Clinicopathological features of pulmonary epithelioid hemangioendothelioma: a study of 18 cases
Objective: To investigate the clinicopathological features of pulmonary epithelioid hemangioendothelioma (PEHE). Methods: Eighteen cases of PEHE were collected from August 2011 to December 2018 at the First Affiliated Hospital of Zhengzhou University. All cases were retrospectively studied by hematoxylin and eosin staining and immunohistochemistry (IHC). The clinicopathological features were reviewed; the status of CAMTA1 and TFE3 gene was analyzed and patients' outcome was followed up. Results: Of the 18 cases, there were 11 males and 7 females with a male to female ratio of 1.6 to 1.0. The patients' age ranged from 36 to 68 years (mean 52 years). Twelve cases (12/18) showed a single nodule and six cases (6/18) showed multiple bilateral nodules. Seven cases (7/18) involved other organs besides lung. Seventeen (17/18) patients presented with respiratory symptoms and one patient (1/18) presented with abdominal pain. Grossly, the tumors were greyish-white nodules with indistinct borders. Microscopically the tumor cells were epithelioid and arranged in strands and nests, and cytoplasmic vacuoles were commonly noted. The stroma was myxochondroid or hyaline. By IHC, the tumor cells were positive for CD31(18/18), CD34 (16/18), ERG (18/18) and Fli-1 (18/18); CKpan was focally positive in 5 cases (5/18). TFE3 was positive in 3 cases (3/18), and Ki-67 index ranged from 5% to 30%. FISH analysis showed seventeen cases (17/18) had CAMAT1 rearrangement, one case had TFE3 rearrangement displaying a split signal. Eight patients (8/18) had surgical excision, three patients (3/18) had surgery and chemotherapy, and seven patients (7/18) had chemotherapy only. Four patients (4/18) died of the disease. Conclusions: Patients with PEHE have non-specific symptoms, and correct diagnosis depends on pathologic biopsy and the exclusion of other tumors with epithelioid morphology. Some patients with PEHE have poor prognosis, particularly in those who have multiple nodules, peripheral invasion or metastasis.