대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Perivascular epitheloid cell tumor (PEComa) of the lung

Radiologic Findings

Fig 1. Chest radiograph shows a small nodule in the right upper lung field.
Fig 2. Axial non-enhanced and enhanced CT images show a 1cm sized well defined nodule with vivid enhancement in the right upper lobe.
Fig 3. Non-enhanced axial CT image obtained 2.5 years ago shows a 0.7cm well defined nodule in the right upper lobe.
Fig 4. Enhanced axial CT image obtained after 6 months demonstrates little change of a nodule in the right upper lobe.
Fig 5. FDG PET-CT scan shows no FDG uptake in the nodule.

Brief Review

Perivascular Epithelioid Cell Tumor (PEComa) is a rare mesenchymal neoplasm which is thought to originate from perivascular epithelioid cells showing both melanocytic and myogenic differentiation [1]. The lung is an uncommon location for PEC tumor, which is otherwise commonly seen in the gastrointestinal tract and pelvic organs. Pulmonary PEC tumors also are mostly benign [2], with malignancy being very rare [3].
Patients with pulmonary PEC tumors usually range in age from 40 to 60 years and are equal in prevalence among both genders. Most PEC tumors present mostly as a peripheral, well-defined, enhancing, and round nodule without cavitation or calcification. Intense post-contrast enhancement is one of the characteristics of the PEC tumor and this appears to be related to rich vascular stroma [4].

References

1. Folpe, A. L., & Kwiatkowski, D. J. (2010). Perivascular epithelioid cell neoplasms: pathology and pathogenesis. Human pathology, 41(1), 1-15.
2. Liebow, A. A., & Castleman, B. (1971). Benign clear cell (" sugar") tumors of the lung. The Yale journal of biology and medicine, 43(4-5), 213.
3. Martignoni, G., Pea, M., Reghellin, D., Zamboni, G., & Bonetti, F. (2008). PEComas: the past, the present and the future. Virchows Archiv, 452(2), 119-132.
4. Lim, H. J., Lee, H. Y., Han, J., Choi, Y. S., & Lee, K. S. (2013). Uncommon of the uncommon: malignant perivascular epithelioid cell tumor of the lung. Korean journal of radiology, 14(4), 692-696.

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