대한흉부영상의학회 Weekly Chest Cases

Case No : 415 Date 2005-10-10

Courtesy of Jae Seung Seo, MD, Hae Ryoung Kim, MD, Young Nyun Park, MD, Kyu Ok Choe, MD / Shinchon Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
Age/Sex 78 / M
Chief ComplaintAbnormal chest radiograph during staging work up of non-Hodgkin’s lymphoma in the left thigh

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Diagnosis With Brief Discussion

Diagnosis: Schwannoma
Radiologic Findings: On chest radiograph, faintly delineated mass at left 4th intercostals space is seen. Early and delayed-enhanced axial chest CT scan reveals a mass has a well-defined margin, obtuse angle with the pleura, and persisting target-like enhancement. The mass abuts adjacent chest wall with preserved extrapleural fat plane. PET scan shows mild uptake on the mass in left chest wall and intense uptake in the mass in right thigh.

Excision of the mass in left chest wall was performed. The specimen consists of an ovoid mass, measuring 4x3x2cm. The external surface is smooth with areas of attached skeletal muscle. The mass was well encapsulated and the cut surface was pinkish, tan, myxoid, and degenerated appearance. Finally, the mass was confirmed as a schwannomag.
Brief Review: Schwannomas are arising from peripheral nerves and nerve sheath like neurofibroma and malignant peripheral nerve sheath tumor. The tumor are usually well encapsulated and spherical and more common in adults. Schwannomas are composed of spindle cells densely packed together (Antoni A pattern) or organized more loosely in association with a myxoid stroma (Anotoni B pattern). The area of infarction are common.

On plain radiographs, the tumor appears as sharply-marginated, round, elliptical, or lobulated extrapleural mass, occurring in relation to the vagus, phrenic, or recurrent laryngeal nerves, or along the courses of intercostals nerves. Associated rib or vertebral deformity or enlargement of a neural foramen is visible in about 50% of cases.

On chest CT, the tumor typically appears as well marginated, smooth, rounded or elliptical low attenuated masses, up to 73% and usually has mixed attenuation attributable to confluent areas of hypocellularity adjacent to densely cellular or collagenous regions, xanthomatous change, or regions of cystic degeneration. Variable enhancement of the tumor may be seen; peripheral enhancement is more common. Small areas of calcifications are seen in 5% to 10 % of cases. Pressure deformity, displacement of the adjacent ribs and vertebrae, inferior rib notching, and neural foraminal enlargement could be associated.

On MRI, the tumor has slightly higher signal intensity than muscle on T1-weighted images and marked increased signal intensity on T2?weighted or contrast-enhanced images, although often in an inhomogeneous fashion. On T2-weighted or contrast-enhanced images, the center of the lesion may have a higher or lower intensity than its periphery. Extension into the spinal canal is present in 10% and is best demonstrated with MRI.
References: Please refer to Case 384
Keywords: Chest wall, Benign tumor,

No. of Applicants : 34

▶ Correct Answer : 16/34, 47.1%

- Busan National UniversityHospital, Korea Su-mi Shin
- Pgimer, Chandigarh, India Ramprakash Galwa
- Pgimer, Chandigarh, India Ashish Gupta
- Riverside Radiology Associates, Columbus, Ohio, USA Sumit Seth
- Chikuhou Rosai Hospital, Japan Uchida Kouei
- Dong-Eui Medical Center, Busan, Korea Hoon Sik Jung
- Radiologie Guiton, La Rochelle, France Denis Chabassiere
- Cabinet de Radiologie Guiton, La Rochelle, France Jean-Luc Bigot
- Gwangmyoung Sungae Hospital, Korea Jiyong Rhee
- Shiga University, Shiga, Japan Yukihiro Nagatani
- Social Security Hospital, Ankara, Turkey Meric Tuzun
- Max Hospital, New Delhi, India Vickrant Malhotra
- Samsung Medical Center, Seoul, Korea Ha Young Kim
- Kosin University Gospel Hospitalm Busan, Korea Mi Hee Jung
- University of Pennsylvania, USA Lisa Jones
- Ping Tung Christian Hospital,Taiwan Chi Kuei Hsu

▶ Correct Answer as Differential Diagnosis : 6/34, 17.6%

- Ping Tung Christian Hospital,Taiwan Jun-Jun Yeh
- Hanyang University Hospital, Seoul, Korea Yo Won Choi
- Homs National Hospital, Homs, Syria Rami Abou Zalaf
- Monaldi Hospital, Naples, Italy Gaetano Rea
- Annecy Hospital, France Gilles Genin
- Annemasse, Polyclinique de Savoie, France Gay-Depassier

▶ Semi-Correct Answer : 1/34, 2.9%

- Max Hospital, New Delhi, India Anurag Jain

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 415 Date 2005-10-10

Discussion

No. of Applicants : 34