대한흉부영상의학회 Weekly Chest Cases

Case No : 1456 Date 2025-09-15

Courtesy of Taehee Lee, Hye Soo Cho, Woo Hyeon Lim / Seoul National University Hospital
Age/Sex 49 / M
Chief ComplaintFever, s/p left pneumonectomy for aspergillosis (30 years ago)

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Diagnosis With Brief Discussion

Diagnosis: Pyothorax-associated lymphoma
Radiologic Findings: Fig 1. Chest PA radiograph shows a large mass with rim calcification occupying the left hemithorax.
Fig 2-4. CT scans demonstrate a substantial mass within the left pneumonectomy cavity, featuring an enhancing soft tissue component and a protrusion into the anterior chest wall. A small lymph node is noted at the level of the left 8th/9th rib.
Fig 5. MRI reveals a strongly diffusion-restrictive lesion corresponding to the protruding mass in the anterior chest wall. The upper image represents the B1000 sequence, while the lower image shows the Apparent Diffusion Coefficient (ADC) map.
Brief Review: Pyothorax-associated lymphoma (PAL) is a rare type of non-Hodgkin's lymphoma strongly linked to long-standing chronic empyema, often resulting from artificial pneumothorax therapy for tuberculosis, which was common before 1970. The latency period between therapy and PAL onset typically exceeds 20 years, and in many cases, stretches beyond 40 years. This disease primarily affects men with a mean diagnosis age of 60–71 years. Symptoms include chest pain, palpable chest wall masses, respiratory issues, and systemic signs like fever and weight loss. Histologically, PAL is most commonly diffuse large B-cell lymphoma, frequently associated with Epstein-Barr virus (EBV) infection.
Imaging studies, including chest radiographs, CT scans, and gallium scans, are critical for diagnosing PAL. On chest radiographs, PAL typically appears as extrapulmonary soft-tissue masses associated with empyema cavities, often accompanied by pleural calcifications and chest wall abnormalities. On CT imaging, pyothorax-associated lymphoma (PAL) typically presents as a soft-tissue mass adjacent to an empyema cavity. These masses are commonly lenticular (60%) or crescent-shaped (20%) and are eccentrically located along the empyema margin. Internally, they are heterogeneous, with necrotic areas observed in 60% of cases—a distinctive feature of PAL. The masses are most often found on the lateral costal pleura (50%) or the costophrenic angle (30%). Chest wall invasion is common (75%), often involving osteolytic rib lesions (50%). Air-fluid levels or air bubbles within the empyema cavity frequently indicate fistula formation caused by tumor invasion, a finding that helps distinguish PAL from benign empyema complications. PAL masses usually exhibit external or symmetric growth, with rare internal expansion. They often invade adjacent structures such as the chest wall, ribs, lung parenchyma, and, in some cases, the abdominal cavity via the diaphragm. The relationship between the mass and the empyema cavity is a key diagnostic feature, with the masses always located at the empyema’s edge. This positional clue aids in guiding biopsies. CT is crucial for identifying PAL, differentiating it from benign empyema or other malignancies, and assessing disease extent for optimal management.
PAL has a poor prognosis, with a high mortality rate. Most patients succumb within two years of diagnosis despite treatments, which may include chemotherapy, radiation therapy, or combinations of both. Its malignant nature and rare occurrence emphasize the importance of early detection.
References: 1. Ueda T, Andreas C, Itami J, Miyakawa K, Fujimoto H, Ito H, Roos JE. Pyothorax-associated lymphoma: imaging findings. AJR Am J Roentgenol. 2010 Jan;194(1):76-84.
Keywords

