Pulmonary Hamartoma

Axial Non-Contrast CT soft tissue window showing fat density areas within the pulmonary nodule

Axial Non-Contrast CT lung window showing central calcification within the pulmonary nodule

Axial Non-Contrast CT soft tissue window showing central calcification and fat density areas within the pulmonary nodule.

Teaching point:

Solitary pulmonary nodule with intrinsic calcium and macroscopic fat.

Etiology:

Benign pulmonary neoplasm containing varying amounts of a variety of tissues

• Cartilage
• Fat
• Connective tissue
• Smooth muscle
• Epithelial-lined clefts

CT

• Solitary nodule or mass, smooth or lobular borders
• Calcification more common in larger hamartomas
• Classic "popcorn" calcification in only 10-15%
• Fat attenuation in up to 60%
• Intrinsic fat and calcium virtually diagnostic

Sometimes FDG and Ga Dotatae avid. 

References:

1. Khan AN, Al-Jahdali HH, Allen CM, Irion KL, Al Ghanem S, Koteyar SS. The calcified lung nodule: What does it mean? Ann Thorac Med. 2010 Apr;5(2):67-79. doi: 10.4103/1817-1737.62469. PMID: 20582171; PMCID: PMC2883201.
2. Song H, Guja KE, Yang EJ, Guo HH. 64Cu-DOTATATE Uptake in a Pulmonary Hamartoma. Clin Nucl Med. 2023 Jan 1;48(1):58-60. doi: 10.1097/RLU.0000000000004390. Epub 2022 Sep 6. PMID: 36469060..
3. Cangir AK, Orhan K, Kahya Y, Uğurum Yücemen A, Aktürk İ, Ozakinci H, Gursoy Coruh A, Dizbay Sak S. A CT-Based Radiomic Signature for the Differentiation of Pulmonary Hamartomas from Carcinoid Tumors. Diagnostics (Basel). 2022 Feb 5;12(2):416. doi: 10.3390/diagnostics12020416. PMID: 35204507; PMCID: PMC8871366.