대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Vascular malformation

Radiologic Findings

Fig 1. Chest PA shows ill-defined opacity in the left upper lung field paramediastinal area, with preserved outline of hilum and left cardiac border.
Fig 2-6. In CT, a heterogeneous mass with interspersed fat attenuation was identified in the posterior mediastinum. The mass contained a tiny calcification, presumed to be phlebolith. Solid areas showed mild enhancement (55HU-> 80HU). In the coronal image, the overall mass extent measured 14 cm.
Fig 7-10. In MR, the mass showed heterogenous signal intensities, low in T1 and high in T2, with fat components. Engorged draining veins were seen in gadolinium enhanced images.

Brief Review

Initially, a CT-guided biopsy was performed, and only fibroadipose tissue was identified on histopathologic examination. The patient next had mass excision through VATS, and it was confirmed that the mass was a vascular malformation with dilated lymphatic tissue. The immunohistochemical staining revealed positivity for ERG and D2-40, specific markers for endothelium and lymphatic endothelium.
Vascular malformations are congenital anomalies and show no regression. They may be infiltrative and usually involve multiple tissue planes. According to the preponderant vascular channels, vascular malformations are classified as venous, lymphatic, capillary, arterial, or combined. Imaging is useful not only for diagnosis but also for determining the extent and relationship of the vascular malformation to the adjacent structures.
Venous malformations are usually septated lesions with intermediate to decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted and STIR images. They typically show slow gradual filling with contrast material and may demonstrate characteristic nodular enhancement of tortuous vessels on delayed venous phase images. In cases of thrombosis or hemorrhage, heterogeneous signal intensity can be observed on T1-weighted images. The best clue for identification of a venous malformation is the presence of phleboliths. Associated findings such as subcutaneous fat hypertrophy, muscle atrophy, and fatty replacement are commonly seen.

References

1. Masand, Prakash. “Radiographic findings associated with vascular anomalies.” Seminars in plastic surgery vol. 28,2 (2014): 69-78. doi:10.1055/s-0034-1376266
2. Flors L, Leiva-Salinas C, Maged IM, et al. MR imaging of soft-tissue vascular malformations: diagnosis, classification, and therapy follow-up. Radiographics. 2011;31(5):1321-1341. doi:10.1148/rg.315105213
3. Kunimoto, K., Yamamoto, Y., & Jinnin, M. (2022). ISSVA Classification of Vascular Anomalies and Molecular Biology. International journal of molecular sciences, 23(4), 2358. https://doi.org/10.3390/ijms23042358

Keywords