No. of Applicants : 84

▶ Correct Answer : 60/84, 71.4%

- Funabashi General Hospital , Japan MANABU AKIMOTO
- Saitama-Sekishinkai Hosptal , Japan MIHOKO YAMAZAKI
- , Japan SUZUNE TSUKAMOTO
- medical scanning , Japan HIROAKI ARAKAWA
- IUHW Narita Hospital , Japan ISSEI FUKUDA
- ZIGONG TCM HOSPITAL OF CHINA , China CAO CUN YOU
- Shiga University of Medical Science , Japan AKITOSHI INOUE
- Kyoto University , Japan AKIHIKO SAKATA
- McGill University Health Center , Canada ALEXANDRE SEMIONOV
- Oita university , Japan AYUMI KAMEI
- Kyoto City Hospital , Japan YUSUKE UTSUNOMIYA
- , Italy PAOLO BALDASSARI
- , France CHARLES DAMIEN
- Teikyo University Hospital , Japan CHIAKI SATO
- Vita Hospital , Brazil DIOGO LAGO PINHEIRO
- Kyeongpook National University Hospital , Korea (South) JUNGMIN LEE
- , China FANG YING GEN
- Chonbuk National University Hospital , Korea (South) YONG HWAN JO
- Oita University, Faculty of Medicine , Japan FUMITO OKADA
- Seoul Medical Center , Korea (South) HYUK GI HONG
- university of montreal , Canada Andrei Bogdan Gorgos I
- Osaka University , Japan AKINORI HATA
- The University of Tokyo Hospital , Japan TOSHIHIRO FURUTA
- , Japan YOSHIKI ISHII
- University of Yamanashi , Japan HIROAKI WATANABE
- Narayana Multispeciality Hospital Jaipur Rajasthan , India JAINENDRA JAIN
- Inje University Pusan Paik Hospital , Korea (South) JIYEON HAN
- Yonsei University,Severance Hospital , Korea (South) JUN GU KANG
- Japanese Red Cross Otsu Hospital , Japan JUN YOSHIDA
- Oita university , Japan NORITAKA KAMEI
- , Japan KENTARO KOTANI
- Chonbuk National University Hospital , Korea (South) YEEUN LEE
- Other , Korea (South) CHAEHUN LIM
- Osaka Metropolitan University Hospital , Japan SHU MATSUSHITA
- , Japan SHUNJIRO NOGUCHI
- , Japan MARINO TANIGUCHI
- , Japan MASAMICHI IWAI
- University of Tsukuba, Dept of Radiology , Japan MANABU MINAMI
- Shiga General Hospital , Japan YUSAKU MORIBATA
- Avrasya Hospital/ISTANBUL , Turkey MURAT ULUSOY
- Eskisehir Sehir Hastanesi , Turkey MURAT SAHIN
- , Japan HIROAKI OKADA
- Osaka metropolitan university Hospital , Japan TATSUSHI OURA
- Department of Radiology, Nara Medical University Hospital, Nara, Japan , Japan KATSUTOSHI HORIUCHI
- GHICL , France MANUEL TOLEDANO
- TB centre kasaragod. , India rikhy krishnan
- Korea University Anam Hospital , Korea (South) KYU-CHONG LEE
- Kyoto University , Japan SHO KOYASU
- Kobe Children , Japan SHUHEI NORIMOTO
- Yonsei University,Severance Hospital , Korea (South) SEO BUM CHO
- Kantou Rousai Hospital , Japan KAORU SUMIDA
- Other , Korea (South) DONG HAN SHIN
- Matsunami General Hospital , Japan TARO TAKEDA
- Ehime University , Japan KOTARO MATSUMOTO
- , Japan YUMI MAEHARA
- Nara medical university , Japan HIROHIDE WATANABE
- Toyota Kosei Hospital , Japan YUKI HAYASHI
- Chonbuk National University Hospital , Korea (South) HYEONG RYUN CHO
- University of Yamanashi , Japan KOJIRO ONOHARA
- Jiangsu province hospital , China WANGJIAN ZHA

▶ Correct Answer as Differential Diagnosis : 10/84, 11.9%

- Secomedic Hospital , Japan FUMINORI MIYOSHI
- University of Yamanashi , Japan TAKAAKI HASHIMOTO
- University of Yamanashi , Japan HIROYUKI MORISAKA
- , Japan KANGO KUWABARA
- Chonbuk National University Hospital , Korea (South) SEUNG HO LEE
- Jichi Medical University, School of Medicine , Japan MITSURU MATSUKI
- Seoul National University Bundang Hospital , Korea (South) YOONAH DO
- Kyung Hee University Medical Hospital , Korea (South) JEONG TAEK YOON
- Fukuoka university , Japan KEISUKE SATO
- Ehime University , Japan TOMOHISA OKADA

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 1456 Date 2025-09-15

Discussion

No. of Applicants : 84