 5-7 Gy, the mass can be significantly reduced. This experimental treatment also contributes to the diagnosis of lymphosarcoma.