Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Pulmonary epithelioid hemangioendothelioma
- Radiologic Findings
- Fig 1: Chest PA shows multiple small nodules in both lungs.
Figs 2-4: Axial CT images with mediastinal and lung window settings reveal poorly enhancing nodules in both lungs that have grown slowly over a 2-year interval.
Fig 5: Axial PET/CT image shows multiple mildly hypermetabolic nodules in both lungs (SUVmax 2.9).
- Brief Review
- Pulmonary epithelioid hemangioendothelioma (PEH) is a rare, low-grade malignant vascular neoplasm of the lung. While epithelioid hemangioendothelioma can occur in various body sites and metastasize to the viscera, bones, and soft tissues, the most common sites of involvement are the liver (21% of patients), bone (14%), and lung (12%).
Clinical Presentation: PEH typically manifests as multiple bilateral lung nodules, often discovered incidentally in middle-aged women, with a mean patient age of 40 years. Symptomatic patients may experience chest tightness, shortness of breath, and difficulty breathing after exertion.
Imaging Characteristics: PEH usually presents as multiple well-defined nodules scattered throughout the lungs. Solitary lesions are rare, and nodule diameters are typically 1–2 cm, although diameters >5 cm have been reported. Calcifications and ossifications may occasionally be observed in the lesions, often presenting as benign patterns such as central or popcorn-like calcification. If the lesions invade the pleura, changes such as pleural thickening and effusion may occur. PET/CT imaging often reveals mildly hypermetabolic nodules with an average SUVmax of about 3.0, though some nodules can be non-FDG avid. The metabolic activity is generally lower compared to more aggressive malignancies.
Histopathology: Histologically, PEH is characterized by epithelioid endothelial cells arranged in trabecular or nested patterns. The tumor exhibits mild to moderate atypia with a low mitotic rate. Some tumor nodules may show acellular zones accompanied by coagulation necrosis, calcification, and ossification. Immunohistochemistry often reveals positivity for endothelial markers such as CD31, CD34, factor VIII, Friend leukemia integration 1 transcription factor, Ulex europaeus agglutinin type 1, and FKBP12.
Management and Prognosis: Treatment strategies for PEH vary and can include surgical resection, radiotherapy, chemotherapy, or targeted therapy, depending on the tumor's extent, tumor growth, involved organs, and the patient's overall health. For asymptomatic patients with diffuse lesions, watchful waiting is a viable option, and spontaneous regression has been reported. Prognosis varies widely but is generally favorable compared to more aggressive lung malignancies, with many patients achieving long-term survival. The average survival time for patients with asymptomatic pulmonary nodules is approximately 15 years, and it can exceed 25 years in the best cases. Patients who undergo complete surgical removal of lung lesions often experience long remissions or even cures. However, regular follow-up is crucial to monitor for potential recurrence or progression.
- References
- Frota Lima, Livia Maria et al. “Epithelioid hemangioendothelioma: evaluation by 18F-FDG PET/CT.” American journal of nuclear medicine and molecular imaging vol. 11,2 77-86. 15 Apr. 2021
Jang, Jong Keon et al. “A Review of the Spectrum of Imaging Manifestations of Epithelioid Hemangioendothelioma.” AJR. American journal of roentgenology vol. 215,5 (2020): 1290-1298. doi:10.2214/AJR.20.22876
Shao, Jinchen, and Jie Zhang. “Clinicopathological characteristics of pulmonary epithelioid hemangioendothelioma: A report of four cases and review of the literature.” Oncology letters vol. 8,6 (2014): 2517-2522. doi:10.3892/ol.2014.2566
- Keywords