I. Overview: Pulmonary Sclerosing Hemangioma (PSH) ① is a rare benign tumor in the lung ② was first reported by foreign scholar Liebow in 1956, and is considered to be a primary lesion of vascular hyperplasia accompanied by secondary epithelial hyperplasia. In China, PSH is considered to be a flow-like proliferative lesion caused by non-specific inflammation and belongs to a special subtype of pulmonary inflammatory pseudotumor. ③Middle-aged women are more common ④Many scholars currently believe that PSH is a true tumor originating from the respiratory tract The tissue structure under light microscopy mainly includes: papillary area, sclerotic area, solid area, and hemorrhagic area The formation process: angiomatous area-à papillary area-à solid area-à sclerotic area II. Clinical features Most physical examinations are found incidentally, and some patients present with: cough, low-grade fever, chest pain, and blood in sputum III. Chest radiographic manifestations The masses are all solitary, round or oval, with uniform density, clear borders, smooth margins, no lobes or burrs, no mediastinal widening CT scan ① site and size: the right lower lobe of the lung is mostly lateral, the size is mostly 1-8 cm ② morphology and density: mostly garden-shaped or ductal round solitary masses, smooth margins, no burrs, occasionally shallow lobes, may be accompanied by calcification ③ mediastinal lymph nodes: occasionally enlarged, pathology ④Special features a: caudal sign b: adjoining vascular sign c: pulmonary artery dominant sign d: air crescent sign Enhancement features: small lesions show significant enhancement and long duration, large lesions show inhomogeneous enhancement in early stage due to different pathological components, delayed scan, slow persistent enhancement IV. cases V. differential diagnosis 1. tuberculosis spheres ① history of tuberculosis ② prevalent sites (upper and lower lobe dorsal segments of both lungs) ③ (3) Uneven density, caseous necrosis in the center, surrounded by fibrous streaks and satellite foci ④ No enhancement or circumferential enhancement ⑤ Mostly accompanied by punctate or laminar calcification 2, malformation tumor ①Male prevalence ②Uneven density, often containing fatty components, and calcification, typically popcorn-like calcification ③No enhancement or mild enhancement 3, peripheral type lung cancer ①Older age, male prevalence ②Clinical symptoms; chest pain, dry cough, blood in sputum ③Morphology ③ Irregular morphology: lobulation, short thin burrs and spiny protrusions, pleural depression sign, vacuolation sign ④ Enhancement: obvious enhancement, but lower than PSH, and short duration 4.Metastases: history of primary tumor, and often multiple 5.Inflammatory pseudotumor: history of chronic inflammation, and obvious improvement after anti-inflammatory treatment 6.Carcinoid tumor: obvious clinical symptoms: intermittent facial flushing, etc. “PSH is a rare benign intrapulmonary tumor, which usually occurs in middle-aged Asian women, with occasional occurrence, and the imaging manifestations are mostly isolated nodules or masses in the lung, with uniform density, clear borders, obvious and continuous enhancement, and close relationship with surrounding blood vessels. CT dynamic enhancement and 3D reconstruction are more helpful to show the specific signs of PSH, improve the diagnosis and differential diagnosis of PSH, the clinical use of surgical resection, the specific characterization still relies on pathology.