Lymphoepithelioma-like carcinoma (LELC) of the lung was first reported in 1987. In the past two decades, there have been just more than 150 cases reported in the literature. This uncommon but distinct form of non-small cell lung carcinoma has a predilection for young non-smoking Asians, without gender distinction. Histologically, it is indistinguishable from undifferentiated nasopharyngeal carcinoma. The carcinogenic role of latent Epstein-Barr virus infection in causing LELC of the lung has been evident almost exclusively in Asians compared with Caucasians. Among the reported cases, more than half were in early resectable stages (I or II) and there was a tendency for peribronchovascular spread with vascular encasement in advanced diseases. In order to establish the diagnosis of LELC of the lung, both nasopharyngeal carcinoma and lymphoma have to be excluded by endoscopic biopsy (with or without magnetic resonance imaging of the nasopharynx) and immunohistochemical staining of the biopsy samples. The mainstay of treatment for early-stage disease is curative surgical resection, whereas multimodality treatment (surgery, chemotherapy, radiotherapy) has been adopted in advanced or metastatic diseases. The overall survival is more favourable in LELC of the lung compared with non-LELC type of non-small cell lung carcinoma. Future collaborative studies especially on optimizing treatment for this uncommon malignancy are clearly warranted.

Lymphoepithelioma-like carcinoma of the lung: radiologic features of an uncommon primary pulmonary neoplasm.AJR Am J Roentgenol. 2006 May;186(5):1294-9.

OBJECTIVE: The purpose of this study was to review the chest radiographic, CT, and MRI appearances of primary pulmonary lymphoepithelioma-like carcinoma (LELC). CONCLUSION: Primary pulmonary LELC is histopathologically identical to nasopharyngeal carcinoma. The radiographic, CT, and MRI features of primary pulmonary LELC are nonspecific, often resembling those of bronchogenic carcinoma. Primary pulmonary LELC usually presents as a poorly circumscribed, enhancing, peripheral solitary pulmonary nodule on CT; necrosis may be present and is considered a poor prognostic sign. MRI shows isointense to low-intensity signal on T1-weighted images and mildly increased signal on T2-weighted images; enhancement of abnormal tissue is typical. Most patients present with early-stage disease. Primary pulmonary LELC should be suspected in selected patients and requires differentiation from bronchogenic carcinoma and metastatic nasopharyngeal carcinoma.

Lymphoepithelioma-like carcinoma of the lung: case in which the patient has been followed up for 7 years postoperatively.Jpn J Thorac Cardiovasc Surg. 2005 Dec;53(12):653-6.

Primary lymphoepithelioma-like carcinoma (LELC) of the lung is a very rare disease. There is very little long term follow-up data about this disease. A 60-year-old woman was found to have abnormalities according to a routine chest X-ray examination. She was admitted to our hospital in March 1998. Since a malignant tumor of the right lung was suspected, surgical resection was performed in April of the same year. Pathological diagnosis was LELC of the lung. Its pathological stage was T1N0M0 stage IA. It has been reported that this carcinoma is associated with Epstein-Barr virus (EBV) infection. However, the patient's tumor cells were negative for EBV as examined with RNA in situ hybridization technique. She is alive and has been free from recurrence of the disease over 7 years postoperatively.

Primary lymphoepithelioma-like carcinoma of the lung.Tuberk Toraks. 2005;53(1):69-73.

Lymphoepithelioma-like carcinoma (LELC), best known to occur in the nasopharynx, can arise in a variety of sites, such as the salivary gland, thymus, lung, stomach, and skin. Primary LELC of the lung is very rare, with only limited information in the literature. We presented a case of a 66-year-old white man with a T2N0M0 lymphoepithelioma-like carcinoma of the lung. Immunohistochemical analysis was negative for Epstein-Barr virus. Observation of the nasopharynx and a computerized tomography of the cavum were normal.

Computed tomography characteristics of advanced primary pulmonary lymphoepithelioma-like carcinoma.Eur Radiol. 2003 Mar;13(3):522-6. Epub 2002 Jul 16.

Our objectives were to document CT features of advanced primary pulmonary lymphoepithelioma-like carcinoma (LELC) and to determine features that may assist differentiation from other non-small cell lung cancers (NSCLC). Imaging and clinical data of all patients with biopsy-proven pulmonary LELC ( n=12) were retrieved from a database of all NSCLC patients over a 2-year period. Twenty-five controls were recruited from other inoperable non-LELC NSCLC patients from the database. Pre-treatment CT scans of the thorax of both study and control patients were reviewed for lobe involved; tumour site, borders and size; and pleural, vascular or pulmonary involvement. Presence of lymphangitis carcinomatosis was noted. Lymph node metastasis was characterised as ipsilateral or contralateral enlarged (>1 cm) mediastinal or hilar nodes, or as peribronchovascular nodal spread. Differences between the two groups were tested using Mann-Whitney rank-sum test. The LELC tumours were significantly larger (45.67 vs 17.71 cm(2)) than controls and were closely associated with the mediastinum. There were more LELC tumours with well-defined borders ( p<0.001) and fewer with spiculated borders ( p<0001) than non-LELC tumours. There was increased peribronchovascular nodal spread ( p=0.01) and vascular encasement ( p=0.02) in LELC compared with non-LELC tumours. Advanced primary pulmonary LELC has distinct radiological features, and can appear as well-defined tumour closely associated with the mediastinum, with peribronchovascular spread and vascular encasement.

