대한흉부영상의학회 Weekly Chest Cases

Case No : 308 Date 2003-09-20

Courtesy of Jung Im Jung, M.D. / St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
Age/Sex 63 / M
Chief ComplaintIncidentally found pulmonary mass

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Diagnosis With Brief Discussion

Diagnosis: Pulmonary Hamartoma
Radiologic Findings: PA and lateral chest shows well-defined 6x5cm sized mass in superior segment of right lower lobe. Precontrast CT scan shows well-defined, round, heterogeneous mass in superior segment of right lower lobe, composed of multiple nodular calcifications and small fatty components. Contrast enhanced CT shows heterogeneous enhancement of the mass. Right lower lobe lobectomy was done. On microscopic findings, pulmonary parenchymal hamartoma composed predominantly of irregular and broad cartilage masses. The cartilage is surrounded by a rim of fat or fibromyxoid connective tissue. The peripheries are lined by respiratory epithelium.
Brief Review: Hamartoma are relatively common pulmonary tumors, representing about 5 percent of solitary lung nodules. They occur most often in males, the gender predominance benign 2 or 3 to 1.
A hamartoma may be defined as a developmental malformation composed of tissues that normally constitute in organ in which the tumor occurs, but in which the tissue elements, although mature, are disorganized. In the lung, the term traditionally refers to a well-defined tumor consisting predominantly of cartilage and adipose tissue. It can occur within the lung parenchyma or in an endobronchial location.
Radiologically, pulmonary hamartomas typically are well-defined, solitary nodules without lobar predilection. The majority are smaller than 4cm in diameter, although some occasionally grow to a very large size. Although some studies have reported an incidence of calcification as high as 25 to 30 percent, others have identified it far less often. When calcification is present, however, the roentgenographic pattern most often resembles popcorn, a finding that is almost diagnostic. The presence of fat and calcium make the CT diagnosis exquisitely accurate. In a report of 47 lesions studied by CT, 30 (63.8%) contained fat only (n=18), calcium and fat (n=10) or calcium alone (n=2). Thin sections must be used to identify fat with certainty. On thicker sections, a small cavity may be confused with fat because of partial volume averaging.
In the absence of the characteristic calcification or fat, the differential diagnosis includes all other solitary pulmonary nodules, particularly carcinoma.
References: 1. Fraser RS, Pare J.A.Peter, Fraser RG, Pare P.D. Synopsis of Diseases of the Chest. 2nd edition. W.B. Saunders Company. 1994: 518-522.
2. Naidich DP, Webb WR, Muller NL, Krinsky GA, Zerhouni EA, Siegelman SS. Computed Tomography and Magnetic Resonance of the Thorax. New York. Lippincott-Raven. 1999 : 321
Keywords: Lung, Benign tumor,

No. of Applicants : 25

▶ Correct Answer : 19/25, 76.0%

- Annecy Hospital, France Rafik Mahdi
- Centre d'imagerie Jacques Callot, Nancy, France Lionel Cannard
- Central Hospital of the Ministry of Interior, Budapest, Hungary Kalman Judit
- CHU Nancy-Brabois, France Denis Regent
- Cheongju St. Mary Hospital, Korea Jeong-Geun Yi
- CIM Saint Dizier, France JC Leclerc
- CIM Saint Dizier, France J. Marlin
- Centre d'imagerie Jacques Callot, Nancy, France Lionel Cannard
- Ewha Women's University Hospital, Korea Sung Shine Shim
- Hangang Sacred Heart Hospital, Korea Eil Seong Lee
- Incheon Sarang Hospital, Korea Jung Hee Kim
- Kyunghee University Hospital, Korea Kyung Ran Ko
- Maimonides Medical Center, N.Y., USA Naomi Twersky
- Mallinckrodt Institute of Radiology, USA Jin Mo Goo
- MH(CTC), Pune, India Vivek Sharma
- Ondokuz Mayis University, Samsun, Turkey Cetin Celenk
- Seoul National University Hospital, Korea Jung-Gi Im
- Social Security Hospital, Ankara, Turkey Meric Tuzun
- Upasana Hospital, Kollam, India Joy A Thomas

▶ Semi-Correct Answer : 1/25, 4.0%

- Annecy Hospital, France Gilles Genin

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 308 Date 2003-09-20

Discussion

No. of Applicants : 25