The procedure was uneventful, and the patient was discharged home on the same day. Histology showed the mass to be expanded by connective tissue with mature fat and cartilage dominance, with features consistent of a bronchial chondromatous hamartoma. There were no features of malignancy (Fig. 3A, B). The patient had an uneventful recovery with complete resolution of symptoms when seen in the follow-up visit at 2 weeks.
The incidence of pulmonary hamartoma in the general population is 0.25%.1 According to Minasian,2 of 3450 patients subjected to thoracotomy for pulmonary neoplasms, 33 patients had hamartoma. Only 2 of the hamartomas were endobronchial.
Hamartomas present a peak incidence in the sixth decade of life and are 2 to 4 times more common in men than in women. They typically present as single, well-circumscribed, round nodules.3
A pulmonary hamartoma is usually consisted of a mixture of cartilage, fat, fibrous tissue, and smooth muscle, and of branching clefts of non-neoplastic reactive bronchial-type epithelium. Actually, the word “hamartoma” deriving from Greek terms meaning “error” and “tumor,”4 was first used by Albrecht5 in 1904 to describe lesions that contained an abnormal mixture of normal components of an organ. Pulmonary hamartoma was thought to arise from embryologic rests that were present in fetal life, but generally did not become visible until adulthood. Yet, cytogenetic analysis of these lesions showed an abnormal karyotype and revealed recombination between chromosomal bands 6p21 and 14q24, thus supporting the opinion that a hamartoma of the lung was a true neoplasm.6
The histology of the parenchymal lesions usually reveals a predominant chondromatous differentiation (80%), with fibroblastic (12%), fatty (5%), and osseous (3%) differentiation making the rest.7
Pulmonary hamartomas are usually asymptomatic and are found incidentally on chest x-rays obtained for other reasons.8 In contrast, endobronchial hamartoma is often symptomatic, and the most common complaints of patients are hemoptysis and obstructive pneumonia. Sometimes the patients present with dyspnea, cough, and wheezing. Therefore, the diagnosis of asthma is often mistakenly given to patients.9 This was typical in our patient. Chest x-ray and lung CT scan in endobronchial hamartomas show endobronchial space-occupying lesions, collapse, obstructive pneumonia, and air entrapment within the lungs.8
The most definitive method of diagnosis is bronchoscopy and biopsy of the lesion10 preferably through a rigid bronchoscopy as small biopsies might not reveal the diagnosis as the hamartoma can be covered by normal epithelium. Rigid bronchoscopy can also be therapeutic, which was evident in our case. The management of endobronchial hamartoma must be individualized according to the characteristics of each patient and the location of the tumor.
Bronchoscopy and chest CT scans are valuable investigations and should be performed in any older patients with a prolonged picture of late-onset asthma. Adequate tissue sample for diagnosis of benign tumors is difficult to obtain through flexible bronchoscopy, as they are usually covered with normal epithelium. A rigid bronchoscopy and biopsy/removal of the mass are the treatments of choice.
1. McDonald JR, Harrington SW, Clagett OT. Hamartoma (often called chondroma) of the lung J Thorac Surg.. 1945;14:128–143
2. Minasian H. Uncommon pulmonary hamartomas Thorax.. 1977;32:360–364
3. Kiryu T, Kawaguchi S, Matsui E, et al. Multiple chondromatous hamartomas of the lung: a case report and review of the literature with special reference to Carney Syndrome Cancer.. 1999;85:2557–2561
4. Murray J, Kielkowski D, Leiman G. The prevalence and age distribution of peripheral pulmonary hamartomas in adult males: an autopsy-based study S Afr Med J.. 1991;79:247–249
5. Albrecht D. Ueber Hamartome Verh Dtsch Ges Pathol.. 1904;7:153–157
6. Johansson M, Dietrich C, Mandahl N, et al. Recombinations of chromosomal bands 6p21 and 14q24 characterize pulmonary hamartomas Br J Cancer.. 1993;67:1236–1241
7. Colby TV, Koss MN, Travis WD. Tumours of the Lower Respiratory Tract Atlas of Tumor Pathology. 1994 Washington, DC Armed Forces Institute of Pathology:319–325 . 3rd Series, Fascicle 13.
8. Yilmaz S, Ekici A, Erdogan S, et al. Endobronchial lipomatous hamartoma: CT and MR imaging features (2004:5b) Eur Radiol.. 2004;14:1521–1524
9. Bernabeu Mora R, Garcia Martin E, Polo Garcia LA, et al. Endobronchial chondroid hamartoma
presenting as asthmatic attack An Med Interna.. 2003;20:271–272
10. Cosio BG, Villena V, Echave-Sustaeta J, et al. Endobronchial hamartoma Chest.. 2002;122:202–205
Keywords:© 2011 Lippincott Williams & Wilkins, Inc.
endobronchial lesions; chondroid hamartoma; therapeutic bronchoscopy