Pulmonary epithelioid hemangioendothelioma misdiagnosed as a benign nodule

Abstract

Pulmonary epithelioid hemangioendothelioma (PEH) is a rare vascular tumor of borderline malignancy that originates from endothelial cells. Chest computed tomography (CT) performed during a routine cancer screening revealed multiple small pulmonary nodules in a 50-year-old man who had previously undergone endoscopic submucosal dissection of early gastric cancer. To rule out metastatic nodules, a wedge resection of the left upper lobe was performed and the frozen biopsy reported a benign fibrotic nodule. Using immunohistochemistry, the final pathology was indicated to be PEH, and consecutive surgery for the right-side nodules was planned and performed.

Figure 1

The initial chest computed tomography scan. (A) There is a peripheral small nodule with lobulation in the apicoposterior segment of the left upper lobe (arrow). (B, C) Two tiny nodules are noted in the posterobasal segment of the right lower lobe (arrows).

Figure 2

Pathological findings. (A) The nodule is well-demarcated, hyalinized, and within the lung parenchyma (hematoxylin and eosin, ×40). (B) Variable-sized and irregularly shaped tumor cells with round to oval shape nucleus are located in the hyalinized stroma. Some of the neoplastic cells are rich in eosinophilic cytoplasm (×200). (C) There are characteristic intracytoplasmic vacuoles in the tumor cells (arrow; ×400). (D) The tumor cells are immunoreactive for CD31 in the cytoplasm (×400).