Pulmonary trichomycosis is a serious lung infection caused by certain pathogenic fungi in the subphylum Trichoderma of the fungal kingdom, also known as pulmonary splinter disease, which is a fungal infection of the lung with rapid onset, rapid progression and high mortality rate, and is relatively rare clinically and extremely difficult to diagnose and treat. Trichomycosis is divided into five types: pulmonary, nasal and cerebral, gastrointestinal, cutaneous, mixed and disseminated, of which pulmonary trichomycosis is the most common. 1, the etiology and epidemiology of a variety of fungi in the subphylum can cause the disease, the disease is caused by each “genus” in the “species”, these species have a wide range of names, clinical distinction is not easy, collectively referred to as jointed fungi or Trichophyton. Trichoderma is ubiquitous in nature, mainly in the soil and rotten food, growing rapidly, easy to form a large number of spores, into the respiratory tract. The virulence of Trichoderma is very weak, the body has a strong immunity to it, so the incidence of Trichoderma is very low. High sugar and acidic environment is conducive to the growth and reproduction of Trichoderma, so diabetic acidosis patients inhaling Trichoderma spores can easily progress to pulmonary trichinosis. In addition, with the increase of diseases such as AIDS, malignant tumors, the application of hormones and various immunosuppressive drugs and organ transplantation, the incidence of the disease has increased significantly. 2, pathology Infiltration, thrombosis and necrosis are characteristic changes of trichinosis. Trichoderma is very aggressive and has a special affinity for arterial vessels. Once fungal spores grow at the site of infection, their hyphae rapidly spread to surrounding tissues and readily invade blood vessels, forming thrombi that lead to ischemia, hypoxia, acidosis, and infarction of distal tissues, favoring further fungal spread and creating a vicious cycle. Microscopically, the lesion shows an acute inflammatory process with severe tissue necrosis and suppuration, and a large number of hyphae are visible in the lesion area, and rarely granulomas are seen, which is the characteristic change of the disease. Sometimes there is no inflammatory change around the mycelium. Trichophyton mycelium thick and thin uneven, 7-25μm in diameter, branching at right angles, wide without separation or rarely separated, thin wall, some places mycelium collapse, mycelium cross-section rather like spores. 3, clinical and imaging manifestations of pulmonary trichomoniasis symptoms are not specific, generally acute or subacute onset, the disease is usually more serious. Clinical manifestations include fever, cough, hemoptysis, chest pain and dyspnea. Clinical and laboratory tests are nonspecific, and most patients have elevated peripheral blood WBC counts. The most common imaging manifestations are progressive, homogeneous solid lesions in lobes or segments of the lung, or single or multiple pulmonary nodules or masses, with lesions in the upper lobes being more common, followed by the lower lobes; cavitation occurs in more than 40% of cases, and the air hemimelia sign is less common than in Aspergillus pneumonia, once present suggesting the possibility of hemoptysis, but the prognosis is relatively good; Trichophyton has a strong tissue penetrating ability, often eroding the pulmonary Small arteries, forming pulmonary artery embolism, pulmonary infarction, pulmonary aneurysm and pseudoangioma, the lesion progresses rapidly, if not treated, most die from hemoptysis. Pulmonary trichomoniasis can also appear pulmonary atelectasis, pleural effusion and mediastinal lymph node enlargement. 4 , diagnosis Trichophyton infection can only be clearly diagnosed by fungal pathogenesis and histopathology. In recent years, fungal antigen detection such as G test and GM test are negative in Trichophyton infection; the positive rate of sputum, needle aspirate and bronchoalveolar lavage fluid culture is less than 5%, and the positive rate of blood culture is even lower; confirming the diagnosis mainly relies on histopathology. Previously, because of the rapid progression of pulmonary trichinosis and high mortality rate, confirming the diagnosis mainly relies on autopsy. Currently, the most important method for diagnosing pulmonary trichinosis is fiberoptic bronchoscopic biopsy, and in more than 40% of cases, especially in diabetic patients, endotracheal lesions are seen: such as airway narrowing and obstruction, mucosal erythema and ulceration or mucus, purulent or gel-like secretions. Mycelial characteristics are described in section 2.5 Treatment 5. Once the diagnosis of pulmonary trichomycosis is confirmed, intravenous amphotericin B 1 to 1.3 mg/kg is started immediately for a course of at least 8 to 10 weeks at a total of 2 to 3 g, which can be combined with 5-fluorocytosine; if not tolerated, amphotericin B liposomes 3 to 5 mg/kg can be applied, and most other antifungal drugs are ineffective [5]. If intrathoracic infection is clearly present, amphotericin B intrathoracic injection can be applied. The new oral azole antifungal drug posaconazole has also been reported to be effective against Trichoderma. Other treatments include hyperbaric oxygen, cytokines, and iron chelators, the efficacy of which is unclear. Since Trichoderma is very easy to obstruct local blood vessels and bronchial tubes, it is difficult to achieve a high concentration of drugs in the focal area, and the effect of purely internal treatment is not satisfactory. Those whose symptoms do not improve after 2 weeks of amphotericin B application should undergo early surgical intervention to remove the lesion. It is also believed that pulmonary trichomycosis is a surgical emergency and should be treated surgically as soon as it is diagnosed. 6, prognosis The prognosis of the disease is closely related to the underlying disease, malignant hematologic disease, granulocyte deficient patients with pulmonary trichomycosis progresses rapidly, the prognosis is poor, most die within 7 d, even after active treatment measures, the death rate is still up to 75%; while patients with diabetes combined with pulmonary trichomycosis is relatively mild symptoms, the prognosis is good, the death rate is less than 12%, the reason may be because diabetes as the underlying disease than malignant Hematologic diseases are easier to control. Prognosis and treatment are closely related: without treatment, the mortality rate is almost 100%; with drug treatment alone, the mortality rate is as high as 50%; and with drug combined with surgical treatment, the mortality rate can be reduced to 11%.