대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Localized fibrous tumor of pleura

Radiologic Findings

Chest CT shows a well-demarcated, pleural-based, heterogeneous tumor of about 8.4 cm with eccentric, solid portion of little enhancement (35 HU on enhanced CT, which makes net enhancement to be about 6 HU). The tumor contains large portion of, mimicking air meniscus sign. The upper lateral portion of the tumor is composed of multiseptated air densities and discoid atelectasis (arrow).
Gross finding of the tumor (fragmented) shows partly creamy, white to tan, whorled, and firm appearance and partly myxoid feature. Microscopically, the tumor consists of uniform fibroblastic spindle cells. The stroma is partly hyalinized, myxoid, degenerated, and hemorrhagic. There is no mitosis.

Brief Review

Localized fibrous tumor of pleura (LFTP) is a rare mesenchymal neoplasm. Typically, radiography and CT demonstrate well-defined lobular solitary nodule or mass which may appear to be in the lung periphery, abutting a pleural surface and forming obtuse angles against the pleura is located within a fissure. Large lesions are typically heterogeneous due to hemorrhage, necrosis, or cystic and myxoid changes.
However, there is a report about an extremely rare case of an LFTP manifesting as an air-containing cystic mass. The cause of internal air space formation of the tumor is not exactly known. A few possible mechanisms of air-space development in the tumor are suggested. Proliferation and hyalinization of alveolar mesenchymal cells around the bronchus can lead to airway narrowing and distention of distal air space. Air meniscus may also be induced by disparate rates of contraction between the tumor and the capsule, possibly after tumor hemorrhage or due to communication with airway after peritumoral hemorrhage. Peripheral lung tissue entrapped by the tumor may have resulted in air trapping within the tumor through the communicated bronchioles, and eventually, the air space may have enlarged through both check-valve mechanism and tumor growth.

References

1. Melissa L., Rosado-de-Christenson, et al. Imaging features of solitary fibrous tumors. Radiographics 2003;23:759-783
2. Ji Eun Baek, Myeong Im Ahn, et al. Solitary fibrous tumor of the pleura manifesting as an air-containing cystic mass: Radiologic and histopathologic correlation. Korean J Radiol 2013;14(6):981-984

Keywords

Pleura, Benign tumor,