AB 49. Unusual intrabronchial location, large in size, of hamartoma in a patient with a mass in the left lung

Background: Pulmonary hamartoma is a benign tumor composed of cells and tissues, amorphous demarcated. It occurs in 0.25% of the general population (in autopsy material) and in 6-8% of all benign solitary lung nodules.

Patients and methods: A male patient, smoker 30 p/y, reports a month weakness, fatigue, low grade fever without weight loss. The XR of the chest showed a solid formation mass with fuzzy borders in contact with the left lung hilum. The chest CT revealed a lesion 5.5 cm × 4.5 cm in the anterior segment of the left upper lobe and little enlargment of lymph nodes (superior mediastinal, of aortopulmonary window and right paratracheal). Therefore, the patient underwent diagnostic bronchoscopy.

Results: The endoscopic image showed an exophytic lesion occludes one of the subsegment bronchi of the anterior of the left upper lobe with smooth, polished, pale yellow surface coalesced into a broad basis to the underlying bronchi. The difficulty in obtaining the biopsy material by the forcep (due to hardness) confirmed the histopathological examination which revealed particles of tissue, composed of adipose tissue, cartilage elements, sparse bone trabeculae, hematopoietic marrow elements and fibrin myxomatoid substrate, a typicall pulmonary hamartoma. The patient underwent thoracic MRI in order to exclude a possible coexisting lung cancer and for the evaluation of mediastinal lymph nodes, head, abdominal and bone CT scan (without pathological findings). It is expected the scheduling of surgical removal of the lesion as a definitive treatment for the patient.

Conclusions: Pulmonary hamartoma occurs most often in 5th-6th decade of life with a ratio males: females 3:1. Only in 10% is intrabronchial (mainly in the periphery of lung parenchyma) causing obstruction and rarely can have multiple localization (Cowden syndrome). It is usually an incidental finding on chest XR and appears with cough, fever, pain, or rarely hemoptysis. The diameter varies from a few mm up to 4 cm (average 2.5 cm, remarkable is the size of the lesion in our case). It doesn’t formate a pulmonary cavity while in 15% occurs central amorphous, almost pathognomonic, pop corn type calcifications. It grows slowly, about 5 mm per year. In a typical XR appears as a mass with clear boundaries and smooth edge and the characteristic (if it exists) calcifications, while CT scan detects the fat, the boundaries of the mass and the type of calcifications.