Endobronchial hamartoma mimicking low-grade chondrosarcoma on biopsy: A diagnostic pitfall

Endobronchial cartilaginous tumors are rare and may pose a significant diagnostic challenge, particularly on limited biopsy material. The distinction between pulmonary hamartoma, chondroma, and low-grade chondrosarcoma relies largely on architectural features that are often not assessable in small samples. We report a case of an endobronchial lesion in which bronchoscopic biopsy fragments composed exclusively of mature hyaline cartilage raised the differential diagnosis of chondroma versus low-grade chondrosarcoma. Subsequent surgical resection revealed a well-circumscribed lesion composed of mature cartilage admixed with adipose tissue and entrapped bronchial epithelium, consistent with endobronchial hamartoma. This case highlights a classic diagnostic pitfall and underscores the limitations of biopsy in cartilaginous pulmonary tumors. Awareness of this entity is essential to avoid overdiagnosis and inappropriate aggressive management.