대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Mucinous adenocarcinoma of thymus

Radiologic Findings

Fig 1. Chest radiograph shows a right paramediastinal mass with cardiomegaly. Peribronchial cuffing with air space consolidation of the right upper lung field is also noted.
Fig 2. Non-enhanced (left) and enhanced (middle) CT images with mediastinal window setting show a huge anterior mediastinal mass with extensive punctate and amorphous calcifications. The tumor is poorly enhanced and encases the great vessels with luminal narrowing of the superior vena cava. Air-space consolidation in the right upper lobe is also noted. Contrast-enhanced CT with lung window setting (right) shows peribronchial cuffing with interstitial thickening in the right upper lobe.
Fig 3. Anterior mediastinal mass shows intermediate signal intensity on fat suppressed T1-weighted image (left). Signal voids suggesting calcifications are also noted. Tumor shows heterogeneous high signal intensity on fat suppressed T2-weighted image (middle). Air-space consolidation and peribronchial cuffing are also noted. Tumor shows heterogeneous enhancement on fat suppressed contrast-enhanced T1-weighted image (right).

Brief Review

Thymic mucinous adenocarcinoma is an extremely rare tumor with a poor prognosis (1) and is classified as adenocarcinoma enteric type or adenocarcinoma NOS according to the expression of at least one intestinal marker, such as cytokeratin 20 (CK20), caudal type homeobox 2 (CDX2), and mucin-2 (MUC2) (2). Thymic mucinous adenocarcinoma may present as a heterogeneous solid or cystic mass and calcifications may be observed (3).

References

1. Himuro N, Kitami A, Tanaka Y, Ohashi S, Suzuki K, Ohara J, et al. STK11/LKB1 Mutation-positive Primary Thymic Mucinous Adenocarcinoma Accompanied by Cerebellar Metastasis: A Case Report and Literature Review. Clinical Lung Cancer 2021;22:e659-e664
2. Marx A, Chan JK, Chalabreysse L, Dacic S, Detterbeck F, French CA, et al. The 2021 WHO classification of tumors of the thymus and mediastinum: what is new in thymic epithelial, germ cell, and mesenchymal tumors? Journal of Thoracic Oncology 2021
3. Koo YH, Lee JW, Park JS, Shin KE, Lee H, Chin S. Primary Thymic Mucinous Adenocarcinoma: A Case Report Focusing on Radiological Findings and Review of the Literature. Iranian Journal of Radiology 2020;17

Keywords