A 45-year-old asymptomatic nonsmoker is found to have a 1.5 cm well-circumscribed, solitary pulmonary nodule on routine chest X-ray. CT shows a 'popcorn' pattern of calcification. Resection reveals a well-encapsulated tumor composed of lobules of hyaline cartilage admixed with myxoid stroma, fat, and ciliated epithelium. What is the diagnosis?

• A Pulmonary hamartoma ✓
• B Carcinoid tumor
• C Pulmonary chondrosarcoma
• D Mesenchymal cystic hamartoma

Explanation

Pulmonary hamartoma is the most common benign lung tumor, presenting as a solitary 'coin lesion' with characteristic popcorn calcification on imaging. Histology shows disorganized mature tissues native to the lung: cartilage, fat, smooth muscle, and ciliated epithelium. It is benign with no malignant potential. Carcinoid (option B) shows organoid nesting of neuroendocrine cells, not cartilage.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.