Clinicopathologic features and prognosis of lymphoepithelioma-like carcinoma of the lung.Zhonghua Bing Li Xue Za Zhi. 2001 Oct;30(5):328-31.

OBJECTIVE: To analyze the clinicopathologic features and prognosis of lymphoepithelioma-like carcinoma (LELC) of the lung. METHODS: 26 cases of pulmonary LELC with available long-term follow-up information were compared with 84 cases of pulmonary non-LELC(33 cases of squamous cell carcinoma, 36 cases of adenocarcinoma, 6 cases of adeno-squamous carcinoma and 9 cases of large cell carcinoma) with available long-term follow-up information using Kaplan-Meier method and the generalized Wilcoxon test. RESULTS: LELC of the lung had a better prognosis than non-LELC (P < 0.05). Further study showed that pulmonary LELC had a significantly better prognosis than adeno-squamous carcinoma and large cell carcinoma. However, there was no significant prognostic differences between pulmonary LELC and squamous cell carcinoma and adenocarcinoma. Tumor recurrence and necrosis (> or = 5% of tumor) were associated with poor prognosis. CONCLUSION: Pulmonary LELC, which is a very rare and unique entity, has a better prognosis after therapy.

Lymphoepithelioma-like carcinoma of the lung with a better prognosis. A clinicopathologic study of 32 cases.Am J Clin Pathol. 2001 Jun;115(6):841-50.

The purpose of our study was to clarify the prognosis of lymphoepithelioma-like carcinoma (LELC) of the lung, which is rare. We analyzed the clinicopathologic features of 32 cases of pulmonary LELC and compared the cases with 84 cases of pulmonary non-LELC with available long-term follow-up information. The results show that LELC of the lung as a distinct entity has a better prognosis than non-LELC. We found a significant difference in the survival rates between patients with LELC and patients with non-LELC in stage II and stages III and IV, respectively. Tumor recurrence and necrosis (5% or more of tumor) are associated with a poor prognosis. It seems that the histologic typing (Regaud type and Schmincke type) of pulmonary LELC is of no clinical value.

Primary lymphoepithelioma-like carcinoma of the lung. A clinicopathologic study of 11 cases. Cancer. 1995 Aug 1;76(3):413-22.

BACKGROUND. Lymphoepithelioma-like carcinoma (LELC), best known to occur in the nasopharynx, can arise in a variety of sites, such as the salivary gland, thymus, lung, stomach, and skin. Primary LELC of the lung is very rare, with only limited information in the literature. METHODS. The clinicopathologic features of 11 patients with pulmonary LELC collected from two regional hospitals in Hong Kong are described. RESULTS. The patients, all Chinese, were aged 38 to 73 years (median, 54 years), with equal sex incidence. Two of the 8 patients were smokers. Four presented with coin lesions incidentally discovered on chest X-ray, five with cough and blood-stained sputum, and two with pleural effusion. The tumor formed a discrete (9 patients) or an ill-defined (1 patient) nodule in the lung, or, rarely, showed extensive bilateral pulmonary involvement (1 patient). The major bronchi were not involved except in 1 patient. Three patients had lymph node metastasis at presentation; two of them had bone metastasis, one at presentation and one after 9 months. The tumors had pushing margins, and grew in the form of anastomosing islands and sheets, comprising syncytial-appearing large cells with vesicular nuclei and prominent nucleoli. They were infiltrated by an appreciable number of small lymphocytes and plasma cells. Intratumoral amyloid globules were found in one tumor. In five patients, the tumor showed intraepithelial growth within the small bronchi; this could represent either the in-situ phase of the tumor or pagetoid spread into the bronchial epithelium. The neoplastic cells of all patients harbored Epstein-Barr virus (EBV) as demonstrated by in situ hybridization for EBV-encoded small nuclear RNAs. All eight Asian patients with pulmonary LELC previously reported in the literature similarly have been EBV-positive, whereas the four reported Caucasian patients all have been EBV-negative. CONCLUSION. Lymphoepithelioma-like carcinoma of lung occurring in Asians is an EBV-associated neoplasm; it also appears to occur at a higher frequency in Asians than Caucasians. It usually presents as a solitary subpleural nodule, and there is no strong association with cigarette smoking. Most patients have early stage disease at presentation. From the limited available data, the behavior of LELC of lung is highly variable, ranging from apparent curability by excision (particularly for localized disease) to highly aggressive, extensive disease at presentation